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Toyota Sienna Warning Lights & Problem Codes



  • ateixeiraateixeira Posts: 72,587
    Glad to hear it. :shades:
  • Can you please tell me what they found with your Sienna? I recently had the same thing happen and I am being told from the dealership that my tires are causing the problems and that I need to replace them all.
  • atwb1atwb1 Posts: 1
    We have had our speedo jump back and forth and the car slows down like in first gear. Also check engine, ABS and brake lights in dash stay on. What can cause these to happen?
  • ateixeiraateixeira Posts: 72,587
    Do you have an OBDII scanner? I would try to find out what code is being thrown. With that many warning lights it could be electrical.
  • Perhaps take a look at the following link for more details:
  • I have a 2004 Sienna with higher mileage (248,000). I have been having an issue with CEL coming on. It only comes on after the car idles for at least 10 minutes. The codes are always the same P0171 and P0174 system too lean bank 1 & 2. I have a code reader that I can reset the codes with. The CEL will not come back on for over 1000 miles-provided I do not let the van idle. My mechanic friend suggested I clean the MAF which I did-no improvement. He then suggested that I change this part out-which I also did with a rebuilt part. It seems like the CEL takes a little longer to light-but it still comes on after any extended idle time. The CEL never lights when driving -only at idle.

    I have seen suggestions that the coolant temp sensor may be causing this. I have also heard that a clogged fuel filter may exhibit these same symptoms.

    Before I venture any further with replacing parts in search of a cure I would like to hear from the fine members here.

    Thanks in advance.
  • I have a really frustrating situation. My 2002 Toyota Sienna won't pass inspection.
    Several weeks ago, I had a check engine light come on before the inspection that showed I needed a new air sensor near the cat. conv.
    Okay, that was replaced two weeks ago. Since then, no more lights show on my dash.
    The mechanic said that his shop computer still shows my car won't clear.
    He initially said, two weeks ago, that "driving it" was a remedy for this. Well, I've since driven several hundred miles, and though my dashboard check engine light remains off (I'm not showing any lights anymore at all.)....the inspection computer still won't apparently clear.

    What do I do? Even the mechanic has no clue what I should do next. Drive it some more and bring it back again? I've done this twice now, and after several hundred miles, still, though no check engine lights are showing, I can't get my Sienna inspected in N.Y. State. Meanwhile, I'm driving with an expired inspection. I'm real sure that a policeman would believe I've tried my hardest to inspect this. Yeah, right.

    If even the mechanic doesn't know what I should do....then?...What?....Anyone who has any help or guidance on this would be greatly appreciated!

  • pjksrpjksr Posts: 111
    It's not the number of miles driven that will make your van ready for inspection. There are certain "drive patterns" that must be completed, for the ECU to test your catalyst operation, for example. Conditions that need to be met are for this one test: engine warmed up, drive 15 minutes, varying speed between 30 and 45mph. Do this twice.

    Without knowing which ECU monitors are not ready, I can't help you further. Your mechanic should be able to tell you, though. This is basic. Google "Sienna readiness monitor drive patterns."

    Good luck--hope you've already passed inspections.
  • The AC on my 2004 Sienna XLE stopped cooling. I ran the on board diagnostic function to display trouble codes for the climate control system. I received code 21. My Haynes Repair manual indicated that a 21 indicates trouble with the "solar sensor circuit". What is the solar sensor circuit? I also received a code 24. Haynes does not list a 24 trouble code. Any ideas on what's going on? Also how do I determine the low side service valve for the AC?
  • jjjjyipjjjjyip Posts: 2
    did yr mechanic check the oxygen and air fuel sensor? my 2004 sienna didn't pass inspection in 2009. i paid $2200 to fix it..... fixed the sliding door $2300 in 2010....they said the steering wheel has problem now.....i'm still thinking should fix it or not, it costs $2500..... what the "xxxk"sienna.......
  • bis1bis1 Posts: 2
    engine light came on,vsc and trac off lights came on too,i took it to the dealer toyota capistrano where i bougth it new now its 34000 miles in it,the whole day it sat there in the afternoon they said its done so i went home as soon i got out of the dealer the same lights came back again,so turn around and take it back inside the service yard they said they dint find the other problem they change one part but they said onother park needs to be change how come desame problem did they change the wrong part ? or they dint do anything,but i've heard once you reach 30000 miles this automatically come out evry 30000 and it just need to reset something whatsoever is that,thers no actually parts to be replace am i correct,pls give me information about this problem.
  • bis1bis1 Posts: 2
    is the gas cap has something to do with that damn indicator warning light what for or its just made like that so that they can drain money ,time,on the costumer it doesnt make sence a loose gas cap can do damage just like that they should correct this problem,whoever idea is that.
  • ouch2ouch2 Posts: 2
    I seemed to have a battery problem today, was able to get a boost and get started. However, I was unable to accelerate beyond 2000 rpm. The "check engine", "vsc", "trac off" lights came on. I tested the battery, replaced it, lights are still on, still no acceleration. Cannot drive over 25mph.

  • ouch2ouch2 Posts: 2
    I seemed to have a battery problem today, was able to get a boost and get started. However, I was unable to accelerate beyond 2000 rpm. The "check engine", "vsc", "trac off" lights came on. I tested the battery, replaced it, lights are still on, still no acceleration. Cannot drive over 25mph. This is a 2006 Sienna.

  • I have a 2004 Toyota Sienna Van with about 140,000 miles on it. My check engine light came on for about a week before I got it checked at a local repair shop while getting an oil change. Van was driving just fine. They pulled a code P0430 - catalyst system efficiency below threshold (bank 2). They had to order the part, so I have continued to drive it. Later that same day, the light went off. The mechanic says he did not reset the computer.

    My question is - when you get this code, how definite is it that the catalytic convertor is bad? How long can I wait to replace it? Fortunately, I went immediately to get an emission test done and the van passed. So I can get my tags with no problems next week. It is suspicious that the light went off on its own. I don't want to spend money on this if it is not necessary. But, I don't want to get stranded with kids in the van. The only thing I can think of that was different, is that I was overdue for an oil change. But, not enough overdue that the "maintence required" light came on.

    I would welcome any words of wisdom. Thank You!
  • I have a 2005 Sienna and on several trips usually on the freeway or highway to Las Vegas while traveling at higher than usual speeds for a time the check engine light has come on. Later on it went off after a few days of normal driving. I do not believe this has anything to do with the oil change schedule. When i get the oil changed at Walmart every 5,000 miles, I always remind them to zero out the maintenance light whether or not it has come on.
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,780
    edited October 2011
    The maintenance reminder system and the engine light (part of the OBDII system) are totally separate. The reminder system is on time & mileage, On Board Diagnostics is the federally mandated emission controls watchdog that monitors systems to ensure a clean exhaust.

    So, on to your code... The code you logged was from a reading by the rear oxygen sensor, located behind the catalytic converter. While the front O2 sensor plays a real feedback role in regulating mixture, the rear sensor is just a tattletale device ratting you out to the EPA as a person of low moral character (just kidding...). It is suggesting that there is a real problem, but in no way impacts driveability, emissions, etc. If it wasn't that many states will not grant inspection stickers if this is a hard code, you could drive on forever with perhaps minimal impact, other than a sooty exhaust.

    Now in reality, continuing to drive this way could eventually result in a clogged cat, which could degrade performance. So you do want to know why, and get it fixed.

    Why did the light go out? Your system has several 'tiers' of code notation, ranging from "something happened, but it might just be an aberration", all the way up to "DEFCON 5" Armegeddon.

    "Something happened" codes can go away in as little as 3 'drive cycles' (basically cold starts with some driving). More severe but fixed items go away after 40 cycles.

    Sounds like your rear sensor might have sniffed out a one time burst of rich mixture, and it went away. Time will tell if it will return. Summer/Winter crossovers are common times for this to happen, as gasoline is 'reformulated'. Long drives with one pedal position & constant speed followed by a sudden off ramp (a big change in system status) have been known to trigger it on marginal systems.

    Proper diagnosis can be difficult but it is essential. It could be a degrading cat, a dirty or compromised O2 sensor, bad wires or connections, or a computer issue. If you don't know what is broken, fixing it can be very costly!

    And that concludes tonight's lesson!
  • Hi, I'm habving the exact same problem with my 2011 sienna. Did you find out what was wrong and how to fix it? I called the dealer and they weren't much help at all. The mechanic i talked to never heard of this happening before. aahhhrrgg. take care. :cry:
  • joedinhjoedinh Posts: 2
    edited October 2012
    you seem to have the same i had recently ( i have the same car you have). i brought to toyota services and all theyb did is charged me a stupid over $400 and only changed a fuse on ETC( electrical throttle control ) and some others sunnessesary . do not make mistake like me.

    good luck
  • i have toyota sienna 2006 with code p0430 ,i cleared it,repplaced it and came back on again after driving about 200 miles. I cleared it again it go on again after about 20 miles , i cleared i again and again. At one time the check engine light went off by itself without cleared . Any suggestion ,thank you very much.
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,780
    To clarify, you changed the front catalytic converter? Did you also change the lower oxygen sensor?
  • Hello, Thank you for posting your experience with the 2004 Toyota Sienna ABS and Sensor issue! I know it has been a while... I just ran into this today, got the exact same answer from the toyota service as you got... and was wondering if the solution you have posted lasted, or any issues came back later... thank you for the info you posted! Looks like it could help quite a few people avoid spending major $$$ on an unnecessary repair!
  • I have a 2009 Sienna and it has happened twice for very brief periods. I will be driving along at highway speeds for extended periods and get an alarm. It is a beeping at about 2x per second accompanied a flashing indicator in the upper right portion of the dash near the maint req light. This was so brief (2-3 sec each occurrence) that I couldn't determine what exactly the light was that was blinking. Has anyone else experienced this and what was the problem/solution?
  • ckgrickckgrick Posts: 6
    I've had numerous issues with my 2006 Sienna with only 21k on it. One has been erroneous warning lights. This morning another incident with the Check Engine-VSC-Trac warning lights suddenly coming on and staying on even after a few starts and stops.

    Based on past experience I first check the internet for fellow sufferers to see if there isn’t a simple fix and an avoidance of the dealer. Sure enough this is yet another common issue. A loose gas or defective gas cap seems to be a common problem. Checked, but not my problem.
    Next seems to be a faulty oxygen sensor, e.g. dealer and money. After only 21k I didn’t think it was likely (or maybe it was hope it wasn’t likely).

    Third most common is a recent tire change affecting the ABS and thus the Check Engine and VSC Trac lights which activate evidently to protect the systems. I did have to replace the front tires already, but that was some time and miles ago, so I doubted that was my issue.

    Fourth, and way too common with Sienna’s, a faulty sensor reading. A solution to this possibility I found on – disconnect the negative terminal on the battery for a few minutes. The lights are now off.

    My Sienna is painted red; it should have been painted yellow for lemon.
  • shopteeseshopteese Posts: 1
    i have an 02 Sienna and the engine light came on, had it scaned and the code came up P1135. A Air/ Fuel sensor bank 1 sensor 1 . I purchased the sensor from Autozone, put it in and the service engine light is still on with the letters VSC and tractin off light on. Any helpful advise out there.
  • ckgrickckgrick Posts: 6
    You sound more expert than me, but my research on this issue indicates that it takes a while for the warning indicator to clear even after the issue has been resolved. Also the VSC and Trac Off always come on whenever the Engine light comes on as a precaution. Hopefully it will clear after a few on and off cycles.

    You could also force a clear by disconnecting the negative for a minute or so and if it doesn't return all's good. Mine is still off after many on and off cycles and a couple hundred miles.
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,780
    edited May 2013
    Unfortunately, part of your persistent problems may be related to your low annual mileage. Mechanical things and even electronic sensors 'like' to be used & cycled, and many short trips or days of sitting can have a negative impact.

    I highly advise you to buy a code reader with a clear/reset function, and use that instead of disconnecting the battery. Some of your problems may be directly related to this practice, and Toyota has advised against doing this in multiple publications. TT-0086-11 is one of the more recent ones that list recovery procedures from poor driveability after a battery disconnect. These vehicles rely on 'learning' and stored values to compensate for age and wear. When you wipe the memory, you reset to original factory specs, and the vehicle can really be at odds with these values. Doing this wipes out idle settings, short and long term fuel trim, ignition timing, etc. This can result in false oxygen sensor (front A/F and rear O2) codes, or even converter degradation.

    VSC & Trac *may* come on, depending on what the logged code is. It usually accompanies issues that impact driveability, and not necessarily just simple emissions issues.

    Some codes set on a single incident, some after failing several tests in a sequence. Codes can go away in as little as 3 passing drive cycles, some remain up to 40.

    I've not seen a code set just because of a tire change, although I suppose that earlier indirect TPMS could - especially if you have severely mismatched tires that result in a substantial rotational difference? I'd be interested to know more on this one.
  • ckgrickckgrick Posts: 6
    Some good advice. Thanks. I'll break down and get a code reader. Any recommendations?
  • fibber2fibber2 Mid Hudson Valley, NYPosts: 3,780
    I run with a laptop based system that is on the expensive side. I'm sure someone can chime in on their recent experience with a sub-$100 handheld unit. Sorry that I cannot be of help here.
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