We have an 05/1999 jeep cherokee sport with the 4.0l and the aw4 trans. The check engine light, check gauges light came on and the odometer went to 100 mph while only doing 5 mph. The car shut down but later on i was able to restart it and it is now in my shop. I pluged my " innova " to hopefully pull a code, and it read p1694. I found your website and like what i have read so far. I bought this jeep new and plan on driving it until it is complete junk. Iam a retired dealership mechanic and service writer and i take very good care of our cars. I need your expertise to help me solve this shut down! It only has 225,000 miles on it, and ive given this great jeep every thing its needed. Thanks for helping us! Dougie

 

Crankshaft position sensor seems to be a common fault.

A common issue with the automatic XJ's where the vehicle stalls, does "crank-no-start", but once the engine has cooled down will start right back up is the CPS. Thermal failure. If you replace it, get the Mopar. All the aftermarket ones are hit or miss with a lot more miss. Mopar uses a better magnet and is much more likely to give you many more years of service.

Another common issue with that gauge cluster is moisture - I think there was a TSB about it many years ago. You can pull the cluster and clean up the connectors and put it back together with a bit of dielectric grease if it's just the cluster pulling random "no bus"s.

 

I replaced the CPS as you suggested. It was a good time to replace the CPS anyway, at almost 20 years old and 225,000 miles. I installed a new NAPA/Echlin Part #CSS638. Then I shut the door, fastened the seat belt so I could hear the "zing"/stop of the fuel pump. I did not hear it as usual, but I turned the key to the start position and the car started right up. I let it warm up for about 15 minutes to operating temperature. I went to move the car, put it into reverse and it rolled back about three feet, and the check engine light came on and the car died. I shut the key off and plugged in my Innova Scanner and turned the key to the on/no run position and the scanner said it could not establish a link; then I noticed that in the place of the odometer where you read the mileage were the words "No Bus". I have been studying your website and read about the guy with 1997 XJ who was having similar problems. It was the Jeep that swamped and had mud in the connectors and had the upgrade of his diff to a 8.25 and disc brakes. You showed him diagrams of the PCM, DLC, TCM and Dash cluster and how to test them for failure. I noticed that the 1997 XJ has 26 pins at the TCM whereas the 1999 XJ has only 24 pins. I can do the testing, but I need help to diagnose this problem. You had mentioned that the TCM can corrupt the PCM. The test I did at C3 gray connector at the PCM Pins #28 & 30 checked out at 120 ohms. I need to properly run these tests from the PCM to the DLC; the PCM to the TCM and any other advice and diagrams that you can help me with concerning testing the dash module. I did pull the dash module and all the pins are in very good condition with no sign of moisture at all. I will leave the dash module out until all the testing is done. I appreciate your knowledge, wisdom, and help so that the problem can be located and repaired or replaced. Thank you again for your help. Dougie

 

What did you find? I've had many wiring problems with my 99xj and anything i can look for helps. I currently have most of the wiring harness stripped and found 2 cut wires at the dipstick for the trans.

 

this may be one case where the parts cannon might be justly applied

I would be inclined to grab a '99 TCM from the Wrecker, and slip it in, should only cost ~$100

they are known to fail sometimes

 

I might just have to try that. I've done too much to list and now I'm getting p0700, p1687, and p1698 codes. The trans shifts erratically. 1-2 shift happens immediately. Thanks.

 

I am not 100% sure, but think you need the ignition key (and (helpfully) ignition barrel) on a post '96, if you change PCM,
as they have a security system which recognises the VIN, which is programmed into the KEY (I think)

The VIN reader is in the Ignition barrel, and sends to the PCM...without this VIN recognition, the vehicle will start for ~3secs, then stall

"Re-manafactured" PCM have the VIN re-programmed by the supplier...you have to provide VIN to them

On a '96 & earlier, there is no VIN recognition in the PCM, (or key barrel)

I stand to be corrected on any of the above

 

You should send a PM to Noah911. He's the one who gave us all the info about testing the CCD bus, what voltages to find where, and wire color codes. I think he said any single wire with a violet tracer is the bus. He said something about testing the voltage and start unplugging the modules until the voltage drops to within limits and that module is the problem. That's all I can remember, but he's the guy to go to.

Wait! I just realized I was talking to someone who was here in February! Whatever......