Hi all,

Hope all is well! Haven't been on in a few weeks as I've been traveling, but just did a trip in the 2002 2.5CRD on some rough roads here in Costa Rica, and had some weird electrical issues:

For reference, I had disconnected the battery while I was gone and re-connected it once I arrived. Negative side was a little loose for a bit but is nice and tight now and problem persists.

1) Driving on rough roads, speedo went out (stays at 0) and BOTH the brake (parking brake) lights and the ABS light came on in the cluster. I stopped and tightened the negative battery lead and this went away for a bit until
2) Back on rough roads, throttle seems to give out and get a CEL - use the on/off ignition trick and new code is P2120 - for throttle sensor - but now the ABS/Brake/Speedo problem is back. Turn jeep off and restart and throttle is good, but CEL still there.

Car drives normally - brakes are fine, no issues - throttle response is good. Not sure where to start - seems like it must be a short somewhere in the wiring, but all these seem to be unrelated issues, I'd think.... any ideas?

Thanks all!

Hi all,

Hope all is well! Haven't been on in a few weeks as I've been traveling, but just did a trip in the 2002 2.5CRD on some rough roads here in Costa Rica, and had some weird electrical issues:

For reference, I had disconnected the battery while I was gone and re-connected it once I arrived. Negative side was a little loose for a bit but is nice and tight now and problem persists.

1) Driving on rough roads, speedo went out (stays at 0) and BOTH the brake (parking brake) lights and the ABS light came on in the cluster. I stopped and tightened the negative battery lead and this went away for a bit until
2) Back on rough roads, throttle seems to give out and get a CEL - use the on/off ignition trick and new code is P2120 - for throttle sensor - but now the ABS/Brake/Speedo problem is back. Turn jeep off and restart and throttle is good, but CEL still there.

Car drives normally - brakes are fine, no issues - throttle response is good. Not sure where to start - seems like it must be a short somewhere in the wiring, but all these seem to be unrelated issues, I'd think.... any ideas?

Thanks all!

Check the sensor on the rear diff......the cables tend to fray on the nearby brake lines and chaff down to ground.
Also the ABS uses some sensors on the wheels...on your model I think it is one front wheel and one rear wheel but I may be wrong. If any of these sensors are loose or dirty then your ABS light will come on.

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2002 Export CRD 2.5 Sport

I agree with what BillWill said.

One of your wires is frayed.

If you own a 2005 model, then the problem is in the wire harness leading to the ABS Sensor located on top of the rear differential.

The wires are very thin and fray close to the connector.

The break is not visible, the broken wire is internal of the harness and inside the connector, it cant be repaired, I tried.

The connector is sold at the dealer with the wires ($10.00), replace it and the wires.

In order for it to work correctly you must have the wires connected properly.

You must put the wires on the same way as the old ones came off. The wires should be color coded, if they aren't then you need to install them by trial and error before you finalize the connection. The lights will not go off if you don't have the wires on right.

This is what I did to test and see if the wires were on properly.

1. Twist tie the wires together but don't seal them yet.

2. Start and drive the vehicle forward for 20 feet so that the ABS sensor has time to register the fix. The wheels have to spin 2 or 3 revolutions before it registers and the lights go off.

3. If the dash lights did not go off then switch the wires and try again.

Seal and lock the wires in place.

Racer

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2006 Liberty Limited CRD, Deep Beryl Green, Yeti tune, Arp studs, new cams, rockers, lifters, TB. "Green Monster"
2005 Liberty Sport CRD, Deep Beryl Green, GDE Hot Tune, ARP studs. "Rocket"
1982 Fiat 124 Spider Convertible. "Fiona"

At least part of your problem sounds like wheel sensor problems. Don't know about the 2002 but if it's similar to the 2005 you have 1 on each of the front wheels and one on top of the differential in the rear. Given the rough road correlation I'd guess you have a loose sensor or bad wiring (on the 2005 the wiring at or near the rear sensor tends to go bad). Of course you could have a loose sensor.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

Edited: post no longer valid

Thanks, guys! I checked the sensor on the rear diff - looks clean enough and seemed to be on correctly. I'll try replacing it once I can get to the dealer for a replacement.

Any thoughts on the CEL with code P2120 at the same time? Throttle position sensor seems unrelated, but both problems seemed to pop up together...