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Toyota Avalon Electrical Problems



  • tkaztkaz Posts: 69
    Mine come on when I approach the car with my fob when the car is locked. They will also come on if I hit the unlock button on the fob.
  • fmayberryfmayberry Posts: 33
    Does anyone have experience splicing into the electrical system of a 2005/2006 Avalon for trailer lights? Which power adapter did you use? Did you run a dedicated power line from the battery to power the lights? Where did you splice into the electrical system? Any other point or tips to be aware of? Thanks.
  • I have a 1999 XLS that recently had a dead battery which was surprising because it was new -- I charged it back up and a few days later went out to my car at 1am, and surprise, the headlights were on for no reason -- it explained the dead battery but does anyone know what is the reason the lights would come on randomly??? The selection on the turn signal is on off, not on auto and no key in the ignition.... any suggestions before I have a mechanic change $75 an hour with a min of 2 hours just to figure out the problem. Thanks in advance.
  • user777user777 Posts: 3,341
    an alternator which is possibly failing.
  • badgerfanbadgerfan Posts: 1,565
    Huh? How could a failing alternator cause headlights to go on when the car is parked and not running? Did you really read the post?

    More likely there is a fault in the electrical wiring, healight switch, ignition switch, etc that would cause this to happen.
  • user777user777 Posts: 3,341
    yes i read the post...and my post. ;)

    let's see, when the vehicle is running, power is being supplied by the alternator which maintains a charge on the battery. bad alternator, and eventually bad battery.

    now then, many cars are controlled by a miriade of computer systems. a poor voltage regulation section on the alternator may result in blowing headlights. ;) in addition voltage spikes might find there way over to the various computer systems, and as I'm sure you know, that may result in a computer system getting into a random state or actual damage to components. but yeah, you'd expect this to be an issue with the vehicle running. however, if the damage to the computer was done when the vehicle was running, it might exhibit itself later with the vehicle parked.

    but back to the battery, if it discharges below some threshold because of a bad alternator, yeah, i can imagine a program running errant. ever have a computerized kid toy go crazy when the batteries run down past some point?

    a marginal alternator isn't out of the question, so i thought the randomness and a failed (new) battery could be caused by a flakey alternator.

    ok, maybe it's something else. maybe a bad main computer, or maybe some parasitic load drawing the battery down when the vehicle is not running.

    i wonder how many more ideas will be generated by the readers of this forum to the problem...

    ok, i'll add another, a key FOB in someone's pants pocket or purse or in the hands of a little one.

    never did i claim to know the root cause, but the one i postulated is still a reasonable one given the limited information provided.


    yes, your ideas are also possible. nowhere did the poster ask for an exhaustive listing of possibilities.

    am i out of the dog house?
  • badgerfanbadgerfan Posts: 1,565
    You are out of the doghouse, but you might be overanalyzing this. Then again, with the increasing complexity designers have managed to complicate simple functions, you could be right

    Makes me glad headlights on our vehicles are only controlled by a simple headlight switch and no day/night automatic sensors, etc. The only interlock is it warns me if I open the driver door with them still on.

    Sometimes life is simpler when the driver alone controls the operation of the headlights!
  • wwestwwest Posts: 10,706
    Not random.....?

    On earlier Lexus versions if you stopped with the headlights on they would turn off automatically if you first turned off the ignition and then opened the drivers door. Open the drivers door first and the headlights would remain on forever....
  • user777user777 Posts: 3,341
    now that's funny.
  • kicker9kicker9 Posts: 57
    I have an 03 I'm trying to do the same thing with, I tried splicing in with the tail light bulbs but couldn't get the parking lights or the brakes lights to work properly, probably will have to take it to someone more knowledgeable and pay the fee.
  • kicker9kicker9 Posts: 57
    Follow up to trailer lights wiring, it turns out I wired my car properly, but, as it turned out, my New utility trailer had faulty wiring causing the lights to work improperly, new trailer, correct lighting.

    You will need a wiring harness with a built in convertor, available online for 25 bucks or so and wired as follows:

    There are 5 wires coming from the convertor that need to be wired to the car under the bulb access covers in the trunk,

    Yellow goes to the green/yellow wire of the LEFT rear turn signal bulb

    Green goes to the green/yellow wire of the RIGHT rear turn signal bulb

    Brown goes to the solid green wire of the LEFT rear brake/tail light bulb

    Red goes to the green/white wire also of the LEFT rear brake/tail light bulb

    White goes to a ground, you can use the nut and stud under the LEFT cover
  • abfischabfisch Posts: 591
    A couple of things I would like to add to this forum at this time. I have 83K on a 2002 Avalon XL. I have another car now that I use during the summer months, but use the Avalon for trailing, winter, and everyday useage.

    1. The blower motor makes a clicking sound and will not go to defrost any more. Sounds like the cheap teeth to the gear that turns the flap door is stripped. Another part I have to have someone replace requiring taking the dash apart. Not looking forward to this. Glad I have a third car.

    2. I kinda over did the towing and headed up the bearing in one of the axles, so I would think that the estimates the manufacurer gives is generous, and I would recommend trailing below the limit, not at the limit anymore. I trailed 2000lbs(a ton) back and forth from the nursery, and a front driver this old, just could not really take it. The new ones have half the tow rating, whoever is towing is not towing too much.

    3. I replaced the rear control arm bushing(had someone else do it) with quite remarkable results. I used Energy suspensions PU CAB set, and the rear of the car follows the front much more precisely without any transmission of more vibration. I run standard size 205/65-15 tires on the car. When things start getting worn, I would recommend these bushing over the OEM parts or the entire arms which sometimes they try to sell you.

  • jenshijenshi Posts: 6
    I bought my current car by this Jan. This is my first car. When it did the inspection, the car changed the new battary. but 2 months later, the car can't be started, the car was towed to repair center(it is also a gas station), i was told the the battary was not good and the charging system(i don't know car, so i don't know how to call it) who pass the electricity to battary didn't work for the battary, need to replace both of them, the cost was around $400. Because i don't the car, i don't know whether the car repair center ripped me off. this was my first car repair experience.
    This time my car has problem again, three lights (check, vsc and vsc off)on when i am driving the car. this time i did the search from internet before i went to the car repair center. First i went to the toyota dealer service, i just want to know what's wrong with my car, but i was told the diagnosis will charge me $220, it is too expensive. i went back home then went to another car repair center, they charged me $35 for the trouble code. the trouble code is p0171. The DTC detecting condition said: when air-fuel ratio feedback is stable after engine warming up. fuel trim is considerably in error on rich side. The guy told me: the trouble areas are 1)open or short in A/F sensor(bank1,2 sensor1) circuit 2/A/F sensor(bank1,2 sensor 1). so i need to buy two sensors, the sensor price from toyota dealer is $207 each, he said if i repair the car all from him, the total charge is $405(the parts also from toyota dealer,he said he will give me $187 each). sign, i am really bad luck, the car always give me trouble, like a momey eater.
    Now my questions are:
    1)does three lights on, and trouble code is p0171, show the problem what the guy told me, and i need to replace two sensors? or maybe any other problems? like air indcution system problem, if so ,is it a serious problem?
    2)if i don't repair it , will they hurt my car, and lead the big trouble later on?
    3)should i go to toyota dealer's service or the place i mentioned above. i know from dealer the repair cost is more expensive than other personal repair center. but i think the toyota dealer is more trustable, they won't do bad thing on my car?is my thought true?
    Thanks everybody here can help me, i am a female and i don't know about the car,i am the only driver in my family. so i really need your help me to tell me what i should do. thanks again.

  • bobwileybobwiley Posts: 241
    jennifer: First, how many miles on the car? How much did you pay for it? You'll have to fix the problem sooner or later (sooner better), get the problem fixed!!! 2000 Avalon's did have electrical problems according to Consumer Reports. Talked to my mechanic and he said---price is VERY fair. If no other codes--should be OK to go. You have to decide when "enough is enough" regarding repairs. Overall, 2000 Avalon's were VERY good cars. Good luck and let us know the outcome.
  • jenshijenshi Posts: 6
    thanks Bob, when i bought this car, the mileages already 97990miles, it costs me around 10K(including tax,i am in ny). my neighbour tole me it is a deal. i am just doubt whether it is a deal or not, since it gives me so many troubles. the car still hasn't been repaired, since i am searching the possible problem, sign, it is very hard for a female who doesn't know anything about the car. i searched the same problem as mine car, said possible need to clean the MAF sensor. i am trying to do myself to take it off and clean it, but i don't know where it is located, the guy who printed the trouble code for me didn't like to show me, i know he wants me to repair the car from him. But i am just worried about he knows me i don't know anything about the car, he may rip me off. i really hate my first car repair experience, because my neighbour told me the guy must rip me off. i feel so helpless, because no one really can help me except i go to the dealer who i may trust.
  • bobwileybobwiley Posts: 241
    jenshi: Do you have a Firestone/Goodyear/Pep Boys near you? they are all very reputible repair places and their prices are well within the acceptible range as they use standard "Shop Hourly Rate Charge" in computing repair costs. As I said before, our mechanic said the price you were quoted is VERY fair. The yearly mileage on your 2000 figures to be about 14.000 (98,000 miles divided by 7 years old), and 98,000 miles on an Avy is nothing. Our friends just sold their 95 Avalon with 170,000 miles on it for $3,900 and it runs like new. I know how frustrating it can be when ya feel like nobody cares or their just trying to rip ya off. I'd recommend fixing the car---afterall, it is mechanical and electrical and things do go wrong. Good luck!
  • jenshijenshi Posts: 6
    thanks again, Bob, ur input is very important to me. i do find the Firestone/pep boys around my home. my question is: do they charge the same hour rate as Toyota dealer? Because toyota dealer is near my home,just 5 blocks, if the price is same, i would go to dealer service, but if they are cheaper than dealer, i still like to drive there to get the car repaired. i want to find a place that it has good reputation and the price also reasonable and afforable. the guy told me to repair my car, the parts must be bought from toyota dealer, otherwise will still give trouble.
  • bobwileybobwiley Posts: 241
    jenshi: It is true--most parts for a Toyota must be bought from the dealer. However, my mechanic gets the oil filter for my 06 Avy Ltd for $6----not sure from where--Don't ask--Don't Tell!! Call Pep Boys/Firestone--you know what needs to be done--they can at least give you a quote. I'd probably go to the dealer--only 5 blocks away--also,, ya know he's close if it ain't fixed right!! I've been very fortunate to locate an HONEST mechanic--fair pricing and if i need "emergncy" work--because he services my Avy and wife's Jeep, we get priorty attention. Good luck and let us know the results!
  • jenshijenshi Posts: 6
    i went to the another store to diagonose my car. the guy just help me to shut off the three lights. he said, the lights may or may not comes back,if come back, he will repair it. he think it is the TPS -truck control sensor is bad. and i asked him to write down the trouble code for me, a lot of trouble codes: p0172, p0120,p0121,p0715 and p1128. obviously, i went to two stores and got the different results. the first one only said the trouble code was p0171, nothing else. i don't know who i should trust. the second one also suggested me do a lot of turn-up:
    1, spurk plugs 2, wires, 3,air filter,4 gas filter,5 pcv valve 6,clean the trotle. i just let him replace the air filter, others i am not sure whether should do or not. i know most of techinicians let ur replace here and replace there.
    here i need ur help:
    1.what all these trouble code mean,p0172, p0120,p0121,p0715 and p1128?
    2. how much is the TPS -truck control?
    3. should i just follow them to do what they suggest me?

    sign, my car didn't get repaired, but i already spend $80 for the two diagonosis.
    your inputs is very important to me, thanks.
  • user777user777 Posts: 3,341
    the TPS is the throttle position sensor. it tells the engine control unit (ECU) how much air (and thus fuel) is being commanded for the engine because the TPS measures the position of the throttle valve.

    cars are supposed to run to a specific Fuel/Air ratio. the throttle is the valve that lets the engine suck more or less air comming from the air intake and filter.

    your car's engine is essentially an air pump. it does it's work based on the compression and expansion of that air (in unison with fuel and spark) to mechanically move the pistons and apply torque to the drive train connected to the engine.

    When the throttle valve commands more air, the vehicle needs to add more fuel via the injectors to keep the F/A ratio within certain limits, but also to add power.

    for the trouble codes, why don't you google each one of them? you can do it.
  • bobwileybobwiley Posts: 241
    jenshi: Stop wasting your time and go to a Toyota dealer--must be one or two in your area. They (should) know the car and early Avalon's were fairly bulletproof cars. Good luck!
  • I am actually having this problem right now with my 2002 XLS. It just started yesterday and is irritating me. A lot.

    All of the electrical systems work fine. I can turn on the headlights and play the radio etc., but when I turn on the ignition, everything dies. If I open the hood, then shut it again, the lights come back on. Sometimes, the car will start and be fine. Sometimes the dashboard doesn't work at all but the climate control and radio will work. It seems that there is some issue with the engine immobilizer. Could this be an issue with a fuse or is the compter going wonky?
  • It sounds very much like you have corroded terminals in either your battery or the cables and clamps connecting them. Check them out thoroughly, I'll bet you dollars to doughnuts that this is the case. Once you find the corroded terminal(s), your problem should be solved.

  • I checked the termninals and the cables and there isn't any corrosion. I started the car last afternoon about 15 times in a row and it started fine and all of the systems were working. However the dashboard data was all reset (January 1st, compass pointing the wrong direction, etc...).

    I guess it's time to take it in. Thanks for your help.
  • Hello wseattle78,

    My mother had this same problem with her 99 Avalon XLS. In Canada they came with automatic headlights. It says in her owners manual to turn the headlights to the off position, as to extend battery life, as the sensor can drain power when the car is off. On a side note in her case it turned to be that the keyfob is open the trunk after a very light press. (future Avalons require you to hold the trunk open option for several seconds) The light in the trunk is a simple loop from battery to trunk switch to trunk lamp to ground, with no light in the dash to indicate its opening. The lamps draws alot of power and caused her to run down 3 batterys before I trouble shot the problem. (we live 2000km apart) Installed an LED trunk light that drew less power and her problems were solved($12.00). Also if you find that that helps I can provide info to install an inline LED to the trunk lamp circuit so it lights up in the dash cluster to indicate the trunk is open.

    Sorry for the winded reply,

  • jenshijenshi Posts: 6
    the three light was turned down two month ago, now three light is on again. so i have to repair it at no choice. today i went to the dealer first, i just want to know the retailer price. the guy told me the TPS is THROTTLE POSITION SENSOR $75, and not the technician said truck control sensor, but the technician told me TPS will cost around $400. so i want to know does anybody here know about truck control sensor, or the technician gave me the wrong name? and does someone here know how much the TPS, I just want to make sure the guy gave me the right price for my 2000 avalon. thanks a lot.
  • jenshijenshi Posts: 6
    three lights are checking engine light, vsc, and vsc off .
  • Traction control off light comes on when car is running.
    ABS is off.Trac on /off switch is O.K. What might make this light stay on?
  • abfischabfisch Posts: 591

    My washer pump is not working. 86K on 02 car. Wipers work so it is not the fuse (25A). Pump located underneath car. Can someone go through how to do it yourself if they have before. If not, I will do it myself on Saturday. No way to access pump from engine bay. Toyota wanted $60, Advance Auto $33, and NAPA $26.

  • did you figure out why the light comes on? my avalon is doing the same thing.
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