Help! Possible Transmission Control Module issue

Here is what I've got folks...
1999 XJ 4X4
4.0 liter (The odometer says 240K+ no idea if it's correct or not)
AW4 Transmission

I bought this XJ a few months ago and have been working on it to get it roadworthy......I finally do and then the real issues started.

I've been fighting a p1694 code issue.
I'll be driving and the engine will shut off. Speedometer dies, Volt meter dies, and fuel gauge dies. Sometimes it will start back up and other times it will not. (this thing has left me on the side of the road more than my ex-wife!)

I DO NOT receive a "no buss code" on the instrument cluster.
I've replaced the CPS, fuel pump, and NSS.
I've done a continuity test on the CCD + and - wires from the TCM to the computer. The wires tested good.
I've cleaned all the grounds and replaced a couple. I've cleaned all the connectors and greased them up with di-electric grease. I'm at my wits ends trying to get this thing going.
Before I drop about $200.00 on a new TCM, I'm hoping you all can think of something that I have missed.

Thanks you!

The orange wire on numerous sensors is the 5 volt supply voltage. If any of the sensors short on the 5 volt supply voltage circuit it can kill your gauges and can cause all sorts of problems.

Volt test the 5 volt supply voltage to your CPS (crank position sensor) or the cam position sensor.

Unplug orange wire sensors until your gauges come back online, then you know the likely sensor causing your issue. It is most likely a sensor, but it may be the wiring or a connector.

Here is the sensor tree for the 5 volt supply voltage circuit.

Thank you.
I'll try that and give an update here in a couple of days.

Ran a volt test tonight. ...
Oil pressure and cam position sensors both had 5 volts going to them.....
The CPS, MAP, TPS, and PCM all had less than 1 volt....
I assume this means that I have a bad wire somewhere between the oil and cam senor and the others....
Is this a correct assumption?

Thank you.

Update.......
Went out to the Jeep Thursday and it started right up.

I traced all the 5 volt power supply wires and they all looked good.
Traced the grounds for the sensors and found the upstream O2 sensor ground had a bare spot. Repaired it and then bundled all the wires back. So far the jeep has been running good. We'll see if it pops up again.

Travelworn said:

Ran a volt test tonight. ...
Oil pressure and cam position sensors both had 5 volts going to them.....
The CPS, MAP, TPS, and PCM all had less than 1 volt....
I assume this means that I have a bad wire somewhere between the oil and cam senor and the others....
Is this a correct assumption?

Thank you.

Click to expand...

What that usually means is you have a sensor short, a sensor doesn't have enough resistance and you are sucking all the available sensor voltage from the PCM back to ground. Which usually shuts down your bus.

I usually unplug sensors one at a time and watch to see when my gauges come back on line or hook up a volt meter with an alligator clip to the ornge wire circuit and watch the volt meter as I unplug the sensors on the orange wire circuit one at a time. If that doesn't work it is remotely possible you have more than one sensor short, unplug them all and plug them back in one at a time and see which sensor is causing the voltage drop.

Could be a connector, sometimes simply unplugging a connector and plugging it back up again cures that issue. Unlikely but possible.

5 volts rarely grounds through water, so a wet connector is unlikely to be your issue. The exceptions are a coolant covered connector or battery acid both are much better conductors than plain water.

Just basic info, not a rule just a tendency, it takes 9 volts or above for there to be *significant* short/electron flow through plain water. The dirtier the water the better it conducts, or in other words mud conducts better than plain water does.

Thanks.

When I had and extra set of hands to check if the gauges came back on when I unplugged them, the issue was "cured". Next time I'll take the time to check as I unplug each one.
Thanks for the info. It was a big help and helped me narrow down my problem.