Test J: No Universal Asynchronous Receiver-Transmitter (UART)-Based Protocol (UBP) Network Communication

PINPOINT TEST J: NO UNIVERSAL ASYNCHRONOUS RECEIVER-TRANSMITTER (UART)-BASED PROTOCOL (UBP) NETWORK COMMUNICATION

J1:

J2-J5:

J6-J9:

J10-J12:

J13-J15:

Normal Operation
The electronic automatic temperature control (EATC) module and vehicle security module communicate with the scan tool through the UBP communications network, circuit 693 (OG). The instrument cluster does not communicate with the scan tool on circuit 693 (OG), but does communicate with the EATC and vehicle security module on this circuit.

Possible Causes
- Circuit 693 (OG) open, short to ground or voltage (UBP communications network)
- Vehicle security module C2113c
- Vehicle security module
- EATC module C228b
- EATC module
- Instrument cluster C220b
- Instrument cluster