Chrysler Repair: 04 Pacifica in limp mode: code 0750

Question
QUESTION: Starting from the beginning.2004 Pacifica.
Driving along charging light comes on, shortly followed by shutting down to limp mode.
Tracked it down to broken grounds at the trans mount and engine mount under the air filter. Fixed the grounds and removed & cleaned up the others.
Also found fuse to eatx relay blown (relay is good).
There were several codes. Replaced the input & output speed sensors plus the trans control module.
However still in limp mode and showing 0700 Transmission control (mil request), and 0750shift solenoid A.
Started checking wiring for damage, nothing yet.
Am I on the right track?
Also which connections on the ecm are what?
Thanks.

ANSWER: Hi Dave,
The 0750 code is about the Low Reverse solenoid circuit. The causes listed as possible are:
Malfunction of the solenoid/pressure switch assembly
Circuit from the LR solenoid to the PCM shorted or open
PCM ground open
PCM malfunction
I have the '05 manual for the Pacifica. Is there a separate TCM and PCM? The '05 manual shows it to be a single combined module.
The LR solenoid wire runs from pin 7 of the 8-pin plug on the trans to pin 10 of the #4 plug on the PCM (black/green) and the wire is white/dark green.
So check that wire for being either open or shorted to ground.
The ECM (PCM) connections are numerous so I can't tell you which are what.
Roland

---------- FOLLOW-UP ----------

QUESTION: Thanks.
On the back of the ecm plug there is a red tab.Should the plug pull out once that tab is slid back? It does not seem to want to come out & I dont want to force it if there is something else holding it in that I have missed.

Answer
Hi Dave,
It sounds like you have a ecm and a tcm in that '04 model. But I only have the '05 manual which has the combined ecm/pcm. I suspect that the tab is for locking in the plug and once it is slid back the plug should come out. Because I don't have the wiring diagrams all I can suggest is that the LR solenoid wire should be as I described it to be at the transmission plug but I can't tell you which plug/pin to inspect to find it unless your ecm has 4 plugs.
Roland