U0025

U0025-CAN B BUS (-) CIRCUIT LOW





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

- When Monitored:
Continuously.

- Set Condition:
The Totally Integrated Power Module (TIPM) detects the (D54) CAN B Bus (-) circuit is shorted to ground.





1. TEST FOR INTERMITTENT CONDITION

NOTE: Check for any TSB(s) related to the condition. If a TSB applies, perform the procedure outlined in the TSB before continuing.

1. Turn the ignition on.
2. With the scan tool, record and erase TIPM DTCs.
3. Cycle the ignition from on to off 3 times.
4. Turn the ignition on.
5. With the scan tool, read active TIPM DTCs.

Does the scan tool display this DTC as 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.

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




1. Turn the ignition off.
2. Disconnect the Totally Integrated Power Module C3 harness connector.
3. Measure the resistance between ground and the (D54) CAN B Bus (-) circuit.

Is resistance below 1000.0 ohms?

Yes

- Go To 3

No

- Go To 4

3. (D54) CAN B BUS (-) CIRCUIT SHORTED TO GROUND




1. Measure the resistance between ground and the (D54) CAN B Bus (-) circuit.
2. While monitoring the ohmmeter, disconnect each CAN B Bus module one at a time.

NOTE: This is to determine if the circuit is shorted to ground internally within a module or if the circuit is shorted to ground in the harness.

NOTE: Disconnecting an in-line connector can eliminate a module or group of modules from the list of possible causes for this fault. Refer to the wring diagrams to assist in diagnosis.

Is resistance below 1000.0 ohms with all the CAN B Bus modules disconnected?

Yes

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

No

- Replace the module that when disconnected eliminated the short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

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




1. Measure the resistance between the (D55) CAN B Bus (+) circuit and (D54) CAN B Bus (-) circuit.

Is resistance below 1000.0 ohms?

Yes

- Go To 5

No

- Inspect the wiring and connectors for damage or shorted circuits. If ok, replace the Totally Integrated Power Module.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. (D55) CAN B BUS (+) CIRCUIT SHORTED TO THE (D54) CAN B BUS (-) CIRCUIT




1. Measure the resistance between the (D55) CAN B Bus (+) circuit and (D54) CAN B Bus (-) circuit.
2. While monitoring the ohmmeter, disconnect each CAN B Bus module one at a time.

NOTE: This is to determine if the short together is internal within a module or if the circuits are shorted together.

NOTE: Disconnecting an in-line connector can eliminate a module or group of modules from the list of possible causes for this fault. Refer to the wring diagrams to assist in diagnosis.

Is resistance below 1000.0 ohms with all the CAN B Bus modules disconnected?

Yes

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

No

- Replace the module that when disconnected the short together was eliminated,.
- Perform the BODY VERIFICATION TEST. Body Verification Test.