Jeep Cherokee XJ dies: Investigating why Jeep loses power. 

Common problem on a number of Chrysler models. I personally haven’t had that issue on my ‘95 XJ but experienced this on my ‘93 Dakota 3.9L. I’ve replaced it twice in the past 5 years. Needless to say…..I always keep a spare in the glove box 🤷🏻‍♂️

You had a fleet..My 1993 went..

found this on a jeep forum: Recently my 01 Jeep Cherokee has begun to stall while driving. A short time after driving (couple blocks) it will just cut out. No rough engine stuff, no check engine light, just cuts out. Elec accessories work after/during the cut-out. After an hour or so, it will start right up again. Again though, after a very short drive, it will cut off again! This jeep has never been driven rough--owned the first 16 years by a little old lady--mother-in-law. I've had it less than a year. It just turned over 100K miles. ---- Jeep owner responded---- The Crankshaft Position Sensor (CPS) CPS/CKP can stop working with no warning or symptoms and the engine will not run or the engine may randomly stall for no apparent reason. CPS/CKP failure is very common. Crank Position Sensors can have intermittent "thermal failure". This means that the CPS/CKP fails when engine gets hot, but works again (and will test as "good") when it cools back down. If you perform the following tests and they do not conclusively point to a faulty sensor, consider that the symptoms may possibly be from a fuel pressure issue. Begin with basic trouble shooting of the start and charge systems. Remove, clean, and firmly reconnect all the wires and cables to the battery, starter, and alternator. Look for corroded or damaged cables and replace as needed. Do the same for the grounding wires from the starter to engine block, and from the battery and engine to the Jeep's frame/body. Jeeps do not tolerate low voltage or poor grounds and the ECM/ECU may behave oddly until you remedy this. Symptoms - - Starter cranks and cranks but engine won't start up and run. - Fuel gauge and voltage gauge may not work or display properly. - You sometimes will have No Bus on the odometer after 30-60 seconds. - A failed CPS/CKP may or may not throw a CEL trouble code. - No spark at the spark plugs. - Fuel pump should run and prime for 3-5 seconds. If the CPS/CKP is failed sometimes the OBD-II trouble code reader cannot make a connection to the ECU/computer or cannot read Check Engine Light/MIL codes because the CPS/CKP has failed. Disconnect the code reader, disconnect the CPS/CKP wire connector, and reconnect the code reader. If the code reader establishes contact with the ECU and scans, your CPS/CKP is failed and needs to be replaced. Diagnostic steps to confirm the CPS is the cause of your no-start You should be able to verify a bad cps, by unplugging it, and turning the ignition key to on. If the voltage gauge and/or the fuel gauge now displays correctly, replace the CPS. Unplugging and reconnecting the CPS sensor where it connect to the main harness near the back of the intake manifold usually resets the ECU and if the jeep fires right up after doing this you can bet that the CPS is faulty and needs to be replaced. Exchange the fuel pump relay and the ASD relay with one of the other similar ones in the PDC to eliminate the relays as the cause of the no-start. Confirm that the fuel pump to runs for 3-5 seconds when you turn the ignition key to ON. Inspect the wires and wire connectors at the O2 sensors on the exhausts pipe. A short circuit from melted insulation or from broken O2 sensor wires can blow a fuse and the ECU/ECM will loose communication. Don't get tunnel vision and assume the sensor is bad (unless it tests bad with a meter). Damaged wiring or a dirty connector can inhibit the signal from making it to the computer. Check/clean/repair wiring or connectors as necessary. CPS Testing Crankshaft Position Sensor Connector (CPS/CKP) . TESTING PROCEDURE 1991 - 2001 4.0L H.O. engines 1. Near the rear of intake manifold, disconnect sensor pigtail harness connector from main wiring harness. 2. Place an ohmmeter across terminals B and C or 2 and 3 (See Image). Ohmmeter should be set to 1K-to-1OK scale for this test. 3. The meter reading should be open (infinite resistance). Replace sensor if a low resistance is indicated. TESTING PROCECURE for 1987 - 1990 4.0 L engines Test # 1 - Get a volt/ohm meter and set it to read 0 - 500 ohms. Unplug the CPS and measure across the CPS connector's A & B leads. Your meter should show a CPS resistance of between 125 - 275 Ohms. . If the CPS is out of that range by much, replace it. Test # 2 - You'll need a helper for this one. Set the volt/ohm meter to read 0 - 5 AC volts or the closest AC Volts scale your meter has to this range. Measure across the CPS leads for voltage generated as your helper cranks the engine. (The engine can't fire up without the CPS connected but watch for moving parts just the same!) The meter should show .5 - .8 VAC when cranking. (That's between 1/2 and 1 volt AC.) If it's below .5vac, replace it. The 2000 and 2001 will have the CPS in the same location on the bell housing, but the wire connector may be on the passenger side, not as shown in the diagram below. Simply follow the wire from the sensor to the connector. .

I had a situation that whenever I made a hard right turn or veered right at highway speeds, the engine and power would just die out. I found the cause by accident while vacuuming one day. The power wiring that goes to the accessory plug on the back of the armrest had slipped out between the armrest console and the drivers seat. There was about a 4mm section of insulation that was exposing the wire and every time I made a right turn the inertia was just enough to make it short out on the seat rails and kill everything. Patched it up and never happened again , but drove me crazy for awhile trying to figure it out.

Yeah. That sensor has been giving us issues. I cut the wire and need to trace it as it doesn’t have voltage. For now her oil pressure reads 0 😊

@@JeepSolid I had three oil sender units go out in less than 2 years. I wrapped it three times in flame proof welders cloth. The sender has not been an issue since. It is close to the block and gets very hot. Try wrapping it. Worked for me.

@@JeepSolidso it was the crank position sensor ? Having the same problem right now

Thank you. This one was weird. All electrical would die on her. Everything

I agree if all electrical goes out all at once I’d check ignition , PCM, PDC, fuses, ?

Good idea. Thanks

Going through this with my 02 WJ overland

???

Spare mounts in the trunk space. Where in relation to the rest axle? I guess I could follow the fuel pump wiring.. Thanks for the feedback

@@JeepSolid Yes, in the trunk space.The panel behind the spare tire. Remove spare and bracket mount and LR side panel..There are 2 grounds on a 98 cherokee. and only1 on a 2001 cherokee.

There is rust prevents spray

I'll have to look

Yeah. So far so good 👍🏼

Yeah, I hope this is the simple fix. So far, so good 👍

​@@JeepSolid was it her pcm that was bad ?

That can cause the engine to stop, but we we’re losing all electrical. Everything 😬

@@JeepSolid Yeah you are right sorry I forgot you are losing electrical things, Im sure its just a corroded ground that you cleaned but as a xj owner keep us updated!!

​@@JeepSolidclean the ground cables.

Tap all fuel injectors

Also idk if the Cherokee has the key feature to show the check engine codes by my scan tool didn’t show any codes but when I did the cycle key 3 times trick it showed me the codes