Lexus is300 wont start

Lexus is300 wont start DEFAULT

IS not starting as well as usual

Our generally faultless elderly IS ( 04 plate ) has recently not wanted to start with the immediacy we've come to expectit will either crank for several seconds and start reluctantly, or won't start after several seconds, but then fire up straight away at the 2nd time of asking. It then runs fine, and will start with no problem later in the day, unless left for some time, at which point it will misbehave again.

There are several posts about this issue on various Lexus forums, with different opinions about the cause, but seemingly no definitive solution.

If I turn the ignition on for 5 seconds or so before cranking, it seems to helpthat would seem to indicate a fuel pressure issue, with the pump needing a few seconds to restore pressure. Any other thoughts?

fuel pressure for sure, might be a dodgy in tank pump, most probably pressure reg though or fuel filter blocked

Bit off topic but what mpg do you get my mum had the and I always wanted one but with more poke

I left Lexus before these came out, but I'm still in contact with a lot of the lads that stayed and worked on them, none of them can remember any issues, but the Lexus specific forums are full of tales of woe with the same issueI'm going to turn the ignition on in the morning before it's been started, let the pump prime, and crack the fuel feed into the injector rail and see if there's anything going on there pressure wise. I don't think these models have a serviceable fuel filter, so that rules that out.

Wondered if it might be a coolant sensor making the car think it was always hot, and stopping enough fuel getting through for a cold start, but I can't see why it would start no bother on the 2nd time of asking if it were that.

This time of year the battery has to be the main suspect?

Battery was replaced last year with the heaviest duty item that would fit in the space availableit spins over so fast it sounds like it's got no compression

Its easy to check if the fuel system is priming, crack open the fuel rail "in" banjo it should prime with ign on for about 5secs. (obviously this will generate a bit of fuel leaking out!)

These really are quite a simple system & pretty much infallable, my thoughts are has somebody re-wired the car for a stereo or similar & used a wire that goes to to the COR relay or FP relay.

Pull the relays in the engine bay & check for corrosion. I am aware of some older gen cars where a well worn ign switch did similar things, again that will show up by the relays not doing their thing. Could be something as simple as a bad earth but there are several on these to-from the engine to each section & to each part of the loom.

It would be an easy test with a power probe & a wiring diagram. Anyone local familiar with these 2JZ engines could help. Have a look on the Supra forums, I'm sure its an easy find.

cptsideways said:

Its easy to check if the fuel system is priming, crack open the fuel rail "in" banjo it should prime with ign on for about 5secs. (obviously this will generate a bit of fuel leaking out!)

These really are quite a simple system & pretty much infallable, my thoughts are has somebody re-wired the car for a stereo or similar & used a wire that goes to to the COR relay or FP relay.

Pull the relays in the engine bay & check for corrosion. I am aware of some older gen cars where a well worn ign switch did similar things, again that will show up by the relays not doing their thing. Could be something as simple as a bad earth but there are several on these to-from the engine to each section & to each part of the loom.

It would be an easy test with a power probe & a wiring diagram. Anyone local familiar with these 2JZ engines could help. Have a look on the Supra forums, I'm sure its an easy find.

Thanks for the repliesit had a stereo replaced about years ago, as they all do, the standard one always breaks! The new one came with a connector block that was wired wrongly, in that the perm live and ignition live were the wrong way around. However that was an easy fix, and so long ago that I can't realistically see any connection to this.

I remember the ignition switch thing on the early cars, as far as I was aware they simply collapsed and wouldn't allow the key in rather than caused issues like this, but I might not be correct there? Also, I thought they had resolved it by the time the cars were about, but again, I may be wrong.

There are an awful lot of posts on various forums about this, it seems strange that people still seem to find a definitive reason for it to be so elusive. Thanks for your suggestions, I'll pull the relays after checking the fuel pressure, that still seems likely from the symptoms.

Gassing Station | Japanese Chat | Top of Page | What's New | My Stuff


Lexus IS Starter Replacement

The cost of a starter replacement depends on the year, make, and model of your car.

Get a Quote

Find Your Cost

Find Your Cost

Our repairs come with:

Certified Mechanics  •  
Month | 12,Mile Warranty

Easy Online Booking  •  7 Days a Week

Range for All Cars

Free Instant Quote

Average Shop Price $

RepairSmith Price $

Average Shop PriceRepairSmith Price$ Tell us your vehicle to get a guaranteed price for your brakes from RepairSmith.

This range covers an average Starter Replacement. Tell us your car to get a guaranteed price from RepairSmith.

Tell us your vehicle to get a guaranteed price for your brakes from RepairSmith.

Our repairs come with:

Certified Mechanics  •  
Month | 12,Mile Warranty

Easy Online Booking  •  7 Days a Week

Learn more about Starters

RepairSmith offers upfront and competitive pricing. The average cost for Lexus IS Starter Replacement is $ Drop it off at our shop and pick it up a few hours later, or save time and have our Delivery mechanics come to you.

Lexus logo

Lexus IS

L V6 Base • 28, miles

Loomis ,  CA

$ - $

Lexus logo

Lexus IS

L L6 Base • , miles

Novato ,  CA

$ - $

Lexus logo

Lexus IS

L V6 F Sport • 37, miles

San Diego ,  CA

$ - $

Lexus logo

Lexus IS

L V6 Base • 65, miles

Malibu ,  CA

$ - $

Lexus logo

Lexus IS

L L6 • , miles

Long Beach ,  CA

$ - $

Lexus logo

Lexus IS

L L6 • , miles

Los Angeles ,  CA

$ - $

Lexus logo

Lexus IS

L L6 • , miles

Oxnard ,  CA

$ - $

Last Updated:
Sep 7, PM

Get A Quote Month | 12,Mile Warranty

What is a Starter?

The starter helps the car start. It’s really that simple. It’s a small motor (and, as a result, it’s often called the starter motor), that is responsible for getting your car’s primary motor off and running. It’s actually a fairly simple device. While the starter is small, it’s quite powerful. It can turn the car’s motor over at a pretty slow speed (around revolutions per minute, whereas most cars idle just under 1,), but that’s all that is needed to get the motions in your car’s engine going, so that the car can turn on. It’s a pretty cool and somewhat complex operation that I’m guessing you don’t really care about, so here’s the basic version. When you turn key (or press the “ON” button) in your car, the starter motor is activated. It has a gear, called a pinion gear, which attaches to the engine’s flywheel. As the starter turns the engine follows suite, sucking in air and fuel, until it’s up and running at full speed. As for power, the starter gets its juice from the battery. Which is why your car won’t turn on if the battery dies, because the starter has no way of doing its business. It probably goes without saying that your starter gets a lot of use. Every time you use your car, the starter motor has to spring into action. And since it gets used so much, it can wear down rather easily, at which point it will need to be replaced.

Get a Quote 1-Year | 12,Mile Warranty

Symptoms of a failing Starter

Your car won’t start or engine cranks slowly

Did you really need me to tell you this one? The name is right there, and I just explained it. The starter helps the car start. Without a starter, the car can’t start. Do the math. If the starter motor is fully dead, you won’t be able to start your car. End of story. But if the starter is just starting to die, and kind of hanging on to life, then you might experience intermittent starting. The car will sometimes turn on, and sometimes won’t. Not ideal, especially if you’re trying to get somewhere on time. It’s also worth noting that if you’re experiencing intermittent starting, it could be due to some faulty wiring in the electrical system, rather than the motor itself. Or, of course, it could be a battery issue.

Funny noises

This shouldn’t be news to you: your car shouldn’t be making weird noises. If it is, then you’ve likely got an issue on your hands. There are two noises associated with failing starters. If the car won’t turn on, it may be due to the starter motor, as mentioned above. If the car is whining when you try (but fail) to turn it on, then that’s a sure sign that the starter is busted. That noise is due to the starter motor spinning, without being attached to the flywheel. If the car isn’t making that noise, but still won’t turn on, then the issue is likely from something else. If your car is makes a grinding noise when it’s first started, then that also may be the starter. That’s the sound of the starter gear failing to disengage once its work has been done.

Get a Quote 1-Year | 12,Mile Warranty

How urgent is a Starter replacement?

The urgency of a starter replacement is entirely dependent on how much you like driving your car. If you prefer to just sit and stare at your car, then it’s entirely up to you. If you’re like the rest of us and actually prefer to start your car and hit the road, then you’ll want to get your starter replaced asap.

Get a Quote 1-Year | 12,Mile Warranty

Related Lexus IS Repairs

Alternator Replacement Battery Recharge Battery Replacement Battery Terminal Repair Starter Motor Replacement

Not sure? Let us diagnose

Other Repairs

Ball Joint Replacement Radiator Flush Idle Air Control Valve Replacement Brake System Flush Brake Light Switch Replacement Clutch Repair Ignition Coil Replacement Oil Pump Replacement Heater Hose Replacement Left Engine Mount Replacement Lower Intake Manifold Gasket Replacement Engine Motor Mount Replacement Hood Latch Replacement Power Steering Fluid Replacement Rear Control Arm Bushing Replacement Shock Absorber Replacement Tire Pressure Sensor Replacement Brake Rotors Replacement

How can we help?

RepairSmith is here to make car repair easy.

Get a Quote

1-Year | 12,Mile Warranty

  1. Zoo pals pig
  2. Rodent repellent frequency
  3. Leeds craigslist
A limited supply of the original best-selling Lextreme 1UZFE EGR Delete Kitis available for sale. If you own a 1UZ from , you reallyneed to get this kit! Email me at [email&#;protected]for help with ordering or questions.

Please note:we're not an auto parts supplier and I can't respond to inquries for random Lexus and Toyota auto parts. All parts not listed above, including the LS and SC turbo kit, rebuild kits and supercharger are sold out and won't return. The Lextreme performance torque converterhas a very long waiting list. Email me if interested.

LEXTREME LEXUS FORUMS HERE!- Post Questions Here For Quick Answers!

Here are some possible diagnoses why your engine won&#;t start but has power.

Battery and Associated Cables

It is possible the battery is weak and causes the engine not to turn.

However, if you turn on all the lights and blast all the fans and still having trouble turning the engine, then it&#;s most likely not the battery.  Charge the battery and try again.

If charging the battery doesn&#;t help, its most likely not a battery or cable problem.  If the battery is weak, the starter will still engage but very weak or slow.  If the battery is really bad, you might hear the click, click, click, click, click sound.

Anti-Deterrent ECU

This is also a possibility, especially someone else drive your car.

This is very common if you lend your car to someone.  The symptom of this condition is &#;No noise or sound at all&#; when ignition key is turned.  If this is faulty, the symptom will be the complete ignition kill.  Therefore, you will not heard and clicking sound or engine turning at all.

If this is the problem, you can easily reset the Anti-Deterrent by using your key.  Stand out side of the car and close all doors.  Insert the key into the driver side door and turn the key to clockwise and counterclockwise for three four cycles.

Basically, you lock, unlock for 4 times and this procedure will reset the anti-deterrent ECU.  If this happen to you, it&#;s quite scary at first, but the solution is very simple.

Faulty Starter Relay

The easiest way to find out if the starter relay is bad is to open up the engine bay fuse box. You can use a flat screwdriver and take out the cover.

Have a friend try to start the car for you.  If you hear a click sound right at the starter relay (Green Color Square Type Relay) then the relay is good.

Second thing you can do is to borrow a starter relay from a friend.  If the working relay installed and the engine still not turning, then its not faulty relay.

Neutral Start

Believe it or not, the transmission shifter plays a role in starting your car too.  As your car ages, the transmission shifter linkage doesn&#;t give good contact to the starting system and your engine will not turn or click at all.

Here some signs of this problem.

  1. No P (park) or N (Neutral) indicator light while key on.  Even with P & N indicator lights come on but that still doesn&#;t it has good contact.
  2. When you turn on the key, you should not hear anything at all.  No turning or clicking at all.

To test this out, the best way is to push forward on the shifter until you see P while trying to start the car.  Or you can turn the key into on position and hold it there while pushing on the transmission shifter.

Remember this is a very common problem with older cars.

Bypass Starter Circuit

There are many reasons why the engine won&#;t turn.  It is possible the circuitry might be faulty.

However, you can test your starter without taking it out.  You can bypass the circuitry and use a positive (+) into the fuse box.  Here are the procedures:

  1. Open up the fuse box with a flat screwdriver.  The fuse box is located near the battery.
    2. Use a 10 mm socket and loose the fuse/relay module.
    3. From there you need to use the same 10 mm socket and loose the plug.
    3. Once the plug is out, look for a large black wire right under the Green Relay (Starter Relay) See starter diagram below.
    4. Supply the black wire with a power source.  Please be careful do not touch this hot wire to anywhere else.
Use a flat screw driver and loosen the bolts.
This is a typical picture of a LS SC is very similar too.


This is how it looks like when the cover is removed. Use a 10 mm socket and loosen those two 10 mm bolts.
The green relay is the starter relay.
Loosen the bolts and the whole module comes out.
Turn the module upsidedown and use the same 10 mm socket to unbolt the plug.
Once the unplug, you will see the starter relay wire as marked by the red arrow.
This is how you bypass the electronic circuitry.

When you supply power to the black (a large black wire right under the green relay) wire, you are pretty much bypassing ECU, relay and connectors.  If your starter is good, it should turn.  Then the problem might be somewhere before the wire or the starter.

If it doesn&#;t turn, then the starter is almost % faulty.You might hear a click sound but doesn&#;t turn.  This means the starter is engaging into the flexplate, but not turning.  You might hear only one click sound and that is it.

If bypassing didn&#;t cause the starter to turn, then it&#;s time to spend the money and time to replace the starter.I believe this is the easiest way to find out if the starter is bad or not without taking the starter out.

Faulty starter is rare, but due to the aging  process, its very common problem for the first generation 1UZFE cars.  This article is intended to rule out starter problem.  It&#;s much easier to change other parts associated with starter, than changing the starter itself.

The opposite side of the bypass plug is the back wire as marked in the picture.

Do you have any questions? If so, please head over to the forumsto get a quick answer or share your experience!

This is a freelance site with no support by huge companies.    I have taken extra steps to demonstrate in details how things are done.  Currently I am one of the few people doing Lexus V8 research and performance enhancement.  This effort comes from my personal love for this wonderful engine.  Most of the modifications are from trial and error. There's no cookbook for 1UZFE mods and its unknown territory for much of supercharger performance.  The parts, labor, web development and site hosting are % paid from my personal hobby money.  If you feel my efforts help you in any form, please do not hesitate to donate any amount of money to support this site. You have no idea how much I and the entire Lexus and Toyota community appreciate it!
Turbo Lexus IS300 Wont Start After Dyno Day. I broke it. :( Having wiring issues.

Lexus IS won&#;t start &#; causes and how to fix it

Lexus IS is a reliable road companion, but its a machine with hundreds of interconnected parts, and like any other machine it sometimes fail to deliver normal operation. In this article we go through most common causes of IS breakdown and how you can fix the problem.

The most common causes that hinders normal starting operation of your Lexus IS are dead key fob battery, dead 12v battery, corrosion on battery terminals, bad alternator, clogged fuel filter, broken starter, blown fuse, empty gas tank, immobilizer error or any fault in the electrical system.

1. Weak Battery

If your IS&#;s engine won&#;t crank or cranks very slowly, then the most likely culprit is weak or dead 12v battery. Investigating more closely and doing a battery voltage test will clarify whether the starting problem is due to the battery. A test can be done to measure the voltage between the battery poles, check the acid level and assess the condition of the starter battery.

If a new car battery has been installed, the battery may not have yet reached its full capacity. There is nothing to worry about. A new battery only develops its full capacity over time.

Test 12v battery

The voltage of the battery on your Lexus IS can be measured precisely with a multimeter. Before the test, the multimeter is set to the voltage range of the battery and connected to its plus and minus poles. Successful testing of the car battery, i.e. checking the voltage, usually results in values ​​of approx. 12 to 13 volts. Values ​​above 14 or below volts require an expert assessment of the condition of the car battery. Because the battery may have a defect with these measured values ​​and must be replaced.

Jump start Lexus IS

If dead battery is the reason for the breakdown of your IS, you can easily jump start it using jumper cables and a healthy battery from another vehicle, or using a battery booster if available.

First connect red cable to the positive terminal of your IS&#;s dead battery, then to the positive terminal of donor battery. Next connect black cable to the negative terminal of donor battery, then to the bare metal in the engine bay of your IS Start the donor vehicle and then your IS Remove the cables in reverse order.

This image has an empty alt attribute; its file name is how-to-jump-start-car-illustration.png

2. Corrosion on battery

Corrosion on the contacts of your car battery leads to loss of contact and reduced current flow, which means that your engine can no longer start properly.

To know if your IS&#;s starting problems are from dirty battery contacts, you need to investigate them. If you lift the rubber covers over the two battery terminals, you can check the terminals for corrosion. If you discover white deposits or silvery-green deposits, but no further cracks or damage, you do not have to replace the battery, just clean it.

Clean battery corrosion

To clean the battery on your Lexus IS, you have to remove the pole cables first, which requires no special knowledge, just a little concentration, as the order is very important. First remove the black cable from the negative pole. If the pole clamp is very tight, you can open it with pliers. We advise against using metal pliers, but if you use them, you must make sure that you do not touch any other parts of the body. Next you can unplug the red positive pole cable. Once the battery has been removed from the circuit, you can start cleaning the corroded battery. After cleaning, reconnect the terminals.

3. Weak key fob battery

If your IS has push start/stop button, then its possible that your vehicle may not start due to weak key fob battery. Don&#;t worry, you can still start your vehicle &#; the battery is only used to send the signal for locking/unlocking. If the key fob battery is empty, the door no longer locks or unlocks at the push of a button. The doors must then be opened manually. The immobilizer is controlled by a passive transponder. Passive means, among other things, that the transponder in the key does not need its own power source.

How to start Lexus IS with dead key fob battery

If you have a model of IS which only has a key fob with start/stop button and no place to insert a key, then try placing your key fob as close to the start/stop button as you can and then start the vehicle. If it doesn&#;t work, then look in your vehicle&#;s operational manual for exact location of key fob placement, as it may vary depending on model.

Tip: You can try starting your IS with its second key. It will also rule out any other problem with the first key, for example, water damage.

4. Broken starter motor

A starter is a motor for starting the engine of your IS The average life of a starter motor is about , to , miles, and the life will be shortened if the engine is started more frequently. In any case, since the starter motor also has a limited life, it will break down after using the car for a long time, and if the starter motor breaks down, the engine will not start.

Symptom: When you turn the key to start the engine of your IS, you will hear a clicking sound, which is the sound of a bad starter motor. And if the starter motor does not work with a healthy battery, suspect a malfunction of the starter.

If the starter fails, it usually needs to be replaced with a new one.

Temporary fix for starter

If the engine does not start due to the starter, the engine may start if you turn the key while hitting the starter motor with something like a stick or metal tool. This workaround is effective when the parts inside the starter are stuck together or the gears are slightly out of alignment.

However, it is possible that the starter is nearing the end of its life, so it is recommended that you have it inspected at a dealer or maintenance shop.

5. Defective alternator

An alternator is a generator that produces electricity. If your IS&#;s alternator fails, it will not be able to produce electricity and the battery will not be able to charge. Therefore, even if you think that the cause of the engine not starting is a battery failure and replace the battery, the battery will soon run out and the engine will not start.

Alternators rarely break down. In particular, modern cars have improved performance, so it is said that they will last , to , miles. Still, it can break down depending on how you use it, and in the case of a used car, the alternator may be quite old. Don’t let your guard down.

If the alternator breaks down, it must be replaced with a new alternator.

6. Clogged fuel filter

The fuel filter of your IS does not wear out like a mechanical part, but it gets clogged by dirt and airborne particles and clogs over time. The permeability of the filter drops, and so does the fuel pressure. To a certain extent this doesn’t matter, but if the fuel filter is too dirty, the engine will no longer perform at full capacity and in some instance may not start at all. Cleaning is not possible, you can only change the filter.

7. Fuel pump failure

If your IS’s fuel pump fails, then the engine won’t start. The pump normally ensures that the necessary amount of fuel is passed from the tank to the injection system of the engine with sufficient pressure.

Before your fuel pump stops working, it usually becomes noticeable: if your car’s engine breaks down from time to time, the car is difficult to start, the engine jerks a little or the engine performance drops, you should have your pump checked.

Wear or contamination of the pump can be the reason for this. If the pump is leaking, a power contact is broken, a line or a pump lever is broken, the fuel pump is usually also noticeable before failure. You can have a defective fuel pump replaced in your workshop.

8. Blown fuse

In rare cases, a blown fuse could also be the culprit in the breakdown of your IS Check all fuses in the fuse box essential for starting the engine. But, be careful when lending a hand yourself to the fuse box! The box is under power and repairs or tests should always be done in a workshop.

9. Defective spark plugs

Without functioning spark plugs, the engine will not start. The spark plugs themselves are often not affected by a defect. Instead, plug connections on the ignition system come loose. If only one plug is actually loose, you can fix the problem yourself on site. If a spark plug has failed, it must be replaced in the workshop.

Rodent damage

Rodent damage can be another reason why your Lexus IS won’t start. The animals crawl under the vehicle and bite through cables and wires. In principle, this can affect all vehicle systems such as the fuel supply, the oil supply or the power supply.

The rodent damage can usually be seen quickly by looking into the engine compartment. The damage caused by the rodent bite can be repaired in the workshop. Be prepared for relatively high costs here.

Engine failure

Although very rare, but it can also be the cause of the breakdown of your IS If a vehicle has an engine failure, then nothing works anymore. It is not uncommon for the driver of a vehicle to be responsible for such damage. Typical causes include tearing of the timing belt, incorrect fueling, insufficient oil, hydrolock, overheating of the engine, or continuous driving in an excessive speed range.

Only an experienced mechanic can diagnose engine failure in a workshop.

Use OBD2 scanner for diagnosis

Since Lexus IS is equipped with on-board diagnostics (OBD), a fault diagnosis can provide initial indications of where the malfunction is located.

To begin troubleshooting, you must first connect the diagnostic tool to your IS The OBDII connector is usually located under the dashboard. With the wire connected, you should turn the ignition on. But be careful not to start the engine. Most diagnostic devices then ask for some information about the vehicle. It is important that you enter this % correctly, otherwise the result of the search may be falsified. In addition to the vehicle manufacturer and model, you usually also have to type in the engine and vehicle ID number. For exact troubleshooting, always check whether the information is correct.


There are many reasons why your IS may not start. When looking for the trigger, you should always start with the most obvious cause, the empty battery.

In any case, it is advisable for laypersons to call a breakdown service or a workshop. In the event of a defect, the latter can directly initiate the repair.

Posted in TroubleshootingTagged Lexus IS Guides, Lexus IS GuidesSours:

Wont start is300 lexus

IS Won't Start When Cold

Extreme weather can be very difficult on your Lexus IS  If there is an issue it often make itself known when conditions are at their worst.  When it&#;s extremely hot. it&#;s the cooling system that is put to the test.  In the winter, the vehicle won&#;t start when it is cold.  

There are a few different reasons that can cause this, but it&#;s usually your IS &#;s battery that can&#;t handle turning the engine when it&#;s cold.

It very well could be the cold weather that is keeping your IS from starting.  But, you don&#;t want to rule out that it&#;s just not starting, and it happens to be cold.  Check out Lexus IS Not Starting if this seems it may be an issue for you.


Lexus IS  Won&#;t Start Cold &#; Causes

Not Starting Cold Lexus IS

1. Battery Capacity Diminished

Far and away the number one reason that your IS won&#;t start in the cold is the battery.  A battery has two different ratings, cranking amps and cold cranking amps.  Cold cranking amps are the batteries ability to start turn the engine over when it is cold.

Battery capacity diminishes with time and use.  So it may have enough cranking capacity to start the vehicle when it is warm, but when it&#;s cold, it just isn&#;t enough to turn the engine over anymore.


2. Wrong Battery

If you happened to have purchased a battery when the weather was warm, and now less than a year later it&#;s not starting your IS , you may have purchased a battery that doesn&#;t have the cold cranking capacity that your car needs to get started.  

This often happens when you have a six cylinder model, and you get the battery for a four cylinder.  They don&#;t have quite enough capacity to turn over a heavier motor when it&#;s really cold.

How to Start Lexus IS in Cold Weather


3. Wrong Oil Viscosity

If you put a heavier oil in during the warmer months, it&#;s not as likely to keep your IS from starting.  But, in the winter, it&#;ll make itself known.  The heavier molecules in the thicker oil can keep the engine from turning over fast enough to start.  For instance, maybe you bought 10W when the manufacturer called for 5W


4. Water in Fuel Line

Condensation can build up in the gas tank as temperatures change.  If the condensation finds its way into your Lexus IS &#;s fuel line, it can freeze and leave the engine unable to turn over.  If the engine is cranking fast, as though the battery is fine, this is a definite possibility.


How to Start Your IS in the Cold

Here are some tried and true ways to start your car in the cold.  They are presented in a way that would help you troubleshoot a car that you may be sitting in right now in the order that makes most sense for getting you moving right away.  Most of the time it&#;s going to be a battery related issue, so that&#;s what we are focusing on.


1. Turn on All of the Accessories and Lights

This may sound counterintuitive when the battery isn&#;t working very well to begin with.  What you are trying to do is give your IS &#;s battery a little time to &#;wake up&#;.  Once you do that go ahead and turn the key to the &#;on&#; position, but don&#;t start the car for at least 10 seconds.  This gives the fuel pump plenty of time to prime the injectors.  Now, go ahead and try turning the engine over and see if it&#;ll start.


2. Warm the Battery

If you are at home, and aren&#;t in a rush, you can unhook the battery and take it inside.  This will allow it to heat up to a temperature that&#;ll get the electrons in it moving.  Leave it inside for a few hours.  This can really help it crank the car over.  Be careful handling the battery.


3. Jump Start

Jumping the IS will get it moving around again in no time.  Jump starting utilizes the power from another vehicles battery and alternator to charge your battery and help the vehicle start right there on the spot.  You don&#;t want to let the engine cool all the way down, as it probably won&#;t start on its own until it&#;s warm outside.


4. Replace the Battery

You can take the battery into the local parts store to have it tested.  That would be prudent before outright replacing it.  You should look up the cold cranking requirement for your particular IS &#;s engine and model year.

You want to get a battery that can handle at a minimum what the manufacturer recommends.  Cold cranking amps are a standard.  A battery must crank for 30 seconds at 0° with a minimum voltage in order to meet it.


Conclusion:  IS Won&#;t Start in the Cold

If any of the battery related issues ended up being the reason why your Lexus IS wouldn&#;t start, it&#;s time to replace the battery.  If it warms back up outside, you may get a few good starts out of it, but its days are numbered.

Categories Lexus IS Sours:
LEXUS No Start...2005 IS't

Lexus Won&#;t Start After Replacing or Disconnecting Battery

If your Lexus doesn’t turn on at all, meaning the lights don’t come on and the ignition doesn’t turn on, there is a good chance you connected the battery terminal backward, or you have a blown a fuse. Your Lexus won't start because of blown fuses. 

In this guide, we look at common problems that will prevent a Lexus from starting after replacing the battery or disconnecting the battery.


Lexus won't start after replacing the battery
  • Lexus won’t start after changing the battery.
  • Lexus won’t start after disconnecting the battery.
  • The security light comes on, won’t turn off.
  • The engine won’t turn over.
  • The alarm goes off when connecting the battery.

Common Causes

This list of the most common causes that will prevent your Lexus from starting after you disconnect or replace the battery. These problems may also affect Toyota vehicles. 

1. Immobilizer Activated

lexus won't start due to immobilizer enabled

The most likely reason your Lexus is not starting after you change the battery is that the security/immobilizer / anti-theft feature disabled the engine start. 

Possible Solution

  1. Get out of the vehicle. 
  2. Lock the car with the key fob or lock the driver’s door with the key.
  3.  Leave the vehicle parked for at least 5 minutes. 
  4. Press unlock on the keyfob to unlock the car.  Don’t open any doors yet. 
  5. Remove the emergency key from the key fob and lock/unlock the driver’s door three times. 
  6. Now enter the vehicle and start the engine. If your car has Start/Stop button, press the button with your keyfob, not your finger. 

This will, in most cases, reset the immobilizer. If this procedure doesn’t work, it may be time for you need to take your Lexus to the dealer or local auto repair garage.

The alarm may or may not go off as soon as you reconnect the battery. The security light on the dashboard stays on or may flash. 

2. Key Not Recognized

Lexus will not start because key is not detected

Your Lexus may not start after changing the battery or disconnecting it has lost synchronization between the key and the vehicle. 

Possible Solution

start lexus after replacing battery

Instead of stating the vehicle by pressing the Start/Stop button, take the keyfob and press the Start button with the keyfob. 

3. Loose Battery Terminal

loose battery terminal

The battery terminal may be loose. A loose battery terminal will allow the car lights, ignition, and instrument cluster to turn on, but a weak connection at the battery post won’t allow you to start the engine. You may hear a click or two, but that is it. 

Possible Solution

To fix this problem, check the battery cables to make sure they are not loose. Use a 10mm wrench to faster the terminal nut.

Make sure the battery terminal clamp is tight and does not rotate on the post. If needed, clean the battery terminals with a battery brush. 

4. Battery Connected Backwards

lexus won't start after connecting battery backwards

Connecting the battery backward will also prevent you from the start of the car.

The red cable needs to be connected to the battery post with the + next to it. The black cable needs to be connected to the battery post with the (-) symbol next.  

If you install the battery backward, the car will be completely dead, and the lights will not turn on at all.

Connecting the battery backward will blow one of the larger ampere fuses or the fusible link.

Possible Solution

Lexus won't start due to blown fuse

To start your Lexus again, you will need to check all the fuses and replace fuses that have blown.

Check all the fuses in all fuse panels. Typically most Lexuses have three fuse panels—two under the dashboard and one in the engine bay. 

The larger fuses are not always located in the fuse panel, so check your Lexus wiring diagram to determine where the 30A, 40, 50A, A fuses are located depending on the model. Check all the fuses and especially the main fuses, starter, solenoid fuse, and alternator fuses. 

If all the fuses are good, there is a small chance the Engine Control Unit (ECU) may have been damaged when connecting the battery backward. See your Lexus dealer or a local auto repair shop near you. 

5. Aftermarket Alarm

Lexus won't start due to aftermarket alarm

If your Lexus has an aftermarket alarm or remote start, it may be reset, disabling the engine to start on your car. 

Check if you have an aftermarket alarm and if you do, find out who the manufacturer is and call them up. 

Your Lexus may not start after you disconnect the battery for many reasons, as listed above. Also, make sure the battery is fully charged.  Other possible issues include a bad brake light switch, fuel pump, bad ignition switch, starter relay, etc. 

Unless you are familiar with troubleshooting car problems, it may be wise to tow your car to a mechanic or Lexus dealer to have them troubleshoot the problem further. 


Now discussing:

Lexus IS cranks but does not start

  • , MILES
I was driving my lexus is on the free way and it jus died out on me. I have spark and the fuel pump is working. It cranks but will not turn over. Please help!
have the same problem?
Thursday, October 20th, AT AM

**Cranks but no start condition:

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem,Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if so, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.
Thursday, October 27th, AT AM

902 903 904 905 906