QuestionQUESTION: First problem: when alarm is armed, it will randomly start sounding on its own. will disarm with the remote, but when armed again, it will go off again eventually. if kept unarmed, will never sound. BCM maybe?
Second problem: I'll start from the beginning... bought the car,had a bad tranny. put a tranny in. speedo or nothing worked,(couldve been faulty prior to tranny) a/c compressor wouldnt come on. (full of freeon, etc). after i put a used PCM in it, a/c started working, and speedo and everything else started working.(doesnt have the chipped key by the way, so i didnt have to take to the dealer for a re-learn) well, eventually a/c compressor wouldnt kick on again. put another computer in, didnt fix it this go round. long story shorter, ended up replacing the transducer, relay,and control head in the car, all used out of another supposed to be operable vehicle (has digital control, by the way). basically i'm wondering what the next step is. is there a TSB you know of about this type of problem? or if you recommend a wire trace and check, do you have a wire diagram of the a/c system i could use to verify grounds and voltage? I know my way around cars i just dont have access to the info anymore. I was a local nissan/gm tech, but our dealership went out of business. any help would be appreciated. thanks
ANSWER: Hi Nick,
Are you sure that your refrigerant is still up to the minimum to close the transducer switch? If so, then checking the wiring is a reasonable next step. I can postal mail you a xerox copy of the wiring diagram which is only 1 page, or I can describe it to you.
Basically, fuse 21 behind the dash powers the compressor relay actuation coil (at pin A) and fuse B in the underhood box provides the current controlled by that relay (via red/brown to pin B of the relay), then to the compreesor clutch. Pin 64 of the pcm is what controls the actuator coil of the relay at pin C by a grounding action. It will do so if the pcm gets the go ahead from the transducer on pin 42 from transducer pin 3 (dark blue wire). The transducer needs a 5V supply on pin 2 coming from pcm 61 on violet/white wire. Sensor ground on pin 1 goes to pcm 43 (black/light blue). Clutch current comes out of relay on pin D and is carried on dark blue/black wire. Clutch ground wire is to rear of block.
Good luck.
On the theft alarm, I suspect one of your doors is not tightly enough latched so try moving the striker in board a bit on the driver and passenger doors. That would give a false alarm if the ajar sensor was just on the edge of 'going off'.
Roland
PS Sorry for the delay but I just found your question in the 'pool' to which it had been referred by the other expert. Please 'rate' my answer, and where you see the question about 'volunteer of the month' please consider giving me a 'yes' answer. Thanks
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QUESTION: No problem with the delay in answering. Its a free service. If it was a week, I wouldn't care. Thanks for getting me out of the pool.LOL
Thanks also for the info on the compressor wiring. Thats sufficient enough that I can find the problem. Just didnt know which pins to check.
As far as the door switches go, would pulling the dome fuse be good enough on this car to disable door sensors? Also,if it turns out to not be a door or trunk triggering, what would be the next thing to check?
AnswerHi Nick,
The problem with pulling the IOD fuse (#19 in the dash) is that all the courtesy lights are extinguished, and further I am not certain whether that fuse, which powers only part of the body control module's needs*, will cancel the self-locking of the doors. I believe you will find that there is a door that is not sufficiently secured as to circumvent a false ajar message. Let's consider what to do next after you have tried that fix.
Roland
*Five separate fuses send current to that module.
PS Thanks for the rating of my answer. Feel free to do it again...there is no limit!
