Brake System

Component Location





General Description

When the vehicle is turning with respect to a vertical axis the yaw rate sensor detects the yaw rate electronically by the vibration change of plate fork inside the yaw rate sensor. If yaw velocity reaches the specific velocity after it detects the vehicle' yawing, the ESC control is reactivated. The later G sensor senses vehicle's lateral G. A small element inside the sensor is attached to a deflectable leverarm by later G. Direction and magnitude of lateral G loaded to vehicle can be known with electrostatic capacity changing according to lateral G. The output voltage of the lateral G sensor is 2.5V when the vehicle is at a standstill. Only with lateral G sensor, the ESC can not be reactivated.

DTC Description

A lateral acceleration reference signal is calculated from the wheel speeds, the steering angle and the yaw rate signals to monitor the lateral acceleration sensor signal. The difference between the reference signal and the sensor signal is evaluated for failure detection. A yaw rate reference signal is calculated from the wheel speeds, the steering angle and the lateral acceleration signals to monitor the yaw rate sensor signal. The difference between the reference signal and the sensor signal, and the gradient of the measured sensor signal is evaluated for the failure detection. If the difference between estimated value and measured value of the sensor is larger than predefined value for predefined time, the failure is recognized.

DTC Detecting Condition





Terminal and Connector Inspection

1. Many malfunctions in the electrical system are caused by poor harness(es) and terminal conditions. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES
> Repair as necessary and then go to "Verification Of Vehicle Repair" procedure.
NO
> Go to "Power Circuit Inspection" procedure.

Power Circuit Inspection

1. Ignition "ON" & Engine "OFF".
2. Measure voltage between terminal "1, 2" of the Yaw Rate & Lateral G sensor harness connector and chassis ground.

Specification : Approx. 2.5 V





3. Is the measured voltage within specifications?
YES
> Go to "Ground Circuit Inspection" procedure.
NO
> Check for open or short in the Yaw Rate & Lateral G sensor harness between terminal "1, 2" of the Yaw Rate & Lateral G sensor harness connector and terminal "41, 9" of the HECU harness connector. Repair as necessary and then go to "Verification Of Vehicle Repair" procedure. If OK, go to "Component Inspection" procedure.
> If OK, Substitute with a known-good Yaw Rate & Lateral G sensor and check for proper operation. If problem is corrected, replace Yaw Rate & Lateral G sensor and then go to "Verification Of Vehicle Repair" procedure.

Ground Circuit Inspection

1. Ignition "OFF".
2. Disconnect Yaw Rate & Lateral G sensor connector.
3. Measure resistance between terminal "4" of the Yaw Rate & Lateral G sensor harness connector and chassis ground.

Specification : Approx. below 1Ohms





4. Is the measured resistance within specifications?
YES
> Go to "Component Inspection" procedure.
NO
> Check for open or short in the Yaw Rate & Lateral G sensor harness between terminal "4" of the Yaw Rate & Lateral G sensor harness connector and terminal "23" of the HECU harness connector. Repair as necessary and then go to "Verification Of Vehicle Repair" procedure.

Component Inspection

1. Ignition "OFF".
2. Engine "ON".
3. Does warning lamp remain On?
YES
> Substitute with a known-good HECU and check for proper operation. If problem is corrected, replace HECU and then go to "Verification Of Vehicle Repair" procedure.
NO
> Fault is intermittent caused by faulty Yaw Rate & Lateral G sensor and/or faulty HECU or was repaired and HECU memory was not cleared. Go to the applicable troubleshooting procedure.

Verification Of Vehicle Repair

After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode.
2. Using a scantool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information. (Start and drive vehicle in gear and maintain vehicle speed is approx. 40 km/h or more(24.9 mph or more))
4. Are any DTCs present ?
YES
> Go to the applicable troubleshooting procedure.
NO
> System performing to specification at this time.