U0023-CAN B BUS (+) CIRCUIT HIGH

For a complete wiring diagram Refer to Section 8W.

When Monitored:
Continuously
Set Condition:
The FCM detects the (D55) CAN B Bus (+) circuit is shorted to voltage.

Possible Causes

(D55) CAN B BUS (+) CIRCUIT SHORTED TO VOLTAGE

ANY CAN B BUS MODULE

FRONT CONTROL MODULE

Diagnostic Test

1.TEST FOR INTERMITTENT CONDITION

Does the scan tool display this DTC as active?

Yes

Go To 2

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 VOLTAGE

Is voltage above 10.0 volts?

Yes

Go To 3

Inspect the wiring and connectors for damage or shorted circuits. If ok, replace the Front Control Module in accordance with the service information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).

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

NOTE: When performing the above step, turn the ignition off (wait one minute) before disconnecting any module. When the module is disconnected turn the ignition on to check for a short to voltage.

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

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 wiring diagrams to assist in diagnosis.

Is the voltage above 10.0 volts with all the CAN B Bus modules disconnected?

Yes

Repair the (D55) CAN B Bus (+) circuit for a short to voltage.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).

Replace the module that when disconnected the short to voltage was eliminated, in accordance with the service information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).