When the vehicle is turning with respect to a vertical axis the yaw rate sensor detects the yaw rate electroniclly 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 ESP 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.
It interchanges signals with HECU through extra CAN line which only used for communication between HECU and sensor.
A failure is detected if the Yaw rate & later G sensor message was not received or HECU detects sensor CAN Bus off state for more than the specified failure detection time. The Monitoring starts 1sec after Power Up.
Item | Detecting Condition | Possible cause | |
Case1 | DTC Strategy | ● Yaw rate & later G sensor message monitoring | ● Faulty Yaw Rate & Lateral G sensor ● Open or short of Yaw Rate & Lateral G sensor |
Enable Conditions | ● In case that Yaw rate & later G sensor message was not received for more than 500ms within normal voltage condition. - The Monitoring starts 1s after Power Up. | ||
Case2 | DTC Strategy | ● Open, short monitoring | |
Enable Conditions | ● In case sensor CAN BUS off state continued for more than 100ms. | ||
Fail Safe | ● Inhibit the ESP control and allow the ABS/EBD control. ● The ESP warning lamp is activated. | ||
Connect scantool to Data Link Connector(DLC).
Ignition "ON" & Engine "ON".
Monitor the "Lateral G Sensor, Yaw Rate Sensor" parameter on the Scantool.
Specification : Lateral G Sensor : approx. ± 0.0 G, YAW Rate Sensor :approx. ± 0.0 deg/s
Fig 1) Test Condition : Ignition "ON" & Engine "OFF".
Yaw Rate Sensor Normal Data
Fig 2) Test Condition : Ignition "ON" & Engine "OFF".
Lateral G Sensor Normal Data
Is parameter displayed within specifications?
 | ▶ Fault is intermittent caused by poor connection in Yaw Rate & Lateral G sensor harness and/or HECU's connector or was repaired and HECU memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure. |
 | ▶ Go to "Terminal and Connector Inspection" procedure. |
Many malfunctions in the electrical system are caused by poor harness(es) and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
| ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure. |
| ▶ Go to "Power Circuit Inspection" procedure. |
Ignition "ON" & Engine "OFF".
Measure voltage between power terminal of the Yaw Rate & Lateral G sensor harness connector and chassis ground.
Specification : Approx. 12V
Is the measured value within specifications?
| ▶ Go to "Ground Circuit Inspection" procedure. |
| ▶ Repair open or short in power circuit between the yaw rate & lateral G sensor harness connector and HECU harness connector and then, go to "Verification of vehicle Repair" If there is no problem in Power circuit, 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. |
Ignition "OFF" & Engine "OFF".
Disconnect yaw rate & lateral G sensor connector.
Measure resistance between ground terminal of the yaw rate & lateral G sensor harness connector and chassis ground.
Specification : Approx. below 1Ω
Is the measured value within specifications?
| ▶ Go to "Signal Circuit Inspection" procedure. |
| ▶ Repair open or short in ground circuit between the yaw rate & lateral G sensor harness connector and HECU harness connector and then, go to "Verification of vehicle Repair" |
Ignition "OFF" & Engine "OFF".
Disconnect yaw rate & lateral G sensor, HECU connector.
Measure resistance between CAN LOW terminal, CAN HIGH terminal of the yaw rate & lateral G sensor harness connector and chassis ground.
Specification : ∞ Ω
Is the measured value within specifications?
| ▶ Go to next procedure. |
| ▶ Repair short to ground in CAN signal circuit in case of abnormal resistance measured and then go to "Verification of vehicle Repair" procedure. |
Ignition "ON" & Engine "OFF".
Disconnect HECU connector.
Measure voltage between CAN LOW terminal, CAN HIGH terminal of the HECU harness connector and chassis ground.
Specification : Approx. 0 V
Is the measured value within specifications?
| ▶ Go to next procedure. |
| ▶ Repair short to battery in CAN signal circuit in case of abnormal voltage measured and then, go to "Verification of vehicle Repair" procedure. |
Ignition "OFF" & Engine "OFF".
Disconnect HECU connector.
Measure resistance between CAN LOW terminal and CAN HIGH terminal of the HECU connector.
Specification : Approx. 120 Ω
Is the measured value within specifications?
| ▶ Go to "Component Circuit Inspection" procedure. |
| ▶ 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. |
Ignition "OFF" & Engine "OFF".
Disconnect HECU connector.
Measure resistance between CAN LOW terminal and CAN HIGH terminal of the HECU harness connector.
Specification : Approx. 120 Ω
Is the measured value within specifications?
| ▶ Fault is intermittent caused by poor connection in yaw rate & lateral G sensor harness and/or HECU's connector. Go to "Verification of vehicle Repair" procedure. |
| ▶ In case of the resistance "approx. 1Ω" : Repair mutual short in CAN signal circuit of the yaw rate & lateral G sensor and then go to "Verification of vehicle Repair" procedure. In case of the resistance "∞ Ω" : Repair open in CAN signal circuit of the yaw rate & lateral G sensor and then go to "Verification of vehicle Repair" procedure. If there is no problem in CAN signal circuit, Substitute with a known-good yaw rate & lateral G sensorand check for proper operation. If problem is corrected, replace the yaw rate & lateral G sensor and then go to "Verification of Vehicle Repair" procedure. |
After a repair, it is essential to verify that the fault has been corrected.
Connect scantool and select "Diagnostic Trouble Codes(DTCs)" mode
Using a scantool, Clear DTC.
Operate the vehicle within DTC Detecting Condition in General Information.
Using a scantool, Check DTC present.
Are any DTCs present ?
| ▶ Go to the applicable troubleshooting procedure. |
| ▶ System performing to specification at this time. |
