Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
hopfully I can get some suggestions. 2000 Cherokee cranks but wont start. replaced cps even though I new it wasn't the problem. guess I have an extra now. I have been through almost everything. I get power to asd relay fuel pump, but they do not click on. no 5v ref. no 5v from pcm. I can how ever unplug top o2 jump asd relay and get a 5v ref. still wont start. code that came up is p1694 and the no bus on dash I think its the pcm but don't want to throw parts at it like the cps. thanks for any help
hi how ya doin good job so far the fact that you do not have the 5 volt ref line is a interesting point I would verify power and powers and grounds to ecm and recheck that if we cant establish the 5 volt ref lines we are in trouble possibly
hi im checking things now. I do have power going in the c1 pcm no 5volts coming out. I have checked ccd between dsl and tcm all good. on pcm c3 I have power coming in and out going to asd relay I can jump the relay with jumper wires hooke to relay and get 5volt but still will not start not sure why the relay wont swithch without me jumping it
I did replace the crank sensor all my tests showed my old one to be good but I replaced it anyway figured that wouldn't be a bad part to have a spare of
thanks for the help. I am going to double check everything now. I will let you know the results. correct me if im wrong but the 5v that I disconnected were tps,, crank, oil,map and cam not sure if there is another one I missed thanks
I did check fuses. couple days ago had 1 bad fuse 9 15amp in the jb just sayed starting system also tried resetting pcm zipped tied batt terminals together for a couple hours
Is the 5V ref .7V because a sensor or wire problem or is it low coming out of the PCM?
One easy test is to cut the wire coming out of the PCM and test there (leave enough wires hanging out of PCM to reattach later). If you don't have 5V coming out of the PCM, then it's a PCM problem. Check power and grounds at the PCM.
Cut those two wires out one at a time and check if 5V comes back.
I back probed the pcm . Witch leads me to a bad pcm it’s a Motorola has a Chrysler vin looks to be aftermarket not sure. Pulled it apart circuit board like brand new checked all soder
