TCCM DTC C0378 HELP "ENCODER MOTOR REPLACE?"

[neto1978]

HI THERE, MY SUBURBAN LTZ 2007 HAS ONLY 20K MILES AND THE "SERVICE 4X4 MESSAGE ON IPC ONLY WHEN IT´S ON AUTO OR 4WD HI MODE.

USED THE GM SCANNER AND CODE C0378 WAS FOUND, NO MORE CODES.

THERE'S A TSB 07-04-21-002, so;

I Have UPDATED THE TCCM TO THE LATEST VERSION USING TIS2WEB.

REPLACED THE 4X4 SWITCHER.

I just didn´t check the C2,C109 and C110 connectors pin terminal tension (because I can´t believe its the case...)

after all the same message haunts me...

I SEARCHED THE HELL OUT OF EVERY POSSIBLE FORUM, NO 100% SURE ANSWER.

iS THIS A CASE OF REPLACING THE TRANSFER CASE ENCODER MOTOR SO PREMATURELY?

TKS.

[00Silverado4x4]

Look up encoder motor sensor on Youtube, there are several videos of people that have taken them apart and fixed them for next to nothing. Worth a shot compared to replacing parts that only MAY fix your issue. Just a suggestion.

[neto1978]

UPDATE.

I JUST REPLACED THE ENCODER MOTOR SENSOR, JUST TOOK CARE OF EVERY DETAIL... PUTTING THE TC ON NEUTRAL BEFORE TAKING THE ENCODER MOTOR OFF...ETC...

RUN A FEW MILES, THE MESSAGE CAME BACK..."SERVICE 4X4 "

 

I HAD REFLASHED THE TCCM BEFORE THE REPLACING TO THE LATEST UPDATE...

Q: SHOULD I DO THE REFLASH AGAIN?

ANSWER:????

I AM LOST ON IT!

[00Silverado4x4]

At this point I would get it scanned for codes again. Otherwise you will be guessing what the problem is. Check all your fuses related to the 4wd. You should have one for the transfer case and one for the front differential.

[neto1978]

C0378 again,

Maybe i should replace the actuator switch?

[neto1978]

Anybody could help me with Document Title: #06-04-21-006A - Info - Description, Operating Characteristics and Diagnostic Information of New NVG Transfer Case (RPO NP8) for New Style Pickup and Utility Models - (Jan 11, 2007)

 

I need to take a look at it...

[neto1978]

After thinking a litle bit more and a replacing not necessary parts like dash 4x4 switch and TRANSFER CASE MOTOR ENCODER SENSOR, reprogramming tccm module...FINALLY I CORRECTED IT!

FRONT AXLE 4x4 ACTUATOR WAS RESPONSIBLE FOR INTERMITTENT "service 4x4 message".

Bought it at amazon, genuine GM , replaced it and run...