Toyota RAV4 Forums banner

Check Engine Light/VSC & 4WD lights explained

1M views 379 replies 153 participants last post by  rvshrinker 
#1 · (Edited)
Every time you start your RAV4, many of the warning lights on the instrument panel light up and then go out. This is part of a self-test to make sure that these important lights are functioning properly. But what happens when some of these lights DON'T turn off? What should you do if some of these lights come on while driving? Of course, in the case of the oil pressure or A/T Temp light you should stop the car before any serious damage is done. However, in the case of the Check Engine Light (CEL), there's no need to panic! The CEL is only telling you that the Engine Control Module (ECM) has detected a fault. It could be something simple, like a loose gas cap or it could be something more serious.

Generally speaking, there are 2 different groups of lights that show up. The first scenario is when the CEL, VSC, and 4WD (TRAC in 2WD models) lights come on. The second scenario is when you see the VSC, ABS, and BRAKE lights on. Sometimes the 4WD or TRAC lights also show up. So why do all these lights come on at the same time and what do they mean? Let's take a look at each of these scenarios:

1. CEL, VSC, and 4WD/TRAC (Check Engine Light, Vehicle Stability Control, and 4-Wheel Drive/Traction Control

The CEL indicates that the ECM has stored a diagnostic trouble code (DTC) and means something is not quite right in the engine. It could be any of a hundred different things such as a bad spark plug or coil causing a misfire to a bad oxygen (O2) sensor or yes, even a loose gas cap. Fortunately, the code can be read from the ECM with an OBDII tester and will usually point to the area of the problem and often to the specific part. But why would a CEL shut down the VSC or 4WD systems? Many of these features depend on the engine running at peak performance. The VSC for example, uses not only the braking system, but also controls the throttle to help get the RAV out of tricky situations. If the engine is not running right, the ECM shuts down those systems that would affected.

2. VSC, ABS (Antilock Braking System), BRAKE, and sometimes TRAC (skidding car icon)


This series of lights indicate a problem with the braking system. The BRAKE light by itself means either the parking brake is on or the brake fluid level is low in the reservoir. But when the BRAKE light is on with these other lights, it's an ABS failure of some sort. In the vast majority of cases, this is usually caused by a bad or dirty wheel speed sensor. These sensors look somewhat like a bolt with wires on one end. The speed sensors detect the wheel speeds and send appropriate signals to the skid control ECU. Speed sensor rotors have rows of alternating N and S magnetic poles, and their magnetic fields change as the rotors turn. The speed sensors detect those magnetic changes and send pulse signals to the skid control ECU.


The ECU monitors the wheel speeds through these pulse signals to control the ABS control system. But if there is snow/ice or mud on the sensor, it may not detect the pulse, and a code is set. HOWEVER, this code is not set in the ECM, it's set in the Skid Control ECU. Many code readers can't see these codes, because they're only designed to look for engine codes in the ECM. That's why a lot of people get frustrated when a mechanic or auto parts place tells them they have no codes even with 3 or 4 lights glowing on the dash! The wheel sensor isn't always the problem in this scenario--some owners have reported a problem with the brake pedal switch or a trailer wiring harness caused these lights to show up.

I went back through many of the old threads and compiled a listing of all the RAV4World users who reported these error lights. Out of the 41 users who had the first scenario with the CEL, 31% reported the cause as a bad or defective charcoal canister filter. A defective O2 or A/F sensor accounted for 24% of these reports. The infamous loose gas cap was attributed to 19% of the reports. As for the second scenario, I only found 8 reports and 63% of those turned out to be broken or defective wheel speed sensors. To view the listing which shows the user name, lights, codes, and eventual fix, download it here:

RAV4 Diagnostic Lights.pdf

Many thanks to fellow user RickL for compiling the list into a nice PDF for easy viewing.

Next, I'll show how to read and clear the diagnostic trouble codes with or without a code reader.
 
See less See more
2
#2 · (Edited)
If you have a CEL showing, the best way to read the code is with a good quality OBDII code reader. This device plugs into the diagnostic port under the dash near the hood release. It will read and display the codes that are stored in the ECM--these codes relate to engine and emission control system performance. The format for these codes is a P followed by up to 4 digits. For example, a P0031 code indicates a problem with the Oxygen (A/F) Sensor Heater Control Circuit, while a P0500 shows a malfunction in the VSS (vehicle speed sensor). While it is possible to read the CEL codes using the jumper method, it will only show a 2-digit code that doesn't correspond to the equivalent P code. If you don't have a code reader, many auto parts stores will let you borrow one or read the codes for you free of charge.

154371


However, if you have other warning lights showing without the CEL, most code readers can't display the codes because they are not stored in the ECM. But there is an easy way to read these codes by using the jumper method. All you need is a short piece of small gauge wire--speaker wire works fine, or even a paper clip bent into a U shape. With the ignition off, place the jumper wire across pins 4 and 13 of the diagnostic port.

154370


Now turn the key to ON, but don't start the engine. With the smart key system, push the button twice with your foot OFF the brake pedal. The warning lights should now be flashing on the instrument cluster. A light that is flashing regularly means that particular system is normal. A coded flash indicates a problem. For example, if the ABS light flashes 3 times, pauses, then flashes 4 times, that would be code 34--a problem with the Left Rear Wheel Speed Sensor. This corresponds with a code C0215 which is how a code reader would show it. In Toyota's documentation, they will show this code as C0215/34. Each of the other lights may be flashing a related code. In this example, you may see the CRUISE light flashing a code 69. This code shows a brake system malfunction because of the ABS problem. When one system sets a code, it often causes a domino effect which will trigger similar codes in other systems. When the root problem is corrected and the codes cleared, all the related codes should go away as well. As mentioned before, a CEL will indicate a code from the ECM, which will display with a P prefix, such as P0441. If you have a code reader that can read DTC's in the other systems, they will show up with a different letter. The VSC and ABS codes are stored in the Skid Control ECU and use the C prefix, such as C0278/11 which indicates a problem with the ABS Solenoid Relay Circuit. Still other codes start with a U such as U0122 (Communication Stop from VSC to ECM) which would show up as a flashing 82 on the CRUISE light.

So now that you have corrected the problem, by tightening the gas cap or replacing the O2 sensor, how can the codes be cleared? With a code reader you can use its clear codes function. Without a code reader, many people disconnect the battery for 1-2 minutes. But there is an easier way that doesn't require tools and won't affect your radio settings. Next to the battery is a fuse box. Open it and look for a 20 amp fuse labeled "EFI MAIN" and a 10 amp fuse labeled "ETCS". Pull both these fuses and wait a minute or two and plug them back in. The ECM codes should now be cleared and the lights off.



However, this procedure only clears the ECM codes. If you have ABS/VSC codes and lights, even disconnecting the battery will not clear them. To clear these codes from the Skid Control ECU, take your jumper wire and re-connect it to pins 4 and 13 of the diagnostic port. Now, turn on the ignition and immediately tap the brake pedal 8 or more times. You have to tap the brake pedal just enough to flash the brake lights 8 times and it has to be done within 5 seconds. Turn off the key, remove the jumper, and the lights and codes should be gone.

For a comprehensive list of all the ECM "P" codes, download this PDF:

ES-63.pdf

For the ABS/VSC "C" codes, download this PDF:

BC-62.pdf

Here is a brief explanation of the OBD-II protocols, compliance, and connectors:

OBD-II Overview


This document is a work in progress, and I will be adding to it from time to time. Any suggestions on how to make it better will be greatly appreciated!
 
#14 ·
How to Correspond Jumper method codes with P, B or C series code?

I have detected the code with a jumper method but I don't know to what code does it correspond. E.g my codes for 4WD are 82, 83 and for Traction are 51 & 98. I tried a lot searching in Google but did not find any code the way Toyota repair maintenance display (showing both code in one line).

Please help

If you have a CEL showing, the best way to read the code is with a good quality OBDII code reader. This device plugs into the diagnostic port under the dash near the hood release. It will read and display the codes that are stored in the ECM--these codes relate to engine and emission control system performance. The format for these codes is a P followed by up to 4 digits. For example, a P0031 code indicates a problem with the Oxygen (A/F) Sensor Heater Control Circuit, while a P0500 shows a malfunction in the VSS (vehicle speed sensor). While it is possible to read the CEL codes using the jumper method, it will only show a 2-digit code that doesn't correspond to the equivalent P code. If you don't have a code reader, many auto parts stores will let you borrow one or read the codes for you free of charge.
 
#3 ·
Check Engine / VSC / 4WD Lights are on!

It is my understanding the replacement of the charcoal canister is covered under the Federal Emissions Warranty > 8 / 80,000. Check your owner's manual. The codes are P043F, P043E, P2401, P2402, P2419. The TSB is dated 3-24-09. I am in the process of trying to get the local dealer to cover this. The problem is that after some time passes, more codes appear and in order to isolate these few, I have to have them read it right after the lights come back on after having been cleared. They are located in a different city, so it's not as easy as it sounds.
 
#4 ·
From the documents listed, I can't tell what all the codes I have mean. Here are the codes I have:

CEL = 14, 93
VSC = 51 = Engine Control System Malfunction - Engine control system
4WD = 82
Cruise = 69

I was able to determine the VSC code from document BC-62.pdf, but not the others. Where can I find those?
 
#6 ·
With the exception of the 93 (I got 94), these are the same codes I got from a loose gas cap.

Cruise 69 is "Brake system malfunction."
 
#9 ·
I have this situation described, with the CEL, VSC and TRAC lights on. Unfortunately, I have not been able to deal with it for quite a while. I just got the codes read, adn they were P0606, P0136 and P0136. The main point is that during the time the lights have been on, the engine performance has stayed the same. No performance loss at all. The gas mileage has stayed the same. The gas mileage has even gotten better since I put on new tires. I don't want to go on randomly replacing parts until the lights go away. How can I find out more details on these codes, especially the P0606. Thanks
 
#11 ·
Coil [letter] = cylinder [number]?

As a lot of the check engine light + VSC + 4WD incidents resulted in a diagnosed bad coil, I thought it was fitting to ask this here to provide future reference for other members.

Moderators please move this post if it was a bad assumption on my part.



When the trouble code reads:

P0352 - Ignition coil "B" primary/secondary circuit fault.

Does B mean cylinder 2? Do the letters correspond to cylinder numbers, as in A=1, B=2, C=3, D=4, E=5 and F=6?

I got the above code yesterday (on my 2006 V6 4WD with 61,000 miles) and wanted to make sure I replace the correct one.

Also, does the cylinder numbering scheme look correct below?

Firing order 1-2-3-4-5-6

Front --- 2 1
of ------ 4 3 --- Firewall
car ---- 6 5

Thanks in advance, folks!
 
#12 ·
I'm going to answer my own question here...

I replaced cylinder 2's coil this morning in accordance with the diagram I last posted. The check engine, VSC and 4WD lights cleared within 5 start-run cycles, 50 miles and 1 day. The coil was a Duralast part number C1601 from Autozone for $112.99, plus tax.

So for future reference: A=1, B=2, C=3, D=4, E=5 and F=6; and the cylinder numbering scheme from my last post was correct.

Coils 2, 4 and 6 are really easy to get to, but 1, 3 and 5 would be more work as they appear to be under the intake runners. My job today took literally 5 minutes.

I hope this helps someone someday.
 
#13 ·
Excellent Post. The "VSC, ABS, (!), TRAC" light combo has been coming on every few days or so. I recently had my vehicle undercoated (they use salt religiously here and undecoating is the only way to protect from rust), and I figured the stuff gummed up some sensors. Looks like the rear wheel sensors is likely the culprit. I figured they would have designed these vehicles to withstand significant snow/ice/undercoat build up, but I guess not!
 
#15 ·
JuneBug;877053 2. VSC said:
http://www.rav4world.com/forums/members/albums/32793-junebug1701/tech-stuff-2743-picture17696-traction-control-vehicle-stability-control-antilock-braking-system-brake-lights.jpg[/IMG]
Photo of dash lights matches my 2008 RAV4 to a T. From the pdf compilation, I'm thinking this is probably a wheel sensor. Do I need to take it to the dealership, or should I try something else first? Can I drive the car (to the dealer or otherwise), or is this probably an unsafe, call a tow truck situation?

Other probably irrelevant facts:
  1. No noticeable problems with brakes or steering.
  2. Yesterday I used the cigarette lighter to run an air compressor to fill my children's sports balls. I didn't turn the car on fully, and it took longer than I anticipated. I saw these lights when I next started the car. No apparent battery issues: starts right up. No apparent lighter issues: phone charges fine.
  3. One of said balls rolled under the left side of the car twice and slightly wedged itself in place. It did not appear to be moving fast enough to do any damage.
  4. We've just had two nights of hard freeze (upper 20s), our first of the season. The car is garaged, and the garage probably stayed in the 40s. When it was 30 outside, I measured the garage at 50 degrees. I mention this because I read of something similar happening when the temperatures dropped to teens.
  5. My son thinks he saw a mouse in the garage. Could a chewed wire explain this. (And ewwww. Critters seem to think it's OK to take refuge inside when it's really cold. I disagree.)
  6. I tried turning the car off and back on. No effect. I know, that would have been too easy.
  7. Tried the gas cap trick: started with cap off, turned off, started with cap on. That also would have been delightfully easy, and also had no effect.

Thanks so much for any help you can offer!
 
#17 ·
Photo of dash lights matches my 2008 RAV4 to a T. From the pdf compilation, I'm thinking this is probably a wheel sensor. Do I need to take it to the dealership, or should I try something else first? Can I drive the car (to the dealer or otherwise), or is this probably an unsafe, call a tow truck situation?

Thanks so much for any help you can offer!
No worries! All it really means is those functions most importantly ABS are hibernating.
These are what we call "run-to-the-dealer-&-pay" panic lights. Turning them off may be as simple as restarting the RAV. If there is a problem they'll come back.
At that point use the 4-13 jumper to read them then follow my advice on my last post.
 
#22 ·
What I've noticed is that even tho the codes remain the warning lights may go off at the next startup.
 
#24 ·
Well the lights came back on yesterday and cleared again today. It seems to clear right after I make a service appt. I'm taking it in next week anyway. I have noticed a sound coming from the front end that sounds very similar to my other cars when the wheel bearings went out. Sort of a metal rub sound. The sound has increased in volume over the last couple of weeks. I do have 152,000 miles so I would not be surprised if a wheel bearing is going out. They lasted twice as long as my non Toyota cars I current have. Could a wheel bearing cause the lights to come on and off, or maybe it's just two unrelated problems?
 
#25 ·
Could a wheel bearing cause the lights to come on and off, or maybe it's just two unrelated problems?
Yes, indirectly. Bad bearing causes misalignment or damage to the ABS sensor. You do know that if it's a non-CE light error (like an ABS code) you can read it with half a paperclip?
 
#27 ·
Got a weird one for you!

I get VSC, ABS & Brake error lights (and no others) as soon as I turn on the parking lights (on my way to turning on the headlights) with the key on, either engine running or not. :shrug:

They reset every time I turn the key off and back on. I get a 49 ABS code and a 43 VSC code. They remain until I reset them with the 4-13 jumper and the 8 brake pedal pushes.

It gets even weirder! There are two ways I can keep the three error light from coming on. Either turn on the parking or head lights on before turning the key on or, believe it or not, step on the brake pedal while turning the parking or head lights on! :shrug: :shrug: :shrug:

I thought it might have something to do with my battery so I swapped in my less-than-year-old Honda battery and put it on the charger. Same reaction! BTW, both the Toyota and Honda batteries performed identically in passing a toaster-tester load test.

Any ideas???
 
#28 ·
My guess would be either the stop light switch or the brake pedal load sensing switch. Do you have the codes associated with the lights?
 
#31 ·
It's under the dash near the hood release lever. Get down low, you'll see it.
 
#32 ·
Thank you for your post, it really is informative; any idea where is the speed sensor, how to find them? u say maybe they are dirty and I want to check them? thank you again
The speed sensor is on the transmission. If you're talking about the ABS sensors, there's one on each wheel. Remove the wheel and look for an electrical cable going to the sensor.
 
#34 ·
Hello everyone. First time poster here. I just purchased a used 2006 Rav4 V6 4wd with 100 000 km, and I absolutely love it!

We recently had a snowstorm here in Montreal, and I drove my Rav4 though some pretty deep snow on the way home from work. The following night, the temperature dropped to -20! Now I'm assuming the snow under my Rav4 froze. Today, I drove my Rav4 on the highway, and it was shaking at speeds over 55mph. I knew this was probably normal due to the imbalance caused by the frozen snow. I stopped to fill up gas, and then started driving on the highway again. All of a sudden at about 65 mph, my 4wd light, Check engine light, and VSC lights came on. I was worried, so I slowed down. Once I got off the highway and stopped at a light, the car was still shaking, even while stopped. Eventually I turned off the engine, and started it back up again, and the lights disappeared. The idle shaking also stopped. I drove it around the block a few times, and everything felt normal. However, I'm worried I might of damaged something while driving on the highway, due to the additional stress from the frozen snow under the car. A common problem with those lights seems to be the loose gas cap, therefore I'll check that in the morning. It is possible that the shaking caused the gas cap to loosen.

Do you guys think I should have it checked out at the dealer, or any ideas on what might of caused this issue?

Thanks!
 
#107 ·
Not that this adds much value, but:
Same thing happened to me, some snow was still in one of my wheels (did not see it when cleaning it all out), and @ 55 it was such a minor vibration I just thought it would ok. Well, I got on the freeway and I think the snow concentrated to one spot and all of a sudden it shook so hard I had to grip the wheel TIGHT! Anyways, all of my error lights flashed, I lost engine power and there was a constant surging back and forth. When I pulled over and stopped, it felt like the transmission was trying to shift all over the place, even when I put it in park it was still clunking/shaking bad. I shut it off right away and waited a minute and turned it back on and all the lights reset and I drove away with no problems. Not sure exactly what happened mechanically, but I doubt it was good for it.
 
#35 ·
JPL, it's probably not what's under the RAV, it's the snow and ice on the wheels that cause the imbalance and shaking. Also remember that there are ABS sensors on each wheel that can get accumulations of dirt, debris, and yes, even ice that can cause malfunctions.
 
#36 ·
You can add me to the list. 2008 RAV4 V6 AWD Base. 78000 km.
The CEL, VSC, and 4WD lights came on, and my Scangauge II reported a P2195 code. I visited the Dealership and mentioned my Extended Warranty. They had to remove the exhaust manifold in order to replace the seized A/F sensor. Parts replaced were as follows:
1 89467 - 0R020 A/F Ratio sensor
1 90917 - 06078 Exhaust gasket
2 90501 - A0005 Springs
2 90080 - 10291 Bolts

Diagnosis - $75.00
Hours 3.7 at $94 - $347.80
Parts - ???

MY COST - $0.00
I'm not sure whether this was covered by the extended warranty or the emissions warranty, but I'm a happy camper!
 
#37 ·
That's great! The parts add almost another $200 at their list price:

89467 - 0R020 $168.37
90917 - 06078 $9.34
90501 - A0005 $9.26
90080 - 10291 $8.68

Total parts $195.65

Without the warranty, this repair would have cost you $618.45!
 
#41 ·
Ok, I took it in today and they said they found a mass air flow range performance malfunction and found that I have the K&N intake. They recommended that I return it to stock. Well, I've had this on for 70 or 80,000 miles now and no real problems. The lights have been off for awhile. I think I'll give it a good cleaning.

As far as the metal rubbing sound, they said it the rear diff making noise. It's a slight sound. I told them it sounds like it is coming from the front of the RAV4 like wheel bearings. They said it's more towards the center. They recommended it be replaced at $1720.00 parts and labor. I think I'll wait until it gets worse.

The RAV4 is at 152,000 miles right now.
 
#43 ·
I am having the same problem only it happens every time I fill the tank with gas. So figured it had to be gas cap, I would clear the CEL VSC and TRAC lights by turning the key to Acc (just before turning it over) and hold in the trip meter knob for about 4 seconds and the lights would clear. this happen 3 times in the last 2 months The last time (4th time) the lights went out and then came back on the following day. And now the wont go out, I will try a new gas cap and see if they go off by holding in the trip meter as before. The car runs fine and I hate to take it to the Dealer if the lights wont go out after trying a new cap.

I am under a Certified Toyota Warranty but it is so difficult to know what they will cover. I am trying to find a Scanner to get the codes, before going to Toyota. ANY IDEAS?
Chris
 
#45 ·
CEL,VSC,4WD Warning lights

These came on. The dealer found a hose going to the charcoal cannister had ripped out/has a broken fitting. They want to replace the charcoal cannister and hose with air pump. Parts cost $843.00!

Does anyone know of a cheaper source. I can put the parts in or my friend with the service garage can.

Where do I find an illustration of the emissions system along with part #s. New to forum, I'll do some more looking. It may be there.

TIA
 
#46 ·
These came on. The dealer found a hose going to the charcoal cannister had ripped out/has a broken fitting. They want to replace the charcoal cannister and hose with air pump. Parts cost $843.00!

Does anyone know of a cheaper source. I can put the parts in or my friend with the service garage can.

Where do I find an illustration of the emissions system along with part #s. New to forum, I'll do some more looking. It may be there.

TIA
Check this;
http://www.rav4world.com/forums/99-4-3-mechanical/88159-need-new-vapor-canister.html
 
#49 ·
Wow thanks for the thread, this bit me too!

3 lights came on morning after check-up. Opened the hood to take off the MAF sensor to try and clean it and discovered that smaller hose between air filter and engine (EGR?) was not connected. That's the most direct "air gets in behind MAF filter" imaginable! Clearly mechanic forgot to reconnect it after changing the air filter.

Lights are still on though, will prolly take a few rides to disappear.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top