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Code No. C1200 FR wheel speed sensor
Code No. C1205 FL wheel speed sensor
Code No. C1210 RR wheel speed sensor
Code No. C1215 RL wheel speed sensor
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
  • When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor and the G and yaw rate sensor (Refer to and ).
 
 
OPERATION
  • The wheel speed sensor is a kind of a pulse generator. It consists of encoders (a plate on which north and south pole sides of the magnets are arranged alternately) for detecting the wheel speed which rotates at the same speed of the wheels and wheel speed sensors. This sensor outputs frequency pulse signals in proportion to the wheel speed.
  • The pulse signals, which the wheel speed sensor creates, are sent to ASC-ECU. ASC-ECU uses the frequency of the pulse signals to determine the wheel speed.
 
 
DIAGNOSTIC TROUBLE CODE SET CONDITIONS
The ASC-ECU monitors the voltage fluctuation in each wheel speed sensor circuit. If ASC-ECU detects the open or short circuit in the circuit, it will store a diagnostic trouble code.
 
 
PROBABLE CAUSES
Current trouble
  • Damaged harness wires and connectors
  • Malfunction of the wheel speed sensor
  • Malfunction of the hydraulic unit (integrated with ASC-ECU)
  • Noise interference
Past trouble
  • Carry out diagnosis with particular emphasis on wiring harness and connector failures between ASC-ECU and the wheel speed sensor. For diagnosis procedures, refer to How to treat past trouble (GROUP 00 - How to Use Troubleshooting/Inspection Service Points ).
 
 
DIAGNOSIS
Required Special Tools:
  • MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite main harness A
  • MB992747: V.C.I.-Lite USB cable short
  • MB992748: V.C.I.-Lite USB cable long
  • MB991958: Scan Tool (M.U.T.-III Sub Assembly)
    • MB991824: Vehicles Communication Interface (V.C.I.)
    • MB991827: M.U.T.-III USB Cable
    • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
Use the scan tool MB991958 to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 3.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.
 
STEP 2. Diagnostic trouble code recheck after resetting CAN bus lines
(1) Drive the vehicle at 20 km/h (12 mph) or more and stop the vehicle.
(2) Turn the ignition switch from the "ON" position to the "LOCK" (OFF) position.
(3) Connect the scan tool and turn the ignition switch to the "ON" position.
Is diagnostic trouble code No. C1200, C1205, C1210 or C1215 set?
Go to Step 3.
This diagnosis is complete.
 
STEP 3. Using scan tool MB991958, check data list
Check the following service data (Refer to ).
  • (When code No. C1200 is set) Item 02: FR wheel speed sensor
  • (When code No. C1205 is set) Item 01: FL wheel speed sensor
  • (When code No. C1210 is set) Item 04: RR wheel speed sensor
  • (When code No. C1215 is set) Item 03: RL wheel speed sensor
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Go to Step 4.
 
STEP 4. Measure the voltage at the ASC-ECU connector (Short circuit to power supply).
(1) Connector check: ASC-ECU connector and wheel speed sensor connectors
(2) Disconnect the connector and measure at the wiring harness side.
(3) Ignition switch: "ON"
(4) Measure the voltage between the power supply terminal as well as signal terminal of each wheel speed sensor and body ground.
 
Diagnostic trouble code No. Checking terminal
Power supply terminalSignal terminal
C1200FR+FR-
C1205FL+FL-
C1210RR+RR-
C1215RL+RL-
OK: 1 V or less
Is the check result normal?
Go to Step 5.
(No. C1200 NG) : Go to Step 6.
(No. C1205 NG) : Go to Step 7.
(No. C1210 NG) : Go to Step 8.
(No. C1215 NG) : Go to Step 9.
 
STEP 5. Measure the resistance at the ASC-ECU connector (Short circuit to ground).
(1) Disconnect the connector and measure at the wiring harness side.
(2) Measure the resistance between the power supply terminal as well as signal terminal of each wheel speed sensor and body ground.
 
Diagnostic trouble code No. Checking terminal
Power supply terminalSignal terminal
C1200FR+FR-
C1205FL+FL-
C1210RR+RR-
C1215RL+RL-
OK: No continuity
Is the check result normal?
Go to Step 10.
(No. C1200 NG) : Go to Step 6.
(No. C1205 NG) : Go to Step 7.
(No. C1210 NG) : Go to Step 8.
(No. C1215 NG) : Go to Step 9.
 
STEP 6. Check the wiring harness wires between the ASC-ECU connector FR (+) or FR (-) terminal and the front wheel speed sensor (RH) connector terminal.
Check the front wheel speed sensor (RH) circuit for short to power supply or ground.
Is the check result normal?
Replace the front wheel speed sensor (RH) (Refer to ).
Repair the connector(s) and wiring harness.
 
STEP 7. Check the wiring harness wires between the ASC-ECU connector FL (+) or FL (-) terminal and the front wheel speed sensor (LH) connector terminal.
Check the front wheel speed sensor (LH) circuit for short to power supply or ground.
Is the check result normal?
Replace the front wheel speed sensor (RH) (Refer to ).
Repair the connector(s) and wiring harness.
 
STEP 8. Check the wiring harness wires between the ASC-ECU connector RR (+) or RR (-) terminal and the rear wheel speed sensor (RH) connector terminal.
Check the rear wheel speed sensor (RH) circuit for short to power supply or ground.
Is the check result normal?
Replace the front wheel speed sensor (RH) (Refer to ).
Repair the connector(s) and wiring harness.
 
STEP 9. Check the wiring harness wires between the ASC-ECU connector RL (+) or RL (-) terminal and the rear wheel speed sensor (LH) connector terminal.
Check the rear wheel speed sensor (LH) circuit for short to power supply or ground.
Is the check result normal?
Replace the front wheel speed sensor (RH) (Refer to ).
Repair the connector(s) and wiring harness.
 
STEP 10. Voltage and current measurement at each wheel speed sensors connector (Open circuit).
(1) Disconnect the wheel speed sensor connector, and measure at the wiring harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between the power supply terminal of each wheel speed sensors and the body ground.
(4) Measure the output current at the special tool test harness (MB991709) to connect between the wheel speed sensor-side connector and the wiring harness connector (Refer to ).
OK:
  • <Voltage> System voltage
  • <Current> 5 - 9 milliamperes or 11 - 17 milliamperes
Is the check result normal?
Go to Step 15.
[Front wheel speed sensor (RH)] : Go to Step 11.
[Front wheel speed sensor (LH)] : Go to Step 12.
[Rear wheel speed sensor (RH)] : Go to Step 13.
[Rear wheel speed sensor (LH)] : Go to Step 14.
 
STEP 11. Check the wiring harness wires between the ASC-ECU connector FR (+) or FR (-) terminal and the front wheel speed sensor (RH) connector terminal.
Check the front wheel speed sensor (RH) circuit for open.
Is the check result normal?
Go to Step 15.
Repair the wiring harness.
 
STEP 12. Check the wiring harness wires between the ASC-ECU connector FL (+) or FL (-) terminal and the front wheel speed sensor (LH) connector terminal.
Check the front wheel speed sensor (LH) circuit for open.
Is the check result normal?
Go to Step 15.
Repair the wiring harness.
 
STEP 13. Check the wiring harness wires between the ASC-ECU connector RR (+) or RR (-) terminal and the rear wheel speed sensor (RH) connector terminal.
Check the rear wheel speed sensor (RH) circuit for open.
Is the check result normal?
Go to Step 15.
Repair the wiring harness.
 
STEP 14. Check the wiring harness wires between ASC-ECU connector RL (+) or RL (-) terminal and the rear wheel speed sensor (LH) connector terminal.
Check the rear wheel speed sensor (LH) circuit for open.
Is the check result normal?
Go to Step 15.
Repair the wiring harness.
 
STEP 15. Check the wheel speed sensor.
Refer to .
Is the check result normal?
Go to Step 16.
Replace the wheel speed sensor (Refer to ).
 
STEP 16. Diagnostic trouble code recheck
Check again if the diagnostic trouble code is set.
(1) Erase the diagnostic trouble code.
(2) Ignition switch: "LOCK" (OFF) position to "ON"
(3) Drive the vehicle until the vehicles speed reaches 20 km/h (12 mph).
(4) Stop the vehicle.
(5) Turn the ignition switch from the "ON" position to the "LOCK" (OFF) position.
Is diagnostic trouble code No. C1200, C1205, C1210 or C1215 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).