donaldj79

OK...Bought an 05 Grand Cherokee HEMI with 195K Miles, Truck was running fine. I was letting someone take it for a Test Drive and the Heater Core Blew. Fixed that. Next the Power Steering Pump was whining. Fixed that. After replacing the Power Steering Pump, the Truck wouldn't shift!! Long hesitation going into Drive and long hesitation going into Reverse. Truck is in Limp Mode. Even when I use the Auto Stick and put it in 1st Gear, Truck does not engage. I have to raise the RPMs to get the truck to move at all.

Here are my questions:
Could the mechanic have done anything at all wrong when changing out the Power Steering Pump?? Knicked a wire? Cut a ground? Anything at all that would show these symptoms?

Would the water/antifreezee ingress from the Heater Core leaking on the passenger side Floor Board have fried the Shifter Module, PCM or BCM? I do see a line of wires running down the right hand side of the passenger floor board. I have dried the Floor Board out as much as I could.

After replacing the Heater Core, the truck drove fine. I did see the radio going in and out and the horn would blare out of nowhere. So I assumed something got wet. But not sure what exactly. Truck still drove fine. I put about 60 or 70 miles on it since the Heater Core was replaced. NEVER a shifting or transmission issue. Only started after the Power Steering Pump was changed. Which leads me to believe he did something...

Here are the codes...P0700, P0731, P1790, P0868, P0733, P0944, P0732, P0876, P0888, P0891

I read some other posts about P0888-transmission control module off. I checked all fuses and swapped relays for the EATX. No Change!!!

Hoping someone can point me in the right direction. I have NO experience with these Jeeps.

tony270

If I had been tasked to figure out this issues, this in general and not specific to this vehicle, check your manual:
Anytime I work on a cooling system I change the thermostat, change or test radiator cap, check to see if bleed the cooling system if required, and I always make sure the coolant (Anti Freeze) is at the correct ratio, if using 100% ethylene glycol dilute it with distilled water, or use pre-diluted 50:50 "follow the OEM specs", normally 50:50 in regular temperatures, the coolant can be tested with a deuo check or a hydrometer. Normally extreme coolant temperatures can effect shifting patterns in some vehicles, the PDC continually monitors the coolant temp and communicates with the TCM.
I make sure that the cooling system if required is primed per the FSM. I also check to see if the PS pump pulley is not binding of frozen (some vehicle use a clutch pulley). Some vehicle even use the power steering fluid to cool off the diff gear oil, like some HUMMWV's. So you need to read the specifics for your vehicle.

Oh and as far as those codes I would do a master reset, the reset that drains all the capacitor setting the logic back to the factory settings (learning mode).

tony270

And I would try to soak up as much coolant that leaked onto the electrical components using a extra absorbent napkin and spread some rice grain around to help (anything hydroscopic), and use a heat gun or blow dryer on medium heat to help dry things out.