C1437

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1437: Lost Communication with ECM
C1437 - Lost Communication with ECM

DESCRIPTION

The skid control ECU receives signals from the ECM via the CAN communication system.





WIRING DIAGRAM

Refer to DTCs U0073, U0100, U0123, U0124 and U0126 U Code Charts.

INSPECTION PROCEDURE

NOTICE:
When replacing the brake actuator assembly, perform zero point calibration Component Tests and General Diagnostics.

PROCEDURE

1. READ VALUE USING TECHSTREAM (EFI Communication Open)

(a) Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to the DTC Check For Intermittent Problems.

ABS/VSC/TRAC:





OK:

There are no momentary interruptions.

HINT
Perform the above inspection before removing the sensor and connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU - ECM)
OK -- Continue to next step.

2. RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Start the engine.

(d) Drive the vehicle at a speed of 15 km/h (9 mph) or more for 10 seconds or more.

(e) Check that no CAN communication system DTC is output CAN Communication System.

(f) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

Result:





D -- INSPECT CAN COMMUNICATION SYSTEM CAN Communication System

C -- INSPECT ENGINE CONTROL SYSTEM How to Proceed with Troubleshooting

B -- INSPECT ENGINE CONTROL SYSTEM How to Proceed with Troubleshooting

A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) How To Proceed With Troubleshooting

3. REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU - ECM)

(a) Turn the ignition switch off.

(b) Repair or replace the harness or connector.

(c) Check for any momentary interruption between the skid control ECU and the ECM Check For Intermittent Problems.

(d) Check that there is no momentary interruption.

NEXT -- Continue to next step.

4. RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Start the engine.

(d) Drive the vehicle at a speed of 15 km/h (9 mph) or more for 10 seconds or more.

(e) Check that no CAN communication system DTC is output CAN Communication System.

(f) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

Result:





C -- INSPECT CAN COMMUNICATION SYSTEM CAN Communication System

B -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

A -- END