Hey yall, 2000 Jeep XJ, 4.0L, 4WD, AW4 trans. Over a year ago my obd2 port stopped sending me a full data stream. Now I only see the tps data - nothing else. There are no codes. At around the same time, the check engine light started to come in intermittently. I’d hit a small bump, and it would turn on. Id smack the dash and it would turn off. Again, no codes. Engine runs and acts just fine. Soon after this started, I pulled the engine out and rebuilt the whole thing. I just got her back in, started the jeep and then remembered this stupid electrical problem; it’s still there. As part of the rebuild, here are the things I did, and things ive tried recently to fix this:

1. replaced tps, crank and cam position sensors, map sensor
2. Thoroughly cleaned the engine bay grounds (3 on block, 1 near battery on fender) except the one closest to the ecm. Doing that next (if I can find it).
3. Replaced the ecm with a factory rebuilt and programmed one.
4. New spark plugs, new coil pack.
5. swapped out the main wiring harness with one off ebay (I accidentally tore up the old one when i pulled the engine).
6. disassembled the dash, checking the obd2 reader right after i removed/disconnected: radio, climate, cigarette lighter thingy, cluster. Removing these things did not bring back the data stream.
7. Replaced the obd2 port.
8. the obd2 reader is a creader 3001, and works fine on other vehicles.
9. This is an SE model Xj. Does not have abs.

i plan on checking the wiring harness to the cluster for broken wires now that the dash is disassembled. I also am trying to find and check the ground for the instrument cluster and can’t. I have the drawing and see where g108 should be, but I can’t find it. I suspect I have a short and/or a bad ground somewhere in the dash due to the intermittent nature of the CEL but the data stream thing has me stumped.

Do you guys have any suggestions?

 

Never mind; problem solved!!!

 

what was the problem?