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 lateral G sensor senses vehicle's lateral G. A small element inside the sensor is attached to a deflectable leverarm by lateral 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 failure is detected if the lateral acceleration sensor or yaw rate sensor signal stays in the fault range longer than the specified failure detection time. The Monitoring starts 1sec after Power Up.

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 "3" of the Yaw Rate & Lateral G sensor harness connector and chassis ground.

Specification : Approx. 5 V





3. Is the measured voltage within specifications?
YES
> Go to "Ground Circuit Inspection" procedure.
NO
> Check for open or short to GND in the Yaw Rate & Lateral G sensor harness between terminal "3" of the Yaw Rate & Lateral G sensor harness connector and terminal "36" of the HECU harness connector. Repair as necessary and then go to "Verification Of Vehicle Repair" procedure. If OK, go to "Component Inspection" 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 next 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.

Signal 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 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 "1, 2" of the Yaw Rate & Lateral G sensor harness connector and terminal "9, 41" 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.

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 open or short of Yaw Rate & Lateral G sensor harness and/or faulty Yaw Rate & Lateral G sensor 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.
4. Are any DTCs present ?
YES
> Go to the applicable troubleshooting procedure.
NO
> System performing to specification at this time.