Test Q

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

Test Q1-Q3:

Test Q3-Q7:

Test Q7-Q11:

Test Q11-Q13:

Test Q14-Q17:

Test Q18:

Normal Operation
The climate controlled seat modules, driver seat module (DSM), vehicle security module, and the four-wheel drive (4WD) control module communicate with the diagnostic tool through the UBP communications network circuit 693 (OG). If circuit 693 (OG) becomes open or shorted to ground, communications to that module will not be possible. Check circuit 693 (OG) between the driver climate controlled seat module, passenger climate controlled seat module, DSM, vehicle security module, and the 4WD control module and the DLC C251. Total resistance values must not be more than 5 ohms. If the resistance is more than 5 ohms, there is an open in circuit 693 (OG), damage to the DLC C251, a problem in one of the in-line connectors or an internal/connector problem with one of the network modules. If, after individual checks of each circuit leading to a module show resistance values less than 5 ohms and no in-line connector issues present, the data link diagnostics test must be run with the module in question disconnected. If the data links diagnostics test passes with the module in question disconnected, it is the source of the concern and should be removed and a new module installed.

Possible Causes
- DLC C251
- UBP circuit 693 (OG) open, shorted to power or ground
- driver climate controlled seat module
- passenger climate controlled seat module
- vehicle security module
- DSM
- 4WD control module
- instrument cluster