phstith

My 98 Cherokee 2WD has developed a refusal to downshift at a light when it is warm. I can manually shift and all is well.
Mechanic tells me codes indicate ECM/PCM problem. He also tells me there is no separate TCM on this model. Is he right? If he is wrong, where do I find said TCM?

Sent the ECM for repair (6 months ago purchased a new one) under warranty. Received and installed "repaired" ECM and have the same problem.

Any help would be very much appreciated.

BuckB91XJ

Not sure about 98s but the TCM in older XJs is under the dash on the passenger side.

waltermitty

TCM is mounted under the instrument panel. Assuming you have a left hand drive vehicle, it is at the drivers side of the lower finish panel. it appears to be fastened with two nuts and is rectangular in shape.

This is according to my factory approved service manual for a 1998 XJ 4.0L AW4 transmission. After checking you profile I could not determine which transmission you have.

HTH

excess650

Your mechanic is incorrect. The AW4 has a seperate TCU. Your issue sounds suspiciously like how mine started and I eventually had to replace the S1 solenoid.

phstith

Thanks very much. I have the 98 Cherokee Limited Sport, 4.0 L, 2WD.

phstith

S1 solenoid, huh? Is that an expensive adventure?

excess650

Aamco quoted me $502 to replace the solenoids(3), change the fluid, and clean or replace the filter.

A local guy quoted me 1 to 1-1/2 hours labor @ $70/hour plus parts. Fluid runs about $20 and the S1 from Jeep, Napa, or Autozone runs about $230. You can buy cheaper solenoids, but I was warned to not do so. I bought OEM Aisin Warner from Jeep and did the work myself in my driveway.

phstith

How do I determine which transmission I have?

Thanks