Code No. C1202:
FR wheel speed sensor power circuit (malfunction power circuit)
Code No. C1207: FL
wheel speed sensor power circuit (malfunction power circuit)
Code No. C1212: RR wheel
speed sensor power circuit (malfunction power circuit)
Code No. C1217: RL wheel speed
sensor power circuit (malfunction power circuit)
| caution |
- 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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- Whenever ECU is replaced, ensure that the CAN bus lines are normal.
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OPERATION
- A toothed rotor (for wheel speed detection) generates
a voltage pulse as it moves across the pickup field of each wheel speed sensor.
- The wheel speed sensor transmit the frequency of the pulses to the ABS-ECU.
- The hydraulic unit assembly (integrated with ABS-ECU) modulates the amount of braking force
individually applied to each wheel cylinder.
DIAGNOSIS CODE SET CONDITIONS
- Irregular change in the wheel speed sensor voltage
- Wheel speed sensor voltage continuously indicates low value.
PROBABLE CAUSES
Current trouble
- Damaged wiring harness and connectors
- Malfunction of the wheel speed sensor
- Malfunction of the hydraulic unit assembly (integrated with ABS-ECU)
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)Turn the ignition switch to the "ON" position.
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(2)Turn the ignition switch to the "LOCK" (OFF) position.
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(3)Drive the vehicle at 15 km/h or more.
| note |
The ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 15 km/h
or higher.
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(4)Erase the diagnosis code.
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Q.
Is diagnosis code No. C1202, C1207, C1212 or C1217 set?
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Go to Step 3.
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The procedure is complete.
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STEP 3. M.U.T.-III diagnosis code
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Check that diagnosis codes No. C1200, C1205, C1210, and C1215 are also set.
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Q.
Are diagnosis codes No. C1200, C1205, C1210 and C1215 also set?
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Follow the diagnosis procedure for diagnosis code No. C1200, C1205, C1210 or C1215
(Refer to ).
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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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- (When code No. C1202 is set) Item 02: FR wheel speed sensor
- (When code No. C1207 is set) Item 01: FL wheel speed sensor
- (When code No. C1212 is set) Item 04: RR wheel speed sensor
- (When code No. C1217 is set) Item 03: RL wheel speed sensor
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Q.
Is the check result normal?
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Go to Step 8.
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Go to Step 5.
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STEP 5. Voltage measurement at the ABS-ECU connector
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(1)Disconnect the ABS-ECU connector, front wheel speed sensor (RH) connector <C1202>,
front wheel speed sensor (LH) connector <C1207>, rear wheel speed sensor (RH) connector <C1212>,
rear wheel speed sensor (LH) connector <C1217>.
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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.C1202 is set
- Between FR+
terminal and body earth
Code No.C1207 is set
- Between FL+
terminal and body earth
Code No.C1212 is set
- Between RR+
terminal and body earth
Code No.C1217 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 6.
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Repair the defective connector or the wiring harness. Then go to Step 9.
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STEP 6. Resistance measurement at the ABS-ECU connector
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(1)Disconnect the ABS-ECU connector, front wheel speed sensor (RH) connector <C1202>,
front wheel speed sensor (LH) connector <C1207>, rear wheel speed sensor (RH) connector <C1212>,
rear wheel speed sensor (LH) connector <C1217>.
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(2)Measure the resistance between the ABS-ECU connector terminals.
Code No.C1202 is set
- Between FR+
terminal and body earth
Code No.C1207 is set
- Between FL+
terminal and body earth
Code No.C1212 is set
- Between RR+
terminal and body earth
Code No.C1217 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 7.
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Repair the defective connector or the wiring harness. Then go to Step 9.
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STEP 7. Check for wheel speed sensor as a single unit
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Refer to .
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Q.
Is the check result normal?
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Go to Step 8.
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Replace the wheel speed sensor (Refer to ). Then
go to Step 9.
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STEP 8. Check whether the diagnosis code is set again.
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(1)Turn the ignition switch to the "ON" position.
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(2)Turn the ignition switch to the "LOCK" (OFF) position.
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(3)Drive the vehicle at 15 km/h or more.
| note |
The ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 15 km/h
or higher.
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(4)Erase the diagnosis code.
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Q.
Is diagnosis code No. C1202, C1207, C1212 or C1217 set?
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Replace the hydraulic unit assembly (integrated with ABS-ECU) (Refer to ). Then
go to Step 9.
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Intermittent malfunction (Refer to GROUP 00 -
How to Cope with Intermittent
Malfunctions ).
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STEP 9. Check whether the diagnosis code is set again.
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(1)Turn the ignition switch to the "ON" position.
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(2)Turn the ignition switch to the "LOCK" (OFF) position.
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(3)Drive the vehicle at 15 km/h or more.
| note |
The ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 15 km/h
or higher.
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(4)Erase the diagnosis code.
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Q.
Is diagnosis code No. C1202, C1207, C1212 or C1217 set?
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Return to Step 1.
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This diagnosis is complete.
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