[clinebarger]

Code Setting Conditions:

Key in the Crank or Run position; system voltage over 5.23v, valid communication between the TAC module and the PCM established, and the PCM detected Invalid or missing serial data messages for more than 0.83 second. The TAC module and the PCM communicate via a dedicated serial data circuit. This serial data circuit is separate from other serial data circuits on the vehicle. Accurate transmitting and receiving of serial data requires good circuit integrity, and also adequate system voltage. This code monitors the accuracy of the serial data transmitted between the TAC module and PCM. If the PCM detects a loss of data or invalid data, DTC U0107 sets.

Potential Causes:
Malfunctioning TAC Module
Improper TAC Module Power
Improper TAC Ground
Damaged UART Wiring

Test voltage backprobed at the TAC module C1 Blue connector terminal 7 Pink wire ignition power (key on and cranking).

Test terminal 15 Black wire for a good ground. If you have a poor ground.....Inspect/clean/secure ground G104 at rear end of left cylinder head. And G103 at top rear of engine next to inboard edge of the right cylinder head.

Inspect the serial data wires pin 12 Orange/Black and pin 13 Dark Blue/White between the TAC module connector C1 and PCM connector C1. These are dedicated Universal Asynchronous Receive Transmit (UART) serial data lines.