QuestionQUESTION: Hi Roland, Just like to say, your wisdom has helped me through most every problem I have had with this car! Thanks! Anyway, went to leave for work today, and the car turns over but will not start. I replaced the ignition switch last winter, so I wouldnt think it is that. What bothers me is that, I have had the check engine light on for awhile, and the codes read for basically a bad ground, and would go off and back on while driving, I think it was code 12, today I get no codes at all when I do the off on off on off on, yet it just keeps turning over. The check engine light doesnt even go on when I turn the key forward???? I am stumped!
ANSWER: Hi Ken,
The code 12 and the lack of a check engine light leads me to suspect that one or the other of the battery supply circuits to the engine control module are not connected. The code 12-related
wire is red/white and it comes from the power box under the hood from fuse B (20 amp) which is the next to rearmost fuse of the inboard row of 5 fuses. So verify that both sides of that fuse show 12V and/or look at the fuse closely for a subtle crack if not a frank blowout. It is connected to pin 3 of the pcm. The ignition switch provides the other power circuit thru fuse 18 (10 amp) in the fuse box behind the dash (remove access to check that fuse, similarly). It connects to pin 9 of the pcm via a dark blue/white wire. Once you get the check engine light back 'on' the engine may start or at least you can get any fault codes.
Thanks for the kind words on previous problmes. You are welcome.
Roland
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QUESTION: Ok, checked both fuses, both are fine. Upon checking voltage, one side(left if facing front of car) shows 10 to 12 volts the other shows 0.
ANSWER: If you are speaking of fuse B then that indicates the fuse isn't conducting, probably has a crack in the wire you can't see.
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QUESTION: Hello, ignore my last post!! Voltage is good through fuse, just to be safe, I ran up the street and grabbed a new one, so thats not it.
AnswerHow about the other fuse and also check for voltage at pins 3 (all the time), and 9 when the key is in 'run' and in 'start' at the pcm plug? Just pull the plug and measure or stick a pin through the wires' insulation to test for voltage. Also, because you mentioned grounding, test that pin 5 is showing a short to chassis ground.
If those voltage check out, then listen for the fuel pump to run for about a second when you turn the key to 'run'; and check for spark while cranking the starter motor by means of a screwdriver inserted into a spark cap and while holding the insulated handle place the shaft of the driver 1/4" from the cylinder head while a helper cranks over the engine.
