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DESCRIPTION
The speed sensors detect
wheel speed and transmit the signals to the ECU. These signals are used for
control of the ABS
control system. Each of the front and rear rotors has 48 serrations. When the
rotors
rotate, the magnetic field
generated by the permanent magnet in the speed sensor induces an AC
voltage.
Since the frequency of this AC voltage changes in direct proportion to the speed
of the rotor, the
frequency is used by the
ECU to detect the speed of each wheel.
When foreign matter adheres to the speed sensor tip or speed sensor rotor, or
the rotor teeth are chipped,
these DTCs are
output. An abnormal waveform input from the sensor determines these conditions.
These DTCs may be detected when a malfunction occurs in the connector terminals
or wire harness of
the speed sensor circuit.
DTCs C1275 to
C1278 can be deleted when the speed sensor sends a vehicle speed signal or
the
Test Mode ends. DTCs from
C1275 to C1278 are output only in the Test Mode.
| DTC Code | Diag Code | DTC Detection Condition | Trouble Area |
| C1235 C1236 C1238 C1239 |
35 36 38 39 |
When either of the
following is detected:
|
• Speed sensor • Speed sensor rotor • Sensor installation • Skid control ECU |
| C1275 C1276 C1277 C1278 |
75 76 77 78 |
Detected only during Test Mode. | • Speed sensor • Speed sensor rotor |
• DTCs C1235 and C1275 are for the front speed sensor RH.
• DTCs C1236 and C1276 are for the front speed sensor LH.
• DTCs C1238 and C1277 are for the rear speed sensor RH.
• DTCs C1239 and C1278 are for the rear speed sensor LH.
WIRING DIAGRAM
INSPECTION PROCEDURE
When C0200, C0205, C0210, and/or C0215 is output together with
C1235, C1236, C1238, and/or C1239, inspect and repair the trouble
areas indicated by C0200, C0205,
C0210, and/or C0215 first (See
C0200, C0205 for front, or C0210, C0215 for rear).
Detail
- Connect the oscilloscope to each speed sensor terminal of the skid control ECU.
- Check that a waveform is output by each sensor circuit when the tires are rotated.
OK:
The same waveform is output from all the 4 wheels and there is no noise or waveform.
- Check that the waveform does not change while jiggling a connector or a wire harness.
OK:
The waveform does not change.
- As the vehicle speed (wheel revolution speed) increases, a cycle of the waveform narrows and the output voltage becomes greater.
- When noise is identified in the waveform on the oscilloscope, the erratic signals are generated due to speed sensor rotor's scratches, looseness or foreign matter attached to it.
Go to step 3
[2] RECONFIRM DTC
- Turn the ignition switch off.
- Clear the DTC (See Pub. No. S1-YXZE05A, page 05-108).
- Start the engine.
- Drive the vehicle at the speed of 20 km/h (12 mph) or more for at least 30 seconds.
- Check if the same DTC is recorded (See Pub. No. S1- YXZE05A, page 05-108).
Result:
Result Proceed to DTCs (C1235, C1236, C1238 and/or C1239) are not output A DTCs (C1235, C1236, C1238 and/or C1239) are output B
A
CHECK FOR INTERMITTENT PROBLEMS
(SYMPTOM SIMULATION) (See DIAGNOSIS SYSTEM)B
REPLACE SKID CONTROL ECU
- Turn the ignition switch off.
- Disconnect each speed sensor connector.
- Measure the resistance according to the value (s) in the table below.
Standard resistance:
for RH
Tester Connection Condition Specified Condition 1 (FR+) - 2 (FR-) Always 0.9 to 1.3 kΩ at 20ºC (68ºF) 1 (FR+) - Body ground Always 10 kΩ or higher 2 (FR-) - Body ground Always 10 kΩ or higher 1 (RR+) - 2 (RR-) Always 1.4 to 1.8 kΩ at 20ºC (68ºF) 1 (RR+) - Body ground Always 10 kΩ or higher 2 (RR-) - Body ground Always 10 kΩ or higher
for LH
Tester Connection Condition Specified Condition 1 (FL+) - 2 (FL-) Always 0.9 to 1.3 kΩ at 20ºC (68ºF) 1 (FL+) - Body ground Always 10 kΩ or higher 2 (FL-) - Body ground Always 10 kΩ or higher 1 (RL+) - 2 (RL-) Always 1.4 to 1.8 kΩ at 20ºC (68ºF) 1 (RL+) - Body ground Always 10 kΩ or higher 2 (RL-) - Body ground Always 10 kΩ or higher
Check the speed sensor signal after replacement (See TEST MODE PROCEDURE).
REPLACE EACH SPEED SENSOR
[4] CHECK HARNESS AND CONNECTOR
(SKID CONTROL ECU - EACH SPEED SENSOR)
- Disconnect the skid control ECU connectors.
- Measure the resistance according to the value (s) in the table below.
Standard resistance:
for RH
Tester Connection Condition Specified Condition S14-26 (FR+) - A3-1 (FR+) Always Below 1Ω S14-26 (FR+) - Body ground Always 10 kΩ or higher S14-25 (FR-) - A3-2 (FR-) Always Below 1Ω S14-25 (FR-) - Body ground Always 10 kΩ or higher S13-16 (RR+) - A16-1 (RR+) Always Below 1Ω S13-16 (RR+) - Body ground Always 10 kΩ or higher S13-15 (RR-) - A16-2 (RR-) Always Below 1Ω S13-15 (RR-) - Body ground Always 10 kΩ or higher
for LH
Tester Connection Condition Specified Condition S14-27 (FL+) - A2-1 (FL+) Always Below 1Ω S14-27 (FL+) - Body ground Always 10 kΩ or higher S14-28 (FL-) - A2-2 (FL-) Always Below 1Ω S14-28 (FL-) - Body ground Always 10 kΩ or higher S13-22 (RL+) - A15-1 (RL+) Always Below 1Ω S13-22 (RL+) - Body ground Always 10 kΩ or higher S13-23 (RL-) - A15-2 (RL-) Always Below 1Ω S13-23 (RL-) - Body ground Always 10 kΩ or higher
REPAIR OR REPLACE HARNESS OR CONNECTOR
[5] RECONFIRM DTC
- Reconnect the skid control ECU connectors and the speed sensor connector.
- Clear the DTC (See Pub. No. S1-YXZE05A, page 05-108).
- Start the engine.
- Drive the vehicle at the speed of 20 km/h (12 mph) or more for at least 30 seconds.
- Check if the same DTC is recorded (See Pub. No. S1- YXZE05A, page 05-108).
Result:
Result Proceed to DTCs (C1235, C1236, C1238 and/or C1239) are not output A DTCs (C1235, C1236, C1238 and/or C1239) are output B
A
[6] CHECK EACH SPEED SENSOR INSTALLATIONB
CHECK FOR INTERMITTENT PROBLEMS
(SYMPTOM SIMULATION) (See DIAGNOSIS SYSTEM)
- Turn the ignition switch off.
- Check the speed sensor installation.
OK:
There is no clearance between the sensor and the front steering knuckle (for front) or rear axle carrier (for rear).
The installation bolt is tightened properly.
Torque: 8.0 N*m (82 kgf*cm, 71 in.*lbf)
INSTALL EACH SPEED SENSOR CORRECTLY
[7] CHECK EACH SPEED SENSOR TIP
- Remove the each speed sensor (See Pub. No. S1- YXZE05A, SPEED SENSOR FRONT LH for front, or SPEED SENSOR REAR LH for rear).
- Check the speed sensor tip.
OK: No scratches or foreign matter on the sensor tip.
Check the speed sensor signal after cleaning or replacement (See TEST MODE PROCEDURE).
CLEAN OR REPLACE EACH SPEED SENSOR
[8] CHECK EACH SPEED SENSOR ROTOR
- Turn the ignition switch off.
- Remove each speed sensor rotor (See Pub. No. S1-YXZE05A, OVERHAUL for front, or chapter AH for rear).
- Check the speed sensor rotor.
OK: No scratches, missing teeth, or foreign matter on the rotors.
Check the speed sensor signal after cleaning or replacement (See TEST MODE PROCEDURE).
CLEAN OR REPLACE EACH SPEED SENSOR ROTOR
[9] RECONFIRM DTC
- Install the speed sensor and the speed sensor rotor.
- Clear the DTC (See Pub. No. S1-YXZE05A, page 05-108).
- Start the engine.
- Drive the vehicle at the speed of 20 km/h (12 mph) or more for at least 30 seconds.
- Check if the same DTC is recorded (See Pub. No. S1- YXZE05A, page 05-108).
Result:
Result Proceed to DTCs (C1235, C1236, C1238 and/or C1239) are not output A DTCs (C1235, C1236, C1238 and/or C1239) are output B
A
CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (See DIAGNOSIS SYSTEM)B
REPLACE SKID CONTROL ECU
- Confirm the DTC C1277 is inactive
- Start the engine and let it idling condition.
- Verify the DTC C1277 is inactive.
- DTC Clear
- Clear the DTC with Hino DX
- Confirm the same DTC is not reoccurred
- C1277 is reoccur: Return to first process
- Other DTC appear: Refer to concerned Trouble shooting
Complete
