Restraints

U0019-CAN B BUS

U0019 - Can B Bus:

WHEN MONITORED
Continuously

SET CONDITION
Whenever the CAN B Bus (+) or CAN B Bus (-) circuit is open, shorted to voltage, or shorted to ground.

POSSIBLE CAUSES
- Active U0019 CAN B BUS DTC in front control module
- (D55) CAN B BUS (+) circuit open
- (D54) CAN B BUS (-) circuit open
- Occupant restraint controller (ORC)

Diagnostic Test

1. VERIFY DTC U0019-CAN B BUS IS ACTIVE
Turn the ignition on.
With the scan tool, read Occupant Restraint Controller (ORC) DTCs.

Q: Does the scan tool display active: U0019-CAN B BUS?

YES: Go To 2
NO: If the DTC is stored, check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also, inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals.
Perform AIRBAG SYSTEM VERIFICATION TEST - VER 1. Airbag System Verification Test

2. CHECK FOR ACTIVE CAN B BUS RELATED DTCS IN THE FRONT CONTROL MODULE (FCM)
With the scan tool, read Front Control Module (FCM) DTCs

Q: Does the scan tool display any active CAN B BUS related DTCs?

YES: Diagnose and repair the DTC(s).
NO: Go To 3

3. CHECK (D55) CAN B BUS (+) CIRCUIT FOR AN OPEN




Turn the ignition off.
Disconnect the negative battery cable. Disconnect the ORC C2 connector.
Disconnect the Front Control Module (FCM) C1 connector.
Measure the resistance of the (D55) CAN B Bus (+) circuit between the Front Control Module C1 connector and the ORC C2 connector.

Q: Is the resistance below 2.0 ohms?

YES: Go To 4
NO: Repair the (D55) CAN B Bus (+) circuit for an open.
Perform AIRBAG SYSTEM VERIFICATION TEST - VER 1. Airbag System Verification Test

4. CHECK (D54) CAN B BUS (-) CIRCUIT FOR AN OPEN




Measure the resistance of the (D54) CAN B Bus (-) circuit between the Front Control Module C1 connector and the ORC C2 connector.

Q: Is the resistance below 2.0 ohms?

YES: Replace the ORC.
Perform AIRBAG SYSTEM VERIFICATION TEST - VER 1. Airbag System Verification Test
NO: Repair the (D54) CAN B Bus (-) circuit for an open.
Perform AIRBAG SYSTEM VERIFICATION TEST - VER 1. Airbag System Verification Test