For the past several months my 99 Camry has had a reoccuring issue. From time to time, with no predictability based on weather, speed, time of day, the spedometer goes to zero even when I’m pushing the gas. The check engine light then goes on and after a few seconds, the spedometer starts working again, though with the engine light still on. I have tried taking it to several repair shops and usually within a couple of blocks of the shop, the light turns off and I am told that since the light is off, the diagnostic will come back clean and nothing can be done. I am getting frustrated and concerned that my car is no longer safe to drive but I can not seem to get it fixed. Any suggestions?
Even though the light turns off, the system should still have a code (or more) stored. Head to your local Autozone, Advanced auto parts, O’Reilly’s, or whatever’s near you and ask them to read the computer codes for you. They’ll often give you a diagnosis, too (they want to sell you parts), but be sure and get the exact codes, then post them back here.
The light does not have to be on to read the stored codes.
I’m guessing the code thrown will relate to the vehicle speed sensor.
chaissos is only almost right about the code reading & the light being on or off.
Even after the light is off the codes will still be stored as “history” codes. Many code readers, including those often used at the auto parts stores won’t pick up history codes. At one of the places near me they won’t even come out from behind the desk unless tou assure them that the light is actually on. Call around to the local ap stores & shops and find one with a scanner that can do “history” codes.
Interesting…didn’t realize there was a special reader for that. I know my dealer can read them for me, for free, for both my VW and my Toyota. I normally go there, since they’re also the closest. Thanks, Cigroller.
Wow - a dealer that will pull codes for free? I want one of those!
I actually had an argument in an Autozone with the guy at the counter b/c I had, not history codes, but manufacturer-specific GM codes. These get set & stored as current codes, but they don’t turn on the check engine light. They are also not picked up by generic readers. I swore it was worth a shot to see if their readers would pick them up. He swore that if the light wasn’t on there weren’t any codes. I think I knew more than him, but that’s the way this store does things - no light on currently - no code reading will be done.
I have my own code reader & software now.
I think Shadowfax is correct about the speed sensor as the cause of the trouble. A faulty speed sensor will cause the CEL light to turn on and checking the code history will most likely verify it. Since the trouble appears to be intermittent there may just be a bad connection to it.