Vehicle Stability Control System

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: U0073, U0100, U0123, U0126: Control Module Communication Bus OFF
U0126 - Lost Communication with Steering Angle Sensor Module

DESCRIPTION

The skid control ECU receives signals from the ECM, steering angle sensor, yaw rate and acceleration sensor (for separate type) and/or yaw rate and acceleration sensor (airbag sensor assembly) (for built-in type) via the CAN communication system.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

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

ABS/VSC/TRAC





Result:





HINT
Perform the above inspection before disconnecting any sensors or connectors.

B -- RECONFIRM DTC

C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- Continue to next step.

2. CHECK IF EACH SENSOR AND ECM CONNECTOR IS SECURELY CONNECTED

(a) Turn the ignition switch off.

(b) Check if each sensor or ECM connector is securely connected.

OK:

Each connector is securely connected.

NG -- CONNECT CONNECTOR TO EACH SENSOR OR ECM CORRECTLY
OK -- Continue to next step.

3. RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Record the output DTCs (for VSC system and/or CAN communication system) Reading and Clearing Diagnostic Trouble Codes for VSC system, or Diagnosis System for CAN communication system).

HINT
If CAN communication system DTCs and related sensor DTCs are output simultaneously, troubleshoot the DTCs (for VSC system) after the CAN communication system returns to normal.

Result:





B -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Vehicle Stability Control System

C -- INSPECT CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting

A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting

4. REPAIR OR REPLACE HARNESS OR CONNECTOR

(a) Turn the ignition switch off.

(b) Repair or replace the harness or connector.

(c) Check for any momentary interruptions between the skid control ECU and each sensor or ECM Check for Intermittent Problems.

NEXT -- Continue to next step.

5. RECONFIRM DTC

(a) Turn the ignition switch off.

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

(c) Turn the ignition switch off.

(d) Start the engine.

(e) Drive the vehicle at a speed of 15 km/h (9 mph) or more and turn the steering wheel to the right and left.

(f) Check that no CAN communication system DTC is output Diagnosis System.

(g) If VSC system DTCs are output, record them Reading and Clearing Diagnostic Trouble Codes.

Result:





HINT
The CAN communication system must be normal when performing troubleshooting for sensor DTCs (for VSC system).

B -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Vehicle Stability Control System

C -- INSPECT CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting

A -- END