U0146–LOST COMMUNICATION WITH CENTRAL GATEWAY

For a complete wiring diagram Refer to Section 8W.

Set Condition:
If the Automatic Sway-Bar System Module either fails to receive bus messages from the Engine Control Module (ECM) for approximately 500 ms, or it receives invalid messages from the ECM, or it detects messages from the ECM are of improper data length.

Possible Causes

DTCs RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES

CAN C BUS CIRCUITS OPEN OR SHORTED

ECM POWER AND GROUND

ECM

AUTOMATIC SWAY-BAR SYSTEM (ASBS) MODULE

1.VERIFY DTC IS ACTIVE

NOTE: Ensure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.

Does this DTC reset?

Yes

The condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.
Perform ASBS VERIFICATION TEST. (Refer to 2 - SUSPENSION/ACTIVE CHASSIS - STANDARD PROCEDURE)

2.CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCs

NOTE: Check for CAN C hardware electrical, VIN Missing/Mismatch, battery or ignition related DTCs.

Does the scan tool display any active DTCs related to the conditions listed above?

Yes

Diagnose and repair the DTC(s). Refer to the Table of Contents in the applicable Section.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).

3.VERIFY THAT THE ECM IS ACTIVE ON THE BUS

Is the ECM active on the bus?

Yes

Perform the Stored Lost Communication test procedure.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).

4.CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCs

Is there more than one module with active DTCs “Logged Against” the ECM?

Yes

Replace/update the ECM in accordance with the service information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to BODY VERIFICATION TEST – VER 1).

Replace and program the Final Drive Control Module in accordance with Service Information.
Perform ASBS VERIFICATION TEST. (Refer to 2 - SUSPENSION/ACTIVE CHASSIS - STANDARD PROCEDURE)