QuestionQUESTION: When the jeep works it's a dream--(90,000 mi) but intermittently (sometimes 2+ months) it will quit after stumbling and bucking while driving (highway), and at the same time backfire like a nuclear bomb (blown out two mufflers. Sometimes it will happen as we are leaving the driveway--three--four minutes after starting up. It seems to drive better without a muffler, which we don't want to replace until the problem is solved. Dealer can't figure it out. Ignition fuse replaced, ignition coil replaced, distributor cap and rotor replaced, throttle position sensor replaced. Spark plugs and wires seem fine (but maybe not?) Gets terrific fuel economy. Fuel filter has been changed. Catalytic converter just replaced (recall). Battery is good. No mechanic (dealer or otherwise) seems to be able to find the problem, even though two diagnostics have said ignition is the problem! Also when it quits the steering locks. It's frightening. Needless to say, we have been using our other vehicle now, but want to get back into the jeep!! Oh.. the dealer said the O2 sensor could use replacing but was not the problem.
As I mentioned, when it's running fine (in-between the quitting, it runs beautifully.
Thanks in advance!
ANSWER: the code u are talking about is this one right??
IGNITION COIL #1 PRIMARY CIRCUIT
Need a PCM
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QUESTION: Thanks so much... but another question regarding that. Just so we know..:-) Where is the PCM located and can we change it ourselves? Also, we just replaced the ignition fuse today--40 amp(that I mentioned before), which the manual states is also for the PCM. We took it for a test drive and it did wonderfully--no hint of wanting to fail. But that seemed too easy (and the failing has always been intermittent anyway) However, there is another fuse for the automatic shutdown and PCM, which is 20 amp. Should we also replace that before replacing PCM itself? Besides primary I believe the code also read #2.
Thanks again in advance.
ANSWER: did u just replace the fuse because some one told u to or was it blown? Same way with the ASD relay fuse? Fuses dont go bad unless there is a short to ground on them. SO was that the code IGNITION COIL #1 PRIMARY CIRCUIT that they were getting?
And the pcm can be replaced by u but will haft to be programed by a dealer or a shop with an expensive scanner. The pcm is on the passenger side fender well with 3 connectors coming out of it.
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QUESTION: We replaced the fuse because we felt it might be failing. The prongs seemed to be somewhat corroded... Maybe that isn't the right word, but they were discolored and we were able to clean the one we replaced (out of curiosity). Bought the jeep used so we don't have a clue what is "new" --recently replaced -- and what isn't.
We'll take a look at the PCM. I heard that if you tap on it (handle of a screwdriver etc) while the car is running, and the car falters, that it is bad. Any truth to that? And can the connecters themselves be bad or loose--and be replaced instead of the unit itself? Pretty expensive module!
Answeryour PCM is bad ne way u look at it u have already done everything else as far as the ign system When i get this code at the dealer i replace the coil pack and a PCM and no probs after that. Yeah the pcm is kinda high 400 on up. ANd tehn have it programed as well.
