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

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

J1-J2:

J3-J6:

J7-J11:

J11-J13:

J14-J15:

Normal Operation
The vehicle security module, the electronic automatic temperature control (EATC) module and the instrument cluster all communicate with the diagnostic tool through the UBP communications network, circuit 693 (OG). Check circuit 693 (OG) between all modules and the data link connector (DLC) C251. The total resistance value must not be more than 5 ohms. If the resistance is more than 5 ohms there is an open in the UBP communications network circuit, damage to the DLC C251, damage to one of the module connectors, or a problem in an in-line connector.

Possible Causes
- UBP communications network, circuit 693 (OG) open, short to ground, or short to voltage
- DLC C251
- vehicle security module C2113c
- vehicle security module
- EATC module C228b
- EATC module
- instrument cluster C220b
- instrument cluster