I have read several threads about this. I have checked all of the fuses. I'm having trouble finding the correct PDC diagram.
Not sure if the model came with an ABS relay or not.

I have a 1998 Grand Cherokee Laredo 5.2

 

I also have power on pins3,11, and 16. Good ground on pin 4

 

Could this be the PCM isn't working? Since the transmit and receive don't seem to be working at the odb connector.

 

First step would be to obtain a wiring diagram from the fsm and make sure you have power to the pcm. No communication with the pcm is a good indication of a connection problem, either internal to the pcm or externally. Apparently the zj pcm's are made by two difft manufacturers. If your scan tool works with other vehicles yes I suspect a pcm connection problem. You may benefit from this video
http://www.youtube.com/watch?v=-cAt9...ature=youtu.be

 

 

The PCMs in most Jeeps last a long time. They're manufactured to last more than 125,000+ miles, however I've seen videos with broken ones, perhaps going off-road, rough terrain, through water, etc. sustain damage? From what I know about them most should have a separate section that produces 5 volts for the sensors, which I seem to remember also has the EVR (electronic voltage regulator) for the alternator.

Breakage sometimes is only with the connector that goes the 5 volt or EVR section. (There are pcm repair videos that can be found on youtube, etc.)

Most PCM problems are related to it's sensors and wring input and ouput and not normally with the PCM itself. However I keep a spare, picked up from the JY for $50.00 just in case it stops working.

I found one in the JY with nearly the same part number which are usually the same for the same year, engine and emissions type. (Calif, Federal, etc.)

The JY PCM that last two digits were different from the original. Some of the pcm part numbers will change depending on the year, model, engine and emissions type.

The last two digits usually indicate a PCM revision, so an AE would be a later revision than an AD. You don't necessarily need to have the latest revision PCM which can be updated if you have a DRB scanner (or re-programmer) and the code (which usually can be purchased for around ~$20.00 from https://www.techauthority.com/

I think if you have a PCM programmer and the code you can reprogram the correct type of PCM to work with your vehicle. IIRC they used the same PCM for various Jeeps where the only difference was the programming, (code).

 

I purchased a new PCM from Flagship. I still have the same issue. Going to trace back the wiring (hopefully)!

Thanks

 

Thanks, I have tried running, and everything else. Still no workie.

 

I have power and ground. Trying to verify continuity from wiring harness to ODB connector.