Hi, I have inherited my dad's 97 5.2l grand cherokee after he passed and my mom had trouble with it. She left it at a shop, they claimed it needed a pcm and they "couldn't get one". I got it back and it wouldn't start and my scanner wouldn't talk to the pcm.

Best I can tell, I dont have a security module, there is no unit in the left side panel in trunk. I dont have a key fob, I assume there never was one.

I installed a programmed pcm off ebay ($220), now it will start and run for 2 seconds then shuts down very consistently. Best I can tell its the vtss (vehicle theft security system) shutting it down.
I have replaced the crankshaft sensor, camshaft sensor, distributor cap and rotor.
I have tested all the fuses and swapped all the relays.
I have tried disconnecting the lift gate lock sensor, the connector for the vtss module
I have grounded the #71 wire for the vtss disarm sense (tried grounding both bcm and pcm side each)

Does anyone know of any things to try?

 

Check the SKIM module if you have it. It’s a gray box around the steering column near the ignition lock cylinder. If present, you need the programmed key. If not, your replacement PCM might be mismatched. Verify the exact PCM part number matches your Jeep’s build (engine, transmission, 4WD, etc.). Try leaving the ignition in the ON position for 10-15 minutes without starting. Sometimes this allows the PCM to resync. Double-check all wiring and grounds, especially the main engine ground near the dipstick. Also, confirm fuel pressure isn't dropping after start.

 

Thanks ill check it this morning, I did try the key on for 20 min a few days ago no luck.
I also checked the ground, I had to remove it to put the Crank sensor in.

 

The crank sensor needs the reluctor ring to be perfectly aligned. If the ring slipped when you removed the gear, the sensor won’t read right. That’s likely your issue. Double-check that ring alignment.

 

I only removed the Crankshaft position sensor in place, everything is still installed

 

I am not 100% sure but I dont see any skim module on my column and it looks like the key doesn't have a chip in it. I am assuming at this point the replacement pcm was flashed for a truck with vtss or skim?