3.
Monitor the "Yaw rate sensor-lateral ＆ Yaw rate sensor-yaw" parameter on the Scantool.
Specification : Lateral G sensor : ± 0 G, YAW rate Sensor : ± 0 deg/s
Both the yaw-rate sensor and later G sensor is installed in lower floor. The yaw-rate sensor detecting the rotation angular velocity calculates a difference with a target amount of turing, the lateral G sensor detecting slip of the vehicle compensates a target amount of turning. 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 2.5 V when the vehicle is at a standstill.
The HECU monitors a signal voltage of either yaw-rate sensor or later G sensor to detect open or short to battery or short to ground. A failure is detected if the lateral acceleration sensor or yaw rate sensor signal voltage stays in the fault range longer than the 100 ms or the lateral acceleration sensor or yaw rate sensor reference voltage stays in the fault range longer than the 200 ms, or the self test form is against specification during self test.
Item | Detecting Condition | Possible cause | |
Case 1 | DTC Strategy | ● Voltage Monitoring | ● Faulty Yaw Rate ＆ Lateral G sensor ● Open or short of Yaw Rate ＆ Lateral G sensor ● Faulty HECU |
Monitoring Period | ● Continous | ||
Enable Conditions | ● A line fault is detected if V[LG] ＜ 0.3 V or V[LG] ＞ 4.7 V for a time t ＞= 100ms. ● A line fault is detected if V[YAW] ＜ 0.225 V OR V[YAW] ＞ 4.774 V for a time t ＞= 100 ms. ● A line fault is detected if V[YAW REFERENCE] ＜ 2.1 V OR V[YAW REFERENCE] ＞ 2.9 V for a time t ＞= 200 ms. | ||
Case 2 | DTC Strategy | ● Selftest Monitoring | |
Monitoring Period | ● Once after power up and no low voltage. | ||
Enable Conditions | ● A line fault is detected if 0.2 V ＜ V[LG] ＜ 0.8 V isn't continued for a time t ＞= 60 ms during POS (POS : power on selftest) | ||
Fail Safe | ● Reduced controller function. ● Inhibit the ESP control and allow the ABS/EBD control. ● The ESP warning lamps are activated.. | ||
Connect scantool to Data Link Connector(DLC).
Ignition "ON".
Monitor the "Yaw rate sensor-lateral ＆ Yaw rate sensor-yaw" parameter on the Scantool.
Specification : Lateral G sensor : ± 0 G, YAW rate Sensor : ± 0 deg/s
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 "W/Harness Inspection" procedure.
Many malfunctions in the electrical system are caused by poor harness(es) and terminals. 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 terminal "1" of the Yaw Rate ＆ Lateral G sensor harness connector and chassis ground.
Specification : Approx. B+
Is the measured voltage within specifications?
▶ Go to "Ground Circuit Inspection" procedure.
▶ Check for open or short to GND in the Yaw Rate ＆ Lateral G sensor harness between terminal "1" of the Yaw Rate ＆ Lateral G sensor harness connector and battery +. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
Ignition "OFF".
Disconnect Yaw Rate ＆ Lateral G sensor connector.
Measure resistance between terminal "4" of the Yaw Rate ＆ Lateral G sensor harness connector and chassis ground.
Specification : Approx. below 1Ω
Is the measured resistance within specifications?
▶ Go to "Signal Circuit Inspection" procedure.
▶ 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 chassis ground. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
Ignition "ON" ＆ Engine "OFF".
Measure voltage between terminal "3,5,6" of the Yaw Rate ＆ Lateral G sensor harness connector and chassis ground.
Specification : Approx. 2.5 V ( Voltage between terminal "5, 6" of the Yaw Rate ＆ Lateral G sensor harness connector and chassis ground.)
Is the measured resistance within specifications?
▶ Go to "Self Test Circuit Inspection" procedure.
▶ Check for open or short in the Yaw Rate ＆ Lateral G sensor harness between terminal "3, 5, 6" of the Yaw Rate ＆ Lateral G sensor harness connector and terminal "16, 18, 20" of thechassis ground. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
▶ If OK, Substitute with a known-good Yaw Rate ＆ Lateral G sensor and check for proper operation. If problem is corrected, replace sensor and then go to "Verification of Vehicle Repair" procedure.
Measure wave between terminal "2" of the Yaw Rate ＆ Lateral G sensor harness connector and chassis ground.
Specification : Approx. 0.2V ＜ Voltage ＜ 0.8V (during Ignition "ON")
Is the measured wave within specifications?
▶ Go to "Component Inspection" procedure.
▶ Check for open or short to GND in the Yaw Rate ＆ Lateral G sensor harness between terminal "2" of the Yaw Rate ＆ Lateral G sensor harness connector and terminal "37" of thechassis ground. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
▶ If OK, Substitute with a known-good Yaw Rate ＆ Lateral G sensor and check for proper operation. If problem is corrected, replace sensor and then go to "Verification of Vehicle Repair" procedure.
Ignition "OFF".
Engine "ON".
Does warning lamp remain On?
▶ 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.
▶ Fault is intermittent caused by poor connection in Yaw Rate & Lateral G sensor circuit and/or faulty Yaw Rate & Lateral G sensor or was repaired and HECU memory was not cleared. Go to the applicable troubleshooting 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.
Are any DTCs present ?
▶ Go to the applicable troubleshooting procedure.
▶ System performing to specification at this time.
