Check engine light going on and off


#1

I bought a 2002 Nissan Quest from a private seller and the check engine light came on 2 weeks after the purchase. It was running normally, so I took it to AutoZone. The code said “reprogram engine control module.” Over the next week, a few weird things happened - like the windshield wipers coming on (while turned off) or the battery light coming on for a few minutes then going off again. The check engine light then went off and stayed off for about a week before it came on again.
I took it to the shop I normally use and they said that the car was misfiring on one cylinder and some issue with the oxygen sensor. When I mentioned the code at Auto Zone, I was told “that code doesn’t exist.” ???
I was quoted $1400 for the repair which is out of the question because 1) I’m poor and 2) the car is only worth about that much. That was last week. This morning when I started it, the check engine light had turned off again.
My questions (aside from WTF is going on) are does a “reprogram ecm” code exist and do the issues I’ve been having seem typical of that problem?


#2

If you Google “Nissan OBD II codes”, you should be able to find a list of all the codes that can be generated. I don’t know if a “reprogram engine control module” code exists or not.

If I were in your position, I think I’d disconnect the battery cables tonight. Clean the cables and battery terminals where they connect. Then hook them back up in the morning. This will clear the codes and reset the computer (engine control module). If/when the check engine light comes back on, have it read at one of the parts stores. Ask them what the actual code is. It will be something like “P0030”. You can then look that code up and see if it’s a misfire code, etc.

From your description of the battery light coming on, it’s possible your battery connections are loose or corroded, which could cause the computer to possibly throw all sorts of codes.

So, clear the codes by disconnecting the battery, make sure the battery connections are good when you reattach the cables, then see what codes come back and go from there.


#3

there is a generic error code for ecm (P0602). Perhaps that is what Autozone referred to. I don’t if NIssan uses this code.

What kind of repair did they quote you to perform for $1400?


#4

Thanks for the responses!

The repairs were a tune up ($550) and the rest was something to do with the oxygen sensors, but I couldn’t tell you exactly what unfortunately. I tuned out a little after hearing the $1400. :confused: