Power Liftgate

U0019-CAN B BUS

For a complete wiring diagram refer to Diagrams/Electrical.

- When Monitored:

Continuously

- Set Condition:

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





Diagnostic Test

1. VERIFY DTC U0019-CAN B BUS IS ACTIVE

Turn the ignition on.

With the scan tool, read PLGM DTCs.

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 chaffed, pierced, pinched, and partially broken wires. Also, inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals.
- Perform BODY VERIFICATION TEST - VER 1. Body 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

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

Yes

- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

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 Power Liftgate Module C2 connector.

Disconnect the Front Control Module (FCM) C1 harness connector.

Measure the resistance of the (D55) CAN B Bus (+) circuit between the Front Control Module C1 harness connector and the Power Liftgate Module C2 connector.

Is the resistance below 2.0 ohms?

Yes

- Go To 4

No

- Repair the (D55) CAN B Bus (+) circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

4. CHECK (D54) CAN B BUS (-) CIRCUIT FOR A SHORT TO THE (D55) CAN B BUS (+) CIRCUIT





Measure the resistance between the (D54) CAN B Bus (-) circuit and the (D55) CAN B Bus (+) circuit in the Power Liftgate Module C2 harness connector.

Is the resistance below 2.0 ohms?

Yes

- Repair the (D54) CAN B Bus (-) circuit for a short to the (D55) CAN B Bus (+) circuit.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 5

5. 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 Power Liftgate Module C2 connector.

Is the resistance below 2.0 ohms?

Yes

- Go To 6

No

- Repair the (D54) CAN B Bus (-) circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

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





Turn the ignition on.

Measure the voltage of the (D54) CAN B Bus (-) circuit.

Is there any voltage present?

Yes

- Repair the (D54) CAN B Bus (-) circuit for a short to voltage.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 7

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





Turn the ignition on.

Measure the voltage of the (D55) CAN B Bus (+) circuit.

Is there any voltage present?

Yes

- Repair the (D55) CAN B Bus (+) circuit for a short to voltage.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 8

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





Turn the ignition off.

Measure the resistance between ground and the (D54) CAN B Bus (-) circuit.

Is the resistance below 100 ohms?

Yes

- Repair the (D54) CAN B Bus (-) circuit for a short to ground.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 9

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





Turn the ignition off.

Measure the resistance between ground and the (D55) CAN B Bus (+) circuit.

Is the resistance below 100 ohms?

Yes

- Repair the (D55) CAN B Bus (+) circuit for a short to ground.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Replace the Power Liftgate Module.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test