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!
Hi Dan I’m a disabled grandfather who hasn’t seen his grandkids since Feb. Low income so I have to do repairs myself no matter how hard. I need help please! I have a 96 grand Cherokee 5.2 limited 4x4 and your the expert I have seen on anything Jeep. I had computer issues that only allowed me to crank when my gauges would come on. Also my harmonic balancer had started to wobble. So I replaced CPS first it didn’t fix it but then when gauges would come on it wouldn’t crank at all. Sent PCM off and it couldn’t be repaired so I bought a rebuilt PCM. I installed it and the gauge issue and fuel pump constantly running was fixed but still no spark( cranks no start) I checked CPS 5v and it was good checked ground also good checked signal and had a 5.2v but I bumped the engine many many times and could never get the 0v. I checked the CPS according to service manual. Disconnected it and metered it across negative and signal (meter negative to negative and positive to signal) had OL which should be good? Reversed meter on same wires (pos to neg neg to sig) and got some readings (can’t remember exactly). I have checked ASD relay and connections it plugs into all good. No voltage to coil with ignition turned on. No fuel Oder but I expected that with no spark first. I did ignition test for codes and only get 12 and 55 . Don’t have Obd2. Am I missing something not holding my tongue right or just an idiot? I would really appreciate some advice on what to do. Income low so shop is out. Also after market CPS since dealer and mopar doesn’t carry anything for my 96 anymore. Your the most informative expert I have ever seen on any video or forum
Paul I tested both the green and orange and black and white wire unplugged and on side leading to ASD from coil. No power on either during ignition on and cranking. Positive to each and neg on battery negative. Though I did get .003 MA on cranking while testing black and white
Paul, ok MAJOR CORRECTION I didn’t probe my green and orange properly. Pierced it with push pin I used for probe and got a reading. Initial 2 seconds ignition on I got 11.15 ( battery little low) then cranking I got 1.35 or so to 1.75 didn’t check black and white again
So you have power to your ignition coil during the initial key on but no power during cranking? You absolutely have an input problem and must focus on the crank and cam sensors. You should have trouble codes too related to them
The only codes that have presented themselves on the key self check is 12 and 42. Would the ASD code include crank and cam sensor? As I said before I had taken the relay out I believe while switch was on by accident and replaced it. When I tested the crank before talking to you I got good 5.2 volt reference and a 5.2 signal voltage but I could never get it to go to 0volts by bumping the engine. My ground test on it produced a .400 MA with ignition on and 3 to 4 volts when cranking. I know you have said no more than 100ma on ground but never saw what over the 100 ma meant. Also what is the proper test of the cam sensor?
This question is for ScannerDanner as he has guided me to this point. But any response is welcome. After following your advice to check inputs I decided to remove my CKP sensor that I had installed prior to new PCM. It was replaced first to see if it was my issue. I’ve read where only mopar OEM CKP will work with my Jeep. But in case that 1st aftermarket was DOA I returned it for the same replacement. I’ll install today but I was wondering what the difference was and found a difference I’ll show in attached pics. Could you tell me if this is the cause for the aftermarket not to work? Pic where bit ckp are side by side the top one is OEM. In the pics of the tips of the ckp the OEM has visible metal or magnetic strips with 2 holes under. The OEM does not. Could this be the issue? Can the aftermarket tip be sanded to reveal the same as the OEM?
I merged your topics to preserve continuity and to help from having the same questions answered in multiple posts.
To answer your question, it looks as if the original crank sensor was in contact with the tone ring. I don't recall seeing exposed metal on those.
Did you by chance remove it and reinstall it at some point?
I can tell you from experience the aftermarket crank sensors just don't work well on that system.
I've had them not work right out of the box, or only work for a couple of days.
Never removed. I was curious and looked on Napa’s site and they had same aftermarket but also had a higher priced one that has the strips and holes so I’m assuming that it’s supposed to be that way. Thoughts?
I tried to zoom in on it to get a better look, hard to say...
They usually come with a little piece of paper or something stuck to the end that is supposed to provide sufficient air gap. Maybe that's why I don't remember seeing any exposed metal on the end of the sensor.
thanks for everything Paul! You were right on the money. I had a DOA CKP sensor swapped it out. So new PCM and CKP sensor. . Fixing to test drive it now. Missed my granddaughters surgery this morning but it’s running so I’ll be able to go see her and my other grandkids . Tell your students that sometimes they get a chance to make a difference. You did that for me with just a few answers
