CAN B BUS OCM

U0019-CAN B BUS-OCM

U0019 - CAN B Bus - OCM:

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 classification module (OCM)

Diagnostic Test

1. VERIFY DTC U0019-CAN B BUS-OCM IS ACTIVE

Turn the ignition on.
With the scan tool, read Occupant Classification Module (OCM) DTCs.

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

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

WARNING:
- TO AVOID PERSONAL INJURY OR DEATH, TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND WAIT TWO MINUTES BEFORE PROCEEDING.
- IF THE OCCUPANT CLASSIFICATION MODULE IS DROPPED AT ANY TIME, IT MUST BE REPLACED. FAILURE TO TAKE THE PROPER PRECAUTIONS CAN RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND PERSONAL INJURY OR DEATH.

Disconnect the OCM C1 connector.

NOTE: Check connectors - Clean and repair as necessary.

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 OCM C1 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 OCS VERIFICATION TEST - VER 1. OCS 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 OCM, C1 connector.

Q: Is the resistance below 2.0 ohms?

YES: Replace the OCM. Perform OCS VERIFICATION TEST - VER 1. OCS Verification Test
NO: Repair the (D54) CAN B Bus (-) circuit for an open. Perform OCS VERIFICATION TEST - VER 1. OCS Verification Test