U1001
U1001-CAN B BUS (-) CIRCUIT- MEMORY MIRROR MODULEU1001 - Can B Bus (-) Circuit - Memory Mirror Module:
WHEN MONITORED
Continuously
SET CONDITION
Whenever the Can B Bus (-) circuit is open, shorted to voltage or shorted to ground, this code will set.
POSSIBLE CAUSES
- CAN B BUS (-) DTC's in front control module
- (D54) CAN B BUS (-) circuit open
- Memory mirror module
Diagnostic Test
1.TEST FOR INTERMITTENT CONDITION
Turn the ignition on.
With the scan tool, record and erase DTC's
Cycle the ignition from on to off 3 times.
Turn the ignition on.
With the scan tool, read DTC's.
Q: Does the scan tool display U1001 CAN B BUS (-) CIRCUIT?
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 FRONT CONTROL MODULE DTC'S
With the scan tool, read Front Control Module DTC's
Q: Does the scan tool display any CAN B BUS DTC's - ACTIVE?
YES: Refer to the symptom list for problems related to Communication in the ELECTRICAL - ELECTRONIC CONTROL MODULES - ELECTRICAL DIAGNOSES.
NO: Go to 3
3. CAN B BUS (-) CIRCUIT OPEN
Turn the ignition off.
Disconnect the Front Control Module C1 connector.
Disconnect the appropriate Memory Mirror Module C1 connector.
Measure the resistance of the (D54) Can B Bus (-) circuit between the Front Control Module connector and the Memory Mirror Module connector.
Q: Is the the resistance below 2.0 ohms?
YES: Replace the Memory Mirror Module. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Repair the Can B Bus (-) circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test