Heated Seat Module (HSM)

U0019-CAN B BUS





For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

- When Monitored:
Continuously

- Set Condition:
This code sets if the (D55) Can B Bus (+) circuit or the (D54) Can B Bus (-) circuit is shorted to voltage or shorted to ground.





1. VERIFY DTC U0019-CAN B BUS IS ACTIVE
1. Turn the ignition on.
2. With the scan tool, record and erase DTCs.
3. Cycle the ignition three times ending with the ignition on.
4. With the scan tool, read DTCs.

Is DTC U0019-CAN B BUS active?

Yes

- Go To 2

No

- The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Look for chafed, pierced, pinched, or partially broken wires and broken, bent, pushed out, spread, corroded, or contaminated terminals.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK FOR CAN B BUS RELATED DTCs IN FRONT CONTROL MODULE (FCM)
1. With the scan tool, read FCM DTCs.

Are there any CAN B BUS related DTCs set in the Front Control Module (FCM)?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure.

No

- Go To 3

3. CHECK (D55) CAN B BUS (+) CIRCUIT FOR A SHORT TO VOLTAGE




1. Turn the ignition off.
2. Disconnect the HSM connector.
3. Disconnect the FCM C1 connector.
4. Turn the ignition on.
5. Measure the voltage of the (D55) Can B Bus (+) circuit between the HSM connector and ground.

Is the voltage above 10.0 volts?

Yes

- Repair the (D55) Can B Bus (+) circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. CHECK (D54) CAN B BUS (-) CIRCUIT FOR A SHORT TO VOLTAGE




1. Measure the voltage of the (D54) Can B Bus (-) circuit between the HSM connector and ground.

Is the voltage above 10.0 volts?

Yes

- Repair the (D54) Can B Bus (-) circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 5

5. CHECK (D55) CAN B BUS (+) CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Measure the resistance of the (D55) Can B Bus (+) circuit between ground and the HSM connector.

Is the resistance below 1000.0 Ohms?

Yes

- Repair the (D55) Can B Bus (+) circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 6

6. CHECK (D54) CAN B BUS (-) CIRCUIT FOR A SHORT TO GROUND




1. Measure the resistance of the (D54) Can B Bus (-) circuit between ground and the HSM connector.

Is the resistance below 1000.0 Ohms?

Yes

- Repair the (D54) Can B Bus (-) circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Heated Seat Module (HSM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.