U0022

U0022-CAN B BUS (+) CIRCUIT LOW

U0022 - Can B Bus (+) Circuit Low:

WHEN MONITORED
Continuously.

SET CONDITION
The TIPM detects the (D55) CAN B Bus (+) circuit is shorted to ground.

POSSIBLE CAUSES
- (D55) CAN B BUS (+) circuit shorted to ground
- Any CAN B BUS module
- Totally integrated power module

1. TEST FOR INTERMITTENT CONDITION

Turn the ignition on.
With the scan tool, record and erase TIPM DTC's.
Cycle the ignition from on to off 3 times.
Turn the ignition on.
With the scan tool, read active TIPM DTC s.

Q: 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 (D55) CAN B BUS (+) CIRCUIT FOR A SHORT TO GROUND

Turn the ignition off.
Disconnect the Totally Integrated Power Module C3 harness connector.
Measure the resistance between ground and the (D55) CAN B Bus (+) circuit.

Q: Is resistance below 1000.0 ohms?

YES: Go To 3
NO: Inspect the wiring and connectors for damage or shorted circuits. If ok, replace the Totally Integrated Power Module. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test




3. (D55) CAN B BUS (+) CIRCUIT SHORTED TO GROUND

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

NOTE:
- This is to determine if the short to ground is internal within a module or if the circuit is shorted.
- 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.

Q: 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 ground. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace the module that when disconnected the short to ground was eliminated,. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test