Abnormal Change in Output Signal of Rear Speed Sensor RH (Test Mode DTC) - Vehicle Stability Control System (for BOSCH Made)

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM (for BOSCH Made): C0210/33, C0215/34, C1273/73, C1274/74, C1277/77, C1278/78, C1332/38, C1333/39: Right Rear Wheel Speed Sensor Signal Malfunction

DTC C0210/33 - Right Rear Wheel Speed Sensor Signal Malfunction

DTC C0215/34 - Left Rear Wheel Speed Sensor Signal Malfunction

DTC C1273/73 - Low Output Signal of Rear Speed Sensor RH (Test Mode DTC)

DTC C1274/74 - Low Output Signal of Rear Speed Sensor LH (Test Mode DTC)

DTC C1277/77 - Abnormal Change in Output Signal of Rear Speed Sensor RH (Test Mode DTC)

DTC C1278/78 - Abnormal Change in Output Signal of Rear Speed Sensor LH (Test Mode DTC)

DTC C1332/38 - Right Rear Speed Sensor Circuit

DTC C1333/39 - Left Rear Speed Sensor Circuit

DESCRIPTION

The speed sensors detects wheel speed and transmit the signals to the skid control 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 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.

DTCs from C1273/73 to C1278/78 can be deleted when the speed sensor sends a vehicle speed signal or the test mode ends. DTCs from C1273/73 to C1278/78 are output only in the test mode.

HINT:
DTC No. C0210/33 and C1332/38 are for the rear speed sensor RH.
DTC No. C0215/34 and C1333/39 are for the rear speed sensor LH.

WIRING DIAGRAM

INSPECTION PROCEDURE
HINT: Check the condition of each related circuit connector before troubleshooting Electronic Circuit Inspection Procedure.

PROCEDURE

1. READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)
(a) Connect Techstream to the DLC3.
(b) Start the engine.
(c) Select "Data List" and read the value displayed on Techstream Data List / Active Test.

Data List: ABS / VSC / TRAC

B -- INSPECT SPEED SENSOR INSTALLATION
A -- Continue to next step.
3. INSPECT SPEED SENSOR SIGNAL WAVEFORM

(a) Lift up the vehicle.
(b) Perform the inspection using an oscilloscope.
(1) Disconnect the skid control ECU connector.
(2) Connect the oscilloscope to the rear speed sensor terminals of the skid control ECU.
(3) Check that a waveform is output when the tires are rotated.
OK:
The same waveform is output from all the 4 wheels and there is no noise or interference in the waveform.
HINT:
- As vehicle speed (wheel rotation speed) increases, the width 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 rotor scratches, looseness or foreign matter attached to the speed sensor.

(4) Connect the connector.
NG -- REPAIR OR REPLACE SPEED SENSOR AND SENSOR ROTOR
OK -- Continue to next step.
4. RECONFIRM DTC
(a) Clear the DTCs Vehicle Stability Control System (for BOSCH Made).
(b) Drive the vehicle at a speed of approximately 25 mph (40 km/h) or more for 60 seconds or more.
(c) Check if the same DTCs are recorded Vehicle Stability Control System (for BOSCH Made).
HINT: Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

Result:

C -- END
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.
5. INSPECT SPEED SENSOR INSTALLATION

(a) Check the rear speed sensor installation.
OK:
There is no clearance between the sensor and rear axle carrier.
NOTICE: Check the speed sensor signal after replacement Test Mode Procedure.

NG -- INSTALL REAR SPEED SENSOR CORRECTLY
OK -- Continue to next step.
6. INSPECT REAR SPEED SENSOR

(a) Disconnect the rear speed sensor connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
LH

NOTICE: Check the speed sensor signal after replacement Test Mode Procedure.

NG -- REPLACE REAR SPEED SENSOR
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU TO SKID CONTROL SENSOR WIRE)

(a) Check the harness and connector.
(1) Disconnect the skid control ECU connector and the rear speed sensor connector.
(2) Disconnect the skid control sensor wire.
(3) Measure the resistance according to the value(s) in the table below.
Standard resistance:
LH

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU TO SKID CONTROL SENSOR WIRE)
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE TO REAR SPEED SENSOR)

(a) Check harness and connector (skid control sensor wire).
(1) Measure the resistance according to the value(s) in the table below.
Standard resistance:
LH

(2) Connect the connector.
NG -- REPAIR OR REPLACE SKID CONTROL SENSOR WIRE
OK -- Continue to next step.
9. INSPECT SPEED SENSOR SIGNAL WAVEFORM

(a) Lift up the vehicle.
(b) Perform the inspection using an oscilloscope.
(1) Disconnect the skid control ECU connector.
(2) Connect the oscilloscope to the rear speed sensor terminals of the skid control ECU.
(3) Check that a waveform is output when the tires are rotated.
OK:
The same waveforms is output from rear wheels and there is no noise or interference in the waveform.
HINT:
- As vehicle speed (wheel rotation speed) increases, the width 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 rotor scratches, looseness or foreign matter attached to the speed sensor.

(4) Connect the connector.
NG -- CLEAN OR REPLACE SPEED SENSOR AND SENSOR ROTOR
OK -- Continue to next step.
10. READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)
(a) Connect Techstream to the DLC3.
(b) Start the engine.
(c) Select "Data List" and read the value displayed on Techstream Data List / Active Test.

Data List: ABS / VSC / TRAC

(d) Check that there is no difference between the speed value output from the speed sensor displayed on Techstream and the speed value displayed on the speedometer when driving the vehicle.
OK:
The speed value output from the speed sensor displayed on Techstream is the same as the actual vehicle speed.
HINT:
- It is suspected that the DTCs were output due to a bad connection of the connector terminal.
- If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step Problem Symptoms Table.

NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
OK -- Continue to next step.
11. RECONFIRM DTC
(a) Clear the DTCs Vehicle Stability Control System (for BOSCH Made).
(b) Drive the vehicle at a speed of approximately 25 mph (40 km/h) or more for 60 seconds or more.
(c) Check if the same DTCs are recorded Vehicle Stability Control System (for BOSCH Made).
HINT: Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

Result:

C -- END
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.
12. INSPECT SPEED SENSOR ROTOR
(a) Turn the ignition switch off.
(b) Remove the rear axle.
(c) Check the rotor.
OK:
No scratches, cracks, oil, or foreign matter on the rotors.
NOTICE: Check the speed sensor signal after cleaning or replacement Test Mode Procedure.
(d) Install the rear axle.
NG -- CLEAN OR REPLACE SPEED SENSOR ROTOR
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY