Incidentally, when a fault is detected and the CEL comes on, after the fault is repaired, or if it “self-corrects”, the CEL will automatically go out after three drive cycles with no further faults detected. Even though the light is out, as long as the ECM isn’t reset — e.g., by disconnecting the battery –the code is retained in memory for up to 40 drive cycles, and can still be read.
There’s a difference between the CEL flashing and the CEL on steady but other lights flashing. For example, whenever the CEL is turned on, the cruise control is disabled, thus the flashing cruise light. However, if the CEL is flashing, then that usually indicates a significant engine problem, such as misfiring, which can damage the catalytic converter or the engine itself. I’m not sure from the descriptions if the CEL was steady or flashing.
I’ve attached another wiring diagram for the starter system — this one is from the Engine system wiring diagram. It’s the same as the earlier one except that it shows the connection to the BIU. According to the FSM, that connection at the BIU is a digital data line for “immobilizer communication”. As noted on page 2-4ff of the Owners Manual, if the transponder in the key being used isn’t working, then the immobilizer can prevent the car from starting. How many keys does the owner have? If more than one (there should be three — two regular keys and one valet key — all of which can be used to operate the car), is it always the same one being used, or have all been tried?
