How many miles? Didn't 2003's come with 7/70,000?

 

P0888 trouble code.

Check the wiring harness going to the transmission and to the relay, as well as the ground straps to the engine and transmission.

Also (and this is a bit of a shot in the dark) make sure your battery cable connection is secure and not corroded.

- G

 

The car has 72700 miles. Lucky me...

From what I remember, the shop checked all of the wiring and ground straps. It is a new battery??? Probably 6 months old, and this is when all this started getting worse... Hmmm... Could the battery be causing this?

Could it be a speed sensor? The shop indicated that it's probably GIGO coming from the TCM.

 

The car has 72700 miles. Lucky me...

From what I remember, the shop checked all of the wiring and ground straps. It is a new battery??? Probably 6 months old, and this is when all this started getting worse... Hmmm... Could the battery be causing this?

Could it be a speed sensor? The shop indicated that it's probably GIGO coming from the TCM.

In my daughter's 1999 GC SE the transmission stayed in 2nd gear when it had about 85,000 miles on the odometer. The problem with her GC SE transmission was an "O" ring somewhere in the transmission and the repair cost was quite reasonable at the Dodge-Chrysler-Jeep dealership.

 

Apparently the P0888 DTC is

TCM Power Control Relay Sensor Circuit.

I just replaced the battery and checked all battery connections to no avail. I would think it would've been reset over the 60 minutes I had the battery disconnected. It did it immediately after starting up and trying to go. I'm wondering if it's the TCM?

 

Do you perchance have the tools & documentation to actually probe and monitor the transmission relay sense line where it goes into the TCM? The TCM is apparently not liking what it is seeing on that line, and so shuts down the trans power relay which results in limp-home mode (all electronic shifting functions of the tranny are completely disabled, so you get only one forward gear).

I am guessing you should see 0 volts on the TCM relay sense line when the relay is off, and full battery voltage (12.6V engine off, 13.5V - 15V engine running) when the relay is on.

- G

 

A couple of inexpensive things you could try:

1 - take the van to an autozone or advance or whatnot and have them do (free) testing of the battery and charging system. Just in the off chance...

2 - with the engine off, open the fuse/relay box and remove and reseat the EATX power/shutdown relay (or transmission power relay, or whatever they are calling it).

 

Pulling out the EATX relay for few minutes and reseating it helped. But as soon as I turn the car off and let it sit for awhile it fails and goes in limp home mode - 2nd gear.

 

Problem solved.

The ground to the EATX had low resistance. Had to run a wire directly from the ground of the EATX to the battery.

Thanks again for all of the help and suggestions.

 

I have 05 T&C with same problem. Relay replaced in April and again in June. Going back tomorrow with another check engine light. Has 53k miles.

Had P0888 code when car had 10k miles.

 

P0888 trouble code

The code is gonna keep coming back until you check all your ground wires under the hood.Clean and remount them check for broken and unattached wires and repair them.You are getting that p0888 code because the relay is still in the closed position and not energized to be open once its open your relay is working correctly.Had the same problem on my 05 Pacifica until today car has never shifted this smooth 48785 miles.Love it

 

Have you checked the battery voltage with the car running?

You could have an over voltage condition.

You can make an adapter that fits into the cigar lighter, and read voltage with a $10 voltmeter.