Engine Light on 2000 Camry

I have a 2000 Toyota Camry. Several months back the ‘check engine’ light came on. I had it checked out at Auto Zone and they told me I needed a new sensor and thermostat. I took it to my local Toyota dealer and they said it was bad wiring to my rear lights. (Nothing was said about a bad sensor or thermostat.) I was skeptical but assumed they knew best what was wrong. I had them make the recommended repair ($283) and drove away. A few weeks later, the ‘check engine’ light came back on. This time I took it to a local garage. They said I needed a new sensor and thermostat.



My question is: Did I get wripped off by the Toyota dealer? Could bad wiring to my back lights have also caused the ‘check engine’ light to come on and why did their computer analysis not register the sensor and thermostat problem as well?



Candis in Memphis, TN

You may have gotten ripped off but it’s tough to tell. Wiring problems can play tricks. If a wire shorting to ground (or with a high resustance short) is in any way feeding off the same power bus at an emissions sensor, it can provide an easy path to ground and affect the power to the sensor, causing an erroneous signal.

My guess is that they found a bad wire, simply blamed everything on that 'cause they cleared the codes and they didn’t come back when they started the car, and sent you on your way.

So, in summary, you may have had a bad wire and still need a new sensor and a thermostat.

My question is: Did I get wripped off by the Toyota dealer?

Maybe sort of? They probably fixed a legitimate problem. Just not the one that brought you to their shop?

***Could bad wiring to my back lights have also caused the ‘check engine’ light to come on ***

Probably not. The Check Engine-DTC et al are primarily aimed at catching emission control problems. Your back lights are not a emission control subsystem. It’s remotely possible that a wiring problem might somehow “glitch” the computer, but my guess would be that if it did, it would also blow one or more fuses.

***and why did their computer analysis not register the sensor and thermostat problem as well? ***

Quien Sabe? Maybe the dealer shop made a mistake. Maybe the vehicle computer has faulty code and sometimes has a CEL light on with no stored codes. Maybe the analysis equipment has a bug. Maybe the codes are intermittent and “timed out” by pure chance while the car was at the dealers. i.e. You drive the car in with the CEL on and the codes in the computer. But the condition causing the codes hasn’t been seen for a while. When the dealer starts up the car to examine it, the computer says “Those codes are old, don’t need them anymore” and clears the CEL and codes". Mechanic sees CEL is off and no codes but notes that the rear lights aren’t right. Comes up with (implausible) theory that the wiring is causing the computer to misbehave. Could happen … I guess.

====

I must say that I have some doubts about the competence of a shop that thinks rear lights have something to do with a Check Engine Light. It’s remotely possible that Camrys have some peculiarity that makes that plausible. But that’s not how I would bet.

Greetings,
Thank you for your informative reply. I think you are so right in that the dealership (in their desire to generate revenue) repaired some bad wiring, reset my computer and sent me on my way not actually fixing the true problem. What I didn’t mention in my original question is they also listed 3 additional items on their repair list hoping to make this little trip worth over $2000. I did not have that kind of money so we just went for the most important issue. In addition to possible unwnecessary repairs, they didn’t even properly secure my new wiring back to the hing that holds my trunk lid on. As a result, I almost damaged my beautiful new wiring the first time I used my trunk. I’m afraid at this point I have very little confidence in my the Toyota dealership here and will be returning to my local garage in the future. I had thought about submitting a complaint to our BBB but it looks like my repairs ‘could’ have been warranted and if not,would be hard to prove other wise.

Again, thank you so much for taking the time to reply to my question. This is my first time to use this question & answer board and its nice to hear from someone more experienced than me in dealing with Camry repairs.

Candis in Memphis,TN