Code No.C1201:
FR wheel speed sensor signal (signal short circuit)
Code No.C1206: FL wheel speed sensor
signal (signal short circuit)
Code No.C1211: RR wheel speed sensor signal (signal short
circuit)
Code No.C1216: RL wheel speed sensor signal (signal short circuit)
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- If there is any
problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis,
diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table
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- Before replacing the ECU, ensure that the communication circuit is normal.
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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 ABS-ECU. ABS-ECU
uses the frequency of the pulse signals to determine the wheel speed.
DIAGNOSIS CODE SET CONDITION
Diagnosis code No.C1201, C1206, C1211 or C1216 is set if any abnormal voltage from the
wheel speed sensor is detected without the outputs of code No.C1200, C1202, C1205, C1207, C1210,
C1212, C1215 or C1217.
PROBABLE CAUSES
Current trouble
- Damaged wiring harness and connectors
- Teeth lack or clogging of the ABS rotor
- Malfunction of the wheel bearing <Front>
- Malfunction of the axle hub assembly <Rear>
- Noise interference
- Wheel speed sensor malfunction
- ABS-ECU malfunction
Past trouble
- Carry out diagnosis with particular emphasis on wiring harness and
connector failures between ABS-ECU and the wheel speed sensor. For diagnosis procedures, refer
to How to treat past trouble (GROUP 00 - How to Cope with Intermittent Malfunctions ).
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STEP 1. M.U.T.-III CAN bus diagnosis
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Use M.U.T.-III to diagnose the CAN bus lines.
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Q.
Is the check result normal?
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 Go to Step 3.
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 Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
On completion, go to Step 2.
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STEP 2. Diagnosis code recheck after resetting CAN bus lines
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(1)Drive the vehicle at 30 km/h or more.
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(2)Turn the ignition switch from the "ON" position to the "LOCK" (OFF) position.
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Q.
Is diagnosis code No.C1201, C1206, C1211 or C1216 set?
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Go to Step 3.
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This diagnosis is complete.
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STEP 3. M.U.T.-III diagnosis code
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Check that diagnosis code No.C1200, C1202, C1205, C1207, C1210, C1212, C1215 or C1217
is also set.
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Q.
Is diagnosis code No.C1200, C1202, C1205, C1207, C1210, C1212, C1215 or C1217 also
set?
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Perform the diagnosis for diagnosis code No.C1200, C1202, C1205, C1207, C1210,
C1212, C1215 or C1217 (Refer to or ).
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Go to Step 4.
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STEP 4. M.U.T.-III data list
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Check the following data list (Refer to ).
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- Item No.01: FL wheel speed sensor
- Item No.02: FR wheel speed sensor
- Item No.03: RL wheel speed sensor
- Item No.04: RR wheel speed sensor
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Q.
Is the check result normal?
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Go to Step 11.
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Go to Step 5.
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STEP 5. Check for wheel speed sensor installation
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Check how the wheel speed sensor is installed correctly (Disconnection of wheel speed
sensor, loose mounting bolt, etc.).
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- Code No.C1201 is set: Wheel speed sensor (FR)
- Code No.C1206 is set: Wheel speed sensor (FL)
- Code No.C1211 is set: Wheel speed sensor (RR)
- Code No.C1216 is set: Wheel speed sensor (RL)
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Q.
Is the check result normal?
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Go to Step 6.
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Reinstall the wheel speed sensor correctly (Refer to ).
Then go to Step 12.
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STEP 6. Check for wheel speed sensor output current
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Refer to .
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- Code No.C1201 is set: Wheel speed sensor (FR)
- Code No.C1206 is set: Wheel speed sensor (FL)
- Code No.C1211 is set: Wheel speed sensor (RR)
- Code No.C1216 is set: Wheel speed sensor (RL)
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Q.
Is the check result normal?
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Go to Step 7.
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Replace the wheel speed sensor (Refer to ). Then
go to Step 12.
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STEP 7. Check the wheel bearing for looseness.
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If the wheel bearing are loose, the gap between the wheel speed sensor and ABS rotor may
become excessive. Check the wheel bearing, which diagnosis code indicates, for looseness.
Code No.C1201 is set
- Check the wheel bearing <FR> (Refer to GROUP 26 - On-vehicle
Service - Wheel bearing axial play check ).
Code No.C1206 is set
- Check the wheel bearing <FL> (Refer to GROUP 26 - On-vehicle
Service - Wheel bearing axial play check ).
Code No.C1211 is set
- Check the wheel bearing <RR> (Refer to GROUP 27 - On-vehicle
Service - Wheel bearing axial play check ).
Code No.C1216 is set
- Check the wheel bearing <RL> (Refer to GROUP 27 - On-vehicle
Service - Wheel bearing axial play check ).
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Q.
Is the check result normal?
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Go to Step 8.
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NO (front wheel bearing axial play is not within the standard value) : Replace the front wheel bearing (Refer to GROUP 26 - Front Axle Hub Assembly ).
Then go to Step 12.
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NO (rear wheel bearing axial play is not within the standard value) : Replace the rear wheel bearing (Refer to GROUP 27 - Rear Axle Hub Assembly ).
Then go to Step 12.
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STEP 8. Check of wheel speed detection encoder.
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Check the encoder, which diagnosis code indicates, for foreign material or deformation.
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Q.
Is the check result normal?
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Go to Step 9.
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NO <Encoder (FR, FL) abnormal> : If the encoder is contaminated with foreign material, clean it. If the wheel bearing
is deformed, replace it (Refer to GROUP 26 - Front Axle Hub Assembly ).
Then go to Step 12.
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NO <Encoder (RR, RL) abnormal> : If the pulse rotor is contaminated with foreign material, clean it. If the rear hub
assembly is deformed, replace it (Refer to GROUP 27 - Rear Axle Hub Assembly ).
Then go to Step 12.
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STEP 9. Voltage measurement at the ABS-ECU connector
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(1)Disconnect the ABS-ECU connector, front wheel speed sensor (RH) connector <C1201>,
front wheel speed sensor (LH) connector <C1206>, rear wheel speed sensor (RH) connector <C1211> or
rear wheel speed sensor (LH) connector <C1216>.
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(2)Turn the ignition switch to the ON position.
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(3)Measure the voltage between the ABS-ECU connector terminals.
Code No.C1200 is set
- Between FR- terminal and body earth
Code No.C1205 is set
- Between FL- terminal and body earth
Code No.C1210 is set
- Between RR- terminal and body earth
Code No.C1215 is set
- Between RL- terminal and body earth
OK: 1 V or less
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Q.
Is the check result normal?
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Go to Step 10.
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Repair the defective connector or the wiring harness. Then go to Step 12.
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STEP 10. Resistance measurement at the ABS-ECU connector
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(1)Disconnect the ABS-ECU connector, front wheel speed sensor (RH) connector <C1201>,
front wheel speed sensor (LH) connector <C1206>, rear wheel speed sensor (RH) connector <C1211> or
rear wheel speed sensor (LH) connector <C1216>.
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(2)Measure the resistance between the ABS-ECU connector terminals.
Code No.C1200 is set
- Between FR- terminal and body earth
Code No.C1205 is set
- Between FL- terminal and body earth
Code No.C1210 is set
- Between RR- terminal and body earth
Code No.C1215 is set
- Between RL- terminal and body earth
OK: No continuity
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Q.
Is the check result normal?
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Go to Step 11.
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Repair the defective connector or the wiring harness. Then go to Step 12.
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STEP 11. Check whether the diagnosis code is set again.
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(1)Drive the vehicle at 30 km/h or more.
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(2)Turn the ignition switch from the "ON" position to the "LOCK" (OFF) position.
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Q.
Is diagnosis code No.C1201, C1206, C1211 or C1216 set?
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Replace the hydraulic unit [(integrated with ABS-ECU) Refer to ].
Then go to Step 12.
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Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent
Malfunctions ).
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STEP 12. Check whether the diagnosis code is set again.
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(1)Drive the vehicle at 30 km/h or more.
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(2)Turn the ignition switch from the "ON" position to the "LOCK" (OFF) position.
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Q.
Is diagnosis code No.C1201, C1206, C1211 or C1216 set?
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Return to Step 1.
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This diagnosis is complete.
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