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Robert, UK Qualified Car Technician
Category: Jeep
Satisfied Customers: 4708
Experience:  Fully qualified / self employed garage technician in the UK
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I have a grand cherokee 2002 model (diesel automatic). Constantly

Customer Question

I have a grand cherokee 2002 model (diesel automatic). Constantly going into limp mode.
Code p0702 coning up.
Sometimes it will start ok then not change gears and can be corrected by turning off and then back on again, other times it won't change gear when you start your journey and can't be fixed be turning off and on.
Submitted: 5 years ago.
Category: Jeep
Expert:  Robert replied 5 years ago.



Hopefully i can help..


P0702 refers to an "electrical fault" in regards XXXXX XXXXX vehicles TCM "transmission control module" the cars ecu picks up on this hence the limp mode and thus truning off and on each time clears the fault until of course the ecu dedects the fault with the tcm again - the first obvious checks really will be the wiring loom / Connector to the TCM itself just to be sure there is no obvious signs of water damage or pin damage corrosion and such like - also trace the loom too for any obvious issues and deal with as you find.failing that then next possibility is the actual TCM itself internally in regards XXXXX XXXXX circuit board and the only forward is replacement or hopefully repair which will need sent off if you dont have anyone local to do may find some of these companies to send the unit to online so they can test / repair ie: / ..I do hope this helps

Customer: replied 5 years ago.

Hi thanks for that, is the wiring loom / connector easy to get to / check?

Expert:  Robert replied 5 years ago.



It should be - unfortunatly i can't seem to find my images for the grand cherokee so i can point in the direction as to where the tcm is - hence i would of giving them to you above..but check the drivers side firewall corner should be black/silver type finned ecu unit if i recall- then just check the pins are in deed clean and the wiring to the multiplug to the tcm is damaged or shows any signs of moisture or corrosion,also trace the wiring back for the same can get special contact cleaners to clean up the pins and then let it dry of and put it back together.maybe worth before doing that disconnecting the battery first..