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Robert R
Robert R, ASE Certified Master
Category: Jeep
Satisfied Customers: 3932
Experience:  ASE Master Certified, Chrysler Certified
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2001 Jeep G.C., 190K, 4.7L. downshifts to first going

Customer Question

2001 Jeep G.C., 190K, 4.7L. downshifts to first going uphill, first did it while pulling a trailer. cycled accelerator and turned off O/D to continue. refilled low fluid level but no change. no codes, only says done. sensor?
JA: Which particular sensor are you asking about? And have any trouble codes been triggered?
Customer: not sure?
JA: What is the model of your '01 Jeep?
Customer: read post
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: yes and read post
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 12 days ago.
Category: Jeep
Expert:  Robert R replied 11 days ago.

Hello, welcome and thanks for asking your question. My name is*****'m a Certified Auto Technician with 29+ years experience. I will do my best to assist you. please keep in mind that I may need to ask questions of you before I can answer. When you reply please feel free to add as much detailed information as possible pertaining to your concern.

Does this concern happen all the time now or just when towing? How steep is the hill? IF you top the hill, will it finally upshift on it's own?

Keep me posted...

Thank you,

Robert

Customer: replied 11 days ago.
2001 jeep G.C. Limited. Starting to do it more often. IE moderate acceleration, hard acceleration, and sometimes when in cruise and it wants to accelerate. when in cruise, I have to manually exit cruise or it shifts down to 1st and hits the rev limiter. upon returning to idle, will eventually shift. Have to "baby" it by feathering the throttle. It doesn't shift directly to 1st, but starts to downshift to next lower gear and seems to not have enough power to accelerate so then downshifts again and so on.
Customer: replied 11 days ago.
I have 40 years experience as a general mechanic and have rebuilt several auto xmsns.
Expert:  Robert R replied 11 days ago.

When it shifts to first, what must be done to get it to begin upshifting again? Do you need to pull over and turn off the ignition? Have you tried using a scanner that can talk to the TCM to see if there are codes stored there? Normally the PCM should store a P0700 but it is possible for there to be a code in the TCM and not the PCM.. Another thing that might help is to use a high end scanner that can monitor the transmission while driving so you can see what is going on electronically. If you can monitor it, you may be able to find the problem...

Keep me posted...

Thank you,

Robert

Customer: replied 11 days ago.
I bring accelerator to idle and it up-shifts again and can drive. If I give it too much gas it will do it again. By letting up on gas pedal when it down shifts 2 gears from O/D, I can catch it from going all the way to 1st.
Did the key cycle and got no codes, only "done". I'll try my Mopar code scanner and see if it shows anything else.
Expert:  Robert R replied 11 days ago.

Check the Throttle Position Sensor for problems. It could have failed "in-range" meaning that the voltage is still in acceptable range but it could be sending an incorrect position signal causing the TCM to "THINK" that you have the "Pedal to the Metal"...

Keep me posted...

Thank you,

Robert