12VDCGemlinHunter

TCCM keeps popping 4x4 Fuse

2015 SCREW 5.0 4x4 -No locking Diff
Driving down highway 80mph in 2WD and " Check 4x4 " comes up on dash.
I pull over try to switch 4x4 on the dash and no action. I so forward 20 feet I go backwards 20' everything seems normal.
No drivability issue, no unusual sounds so I go to my meeting then drive 70 miles home .

Hook it up to forscan
The TCCM cannot be reached during DTC test.
Every module that communicates with the TCCM cannot reach it.
I discover fuse F72 4x4 (25amp Mcase) is popped. This directly powers the TCCM with no splices.
I swap out the Mcase and it immediately pops again.
I pull the connectors at the TCCM ( C2371B & C2371A ) and replace with another M-Case .
I don't connect the TCCM and voltage at the pins 6& 7 checks good.
Good ground at 1&3
Check for short to ground on pins 4,5,9,10
I pull the connection at C140 to isolate that variable.
I don't plug in the A connector to isolate all that.

I plug the TCCM back into the B connector and it pops the the fuse again.
Can a bad TCCM cause a 25amp fuse to keep blowing?I physically inspected it out of its case and appears perfect.

Anyone have any ideas?





I only reconnect the AZ connector

52merc

I would say from your diagnostics that the TCCM has failed and needs to be replaced. Not that common.

HatinBrakeController

Swapped out TCCM now all is well

52merc

Thanks for the update. Glad you got it fixed.

Did you change your user name?