2002 Jeep Laredo

Transmission problem
2002 Jeep Laredo 6 cyl Two Wheel Drive Automatic 88500 miles

About 1,500 miles ago (86,500) I experience transmission not shifting from 2nd to 3rd with my 2002 Jeep Grand Cherokee Laredo. The problem was not consistent as sometimes it shifted sometimes not. The check engine light also came on. The last transmission fluid change was at 50,000 and again (at the 50,000 mile mark the fluid was a little low too- but not low now), but no leaks were detected then or now. I had the fluid changed at 87,000 and the problem stopped including the check engine light went off.
Now after 1,500 miles same problem again of not shifting from 2nd to 3rd gear, but this time it occurs consistently with the check engine light staying on.

What do you think the problem is and what should be done? Thanks for your opinion
August 21, 2010.

Hi Donald4444,

Thank you for the donation.

Get a free scan done at Autozone to retrieve the trouble code for the CEL indicationg and let me know the EXACT trouble code.

Without the trouble code, it is not possible to understand what is malfunctioning.

Aug 21, 2010.
Per your request I drove to AutoZone - 8 mile drive round trip and jeep shifted normally - engine lite still on. AutoZone troubleshooting testing showed P1762 code Definition: AAGoevnor pressure sensor offset voltage too high or AAlow. Explanation AAECM detected the offset voltage was out of spec for AAmore than 3 seconds. Probable cause = AA1 Internal transmission failure AA2 Open or shorted circuit condition.
Also P1757 code AAGovernor pressure above 3 PSI at 0 MPH. AACEM detected vehicle not moving yet governor AApressure is above 0 PSI. Probable cause = AA1 Internal transmission failure AA2 Open or shorted circuit condition.
So- What does the above mean in terms of what type of repairs am I facing? Thanks

Aug 21, 2010.
Most probably the governor pressure sensor and transducer have to be replaced.

I will send the diagnostic files to you.

Aug 21, 2010.