Thanks for the link. After reading through it do you think the problem could come from a bad ground? I have checked the harness ground and many of the computer grounds already, but could new advice on it. Also I did find something today when I went out to look at a few things. My new battery was dead and would barely turn over, so I could not check the data port. Have not had any issues and it is new and only a few weeks old. Can a bad ground cause a draw on the battery somewhere? Any way to test for that?


I have already depinned B31 from the computer which is the 5 volt output to the VSS so I am not sure that can be it. What do you think?

No, but I would charge the battery and have it tested at the parts store. When troubleshooting an electrical issue, the last thing you need to be doing is wondering if the battery is good.

Remove the Ignition Off Draw (IOD) fuse from the PDC (location shown on the cover of the PDC), charge the battery (with the IOD removed). After the battery has been charged (and the IOD still removed) see if the battery drains.

There are several circuits on the IOD. One or more may be draining the battery. If the battery retains its charge over night, one of the IOD circuits is faulty.

There are two circuits on the IOD that may be causing your original problem; the Transmission Control Module (you said you had a P7xx fault), and the Instrument Cluster. I would think about the TCM first. Since you have a P1694 these are prime suspects.

Replace all removed PCM connectors.

With a fully charged battery, do the voltage checks on the CCD Bus (+) and (-) circuits. If any one of these circuits is out of spec (above 2.8 or below 1.8 volts are max out of spec), unplug the TCM, and see if the CCD Bus returns to normal and see if the 5 volt supply returns to any one of the engine sensors. If so, the TCM or its wiring may be faulty.

Do these checks and see what you get.

Another item worth a look could be your battery temp sensor. It's a little springy thing that sits under your battery in the tray. If this is bad, the PCM could cause your alternator to overcharge and kill your battery. It doesn't sound like this could entirely be your problem, but might be worth the time to check it out, and definitely scope out that no-bus issue.

Thanks again everyone for the help. Okay I got the battery all charged back up and checked CCD Bus + and - circuits and had 2.45-2.49 volts between 3 and 4, 3 and 5, and 11 and 4, and 11 and 5. So these are all within spec correct? I removed the IOD and am waiting to see if it is dead again. I also unhooked the TCM and it made no change in voltage on A17 or B31. Both still had only .4 volts. I even tried it with the TCM out and B31 unhooked and still not change. Strangely with the TCM unhooked if I scan the codes I do not get the code P1694, but if it is hooked up I do. Could this simply be the problem that the TCM is not getting its correct 5 volts and throwing a code for the TCM?


Finally I have done the test on the gauge cluster and all worked and swept through the test like they should, so can there still be a problem with the Cluster? I feel the root of the problem is the ECU since it regulates the 5 volt signal and all the grounds and 12 volt signals in and out check out ok. Is it possible if the Crank sensor went bad that it cause a short in the ECU?

So a little update. I decided to buy a used computer from a local yard to see if my issue was fixed. They only had a 534AD and mine was a 534AF, but it came out of a 98 Cherokee with an auto, like mine. I popped it in and now I have 5 volts back on A17 and B31 and my volt gauge and fuel gauge are working like they should. I did not have time to check for spark, but the fuel pump did not run. I jumpered the relay and the fuel pump ran but it would not start so there is probably no spark still. I did forget to plug the TCU back in, but am not sure that would cause a no spark or fuel condition. Can a bad cam sensor cause a no fuel no spark issue?

That PCM may be defective (junk yard Jeep) or it came from an XJ with Sentry Key Immobilizer System (?).

Maybe you should get a known good PCM and install it.

I had some time to look at it today and the fuel pump is running. I can not find my fuel pressure gauge so I can not verify how much but I do hear it prime now for 2-3 seconds when you turn the key on. Also the injectors are firing which I verified using a noid light. I still do not have spark but I was able to verify today that the camshaft position sensor is working. It goes from 0-5 volts with the engine cranking.


I also checked the coil and with the Ohms set to 20k both pins had 10.40 ohms. Is this a normal reading? Lastly I verified that the crank sensor was getting 5 volts, the ground is good, but what signal should the gray/black wire have? Is it a 0-5 volt signal as well?

Well final update for my Jeep. After retracing the wires and triple checking everything a friend let me borrow his coil and finally it started right up. I have no idea how my Jeep ended up with all the issues it had, but it is all fixed now. I have seen rare cases where the crank sensor dies and took out the computer, but no idea how the coil ended up bad as well. Bought a new coil from the dealer today and all is well. Going to drive it a bit and see what the transmission code is.