C1200
DTC C1200 FL SENSOR-OPEN/SHORTDTC C1203 FR SENSOR-OPEN/SHORT
DTC C1206 RL SENSOR-OPEN/SHORT
DTC C1209 RR SENSOR-OPEN/SHORT
COMPONENT LOCATION:
GENERAL DESCRIPTION
The wheel speed sensor is the essential component the ABS ECU uses to calculate vehicle speed and to determine whether wheel lock occurs. For example, rear wheel speed signal is used as a reference value, for vehicle speed, in front wheel drive vehicles, and if a difference between front and rear wheel speed occurs, then ABS control is performed. Wheel speed sensor is an active hall-sensor type and good at temperature and noise characteristic. Digital wave is produced as tone wheel rotate according as hall sensor principle. Frequency of duty wave is changed in proportion to rotation of tone wheel and HECU calculate vehicle speed by this frequency.
DTC DESCRIPTION
The ABS ECU monitors the wheel speed sensor circuit continuously. If the sensor signal current is continuously out of the specified range for 200 msec, then the HECU determines that the circuit is open/short, and sets this code. Warning lamp is turned OFF if the detected fault is not more than when the IG KEY is turned to ON again, and wheel speeds are more than 10 Km/h (6 MPH).
DTC DETECTING CONDITION
DTC DETECTING CONDITION:
TERMINAL & CONNECTOR INSPECTION
Refer to DTC C1101. C1101
POWER SUPPLY CIRCUIT INSPECTION
1. Ignition "ON" & Engine "OFF".
2. Measure voltage between terminal 2 of the wheel speed sensor harness connector and chassis ground.
Specification: approximately B+
Is the measured voltage within specifications?
YES
- Go to Signal Circuit Inspection procedure.
NO
- Check for open or short to GND in wheel speed sensor harness between terminal 1 6(ESC:26),9,6,8 of the HECU harness connector and terminal 2 of the Wheel speed sensor harness connector. Repair as necessary and then go to Verification of vehicle Repair procedure.
SIGNAL CIRCUIT INSPECTION
1. Ignition "ON" & Engine "OFF".
2. By turning the wheel with hand.
3. Measure voltage between terminal 5,10,17(ESC:27),19(ESC:29) of the HECU harness connector and chassis ground.
Specification: High: 0.89 - 1.26 Volts, Low: 0.44 - 0.63 Volts
Is the measured voltage within specifications?
YES
- Go to Component Inspection procedure.
NO
- Check for open or short to GND in wheel speed sensor harness between terminal of the wheel speed sensor harness connector and terminal 5,10,17(ESC:27),19(ESC:29) 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. Start and drive vehicle in gear and maintain vehicle speed of approximately 10 km/h or more (6 mph or more).
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 wheel speed sensor harness, faulty wheel speed 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 scan tool and select Diagnostic Trouble Codes (DTCs) mode.
2. Using a scan tool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information. (Start and drive vehicle in gear and maintain vehicle speed of approximately 10 km/h or more (6 mph or more))
Are any DTCs present?
YES
- Go to the applicable troubleshooting procedure.
NO
- A system performs normally at this time.