Can the car dealership retrieve a code once the check engine light is off? My car would not start so we thought it was the battery. Replaced battery still would not start. Called AAA to tow car to dealership. He got it started but still towed it. The dealer said they could not find the code because check engine light was off.
If there are no fault codes stored then there are no faults codes, it doesn’t matter that the check engine light is off.
Your car had a dead battery, when you replaced it you probably had the security system out of sync. You would have needed to switch off the ignition, close the doors, lock and unlock them. Then the ignition will function properly again. I have seen others towed in for this reason.
I have a related question. Can codes be “wiped” from a vehicle’s memory, or once they have been recorded, do they always reside someplace as a log that cannot be “wiped.?” Of course, I mean after the issue that caused the code has been resolved.
When a type A code is set, the computer will store a history code. So with the proper scanner history codes can be retrieved even if the Check Engine light is off.
However, if the battery is disconnected or goes completely dead, the history codes are erased.