P1781 code, How to fix it? [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: P1781 code, How to fix it?


justinp95
12-12-2007, 10:38 AM
I saw this on EFI live while doing my tune and heres what it said. "TCM MIL request circut" and it says "$10 Powertrain control module (PCM)". Does anyone know anything about this? Is the part $10? LOL.

Machinator
12-13-2007, 11:08 AM
It means the TCM has requested the ECM turn on the MIL light because the transmission has set a code(s). The TCM codes are seperate from the ECM codes.

dutch
12-18-2007, 09:18 PM
It means the TCM has requested the ECM turn on the MIL light because the transmission has set a code(s). The TCM codes are seperate from the ECM codes.

Just scanned mine and has this code. Does it mean that the TCM has separate codes?
Or what needs fixed?

Thanks.