Vehicle Stability Control
BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1273,C1274,C1277,C1278: Low Output Signal of Rear Speed Sensor RH (Test Mode DTC)
C1278 - Abnormal Change in Output Signal of Rear Speed Sensor LH (Test Mode DTC)
DESCRIPTION
DTCs C1273 to C1278 will be cleared when the speed sensor sends a vehicle speed signal or when Test Mode ends. DTCs from C1273 to C1278 are output only in Test Mode.
HINT
* DTCs C1273 and C1277 are for the rear speed sensor RH.
* DTCs C1274 and C1278 are for the rear speed sensor LH.
WIRING DIAGRAM
Refer to DTCs C1403 and C1404 C1403.
INSPECTION PROCEDURE
NOTICE:
When replacing the brake actuator assembly, perform zero point calibration Calibration.
PROCEDURE
1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)
(a) Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to the DTC Check for Intermittent Problems.
ABS/VSC/TRAC
ABS/VSC/TRAC:
Result:
HINT
Perform the above inspection before removing the sensor and connector.
C -- CHECK REAR SPEED SENSOR INSTALLATION
B -- READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)
A -- Continue to next step.
2. REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU - REAR SPEED SENSOR)
(a) Turn the ignition switch off.
(b) Repair or replace the harness or connector.
(c) Check for any momentary interruption between the skid control ECU and the rear speed sensor Check for Intermittent Problems.
(d) Check that there are no momentary interruptions.
NEXT -- Continue to next step.
3. PERFORM TEST MODE (SIGNAL CHECK)
(a) Turn the ignition switch off.
(b) Perform the sensor check in the Test Mode procedure Test Mode Procedure.
OK:
All Test Mode DTCs are cleared.
NG -- READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)
OK -- END
4. READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)
(a) Turn the ignition switch off.
(b) Connect the Techstream to the DLC3.
(c) Start the engine.
(d) Select the Data List on the Techstream Data List / Active Test.
ABS/VSC/TRAC
ABS/VSC/TRAC:
(e) Check that there is no difference between the speed value output from the speed sensor displayed on the Techstream and the speed value displayed on the speedometer when driving the vehicle.
HINT
Factors that affect the indicated vehicle speed include tire size, tire inflation, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart On-Vehicle inspection.
OK:
The speed value output from the speed sensor displayed on the Techstream is the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).
NG -- CHECK REAR SPEED SENSOR INSTALLATION
OK -- Continue to next step.
5. PERFORM TEST MODE (SIGNAL CHECK)
(a) Turn the ignition switch off.
(b) Perform the sensor check in the Test Mode procedure Test Mode Procedure.
OK:
All Test Mode DTCs are cleared.
NG -- CHECK REAR SPEED SENSOR INSTALLATION
OK -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) Diagnosis System
6. CHECK REAR SPEED SENSOR INSTALLATION
(a) Turn the ignition switch off.
(b) Check the speed sensor installation.
OK:
There is no clearance between the sensor and the rear axle carrier.
NG -- INSTALL REAR SPEED SENSOR CORRECTLY Installation
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE)
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(b) Disconnect the skid control sensor wire.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
for RH
for LH
NOTICE:
Check the speed sensor signal after replacement Test Mode Procedure.
NG -- REPLACE SKID CONTROL SENSOR WIRE
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - REAR SPEED SENSOR)
(a) Reconnect the skid control sensor wire.
(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(c) Disconnect the skid control ECU connector and the rear speed sensor connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
for RH
for LH
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. INSPECT SKID CONTROL ECU (SENSOR INPUT)
(a) Reconnect the skid control ECU connector.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
for RH
for LH
NG -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
OK -- Continue to next step.
10. PERFORM TEST MODE (SIGNAL CHECK)
(a) Turn the ignition switch off.
(b) Perform the sensor check in the Test Mode procedure Test Mode Procedure.
OK:
All Test Mode DTCs are cleared.
NG -- REPLACE REAR SPEED SENSOR AND REAR SPEED SENSOR ROTOR
OK -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) Diagnosis System
11. REPLACE REAR SPEED SENSOR AND REAR SPEED SENSOR ROTOR
(a) Turn the ignition switch off.
(b) Replace the rear speed sensor and the rear axle hub and bearing assembly (rear speed sensor rotor) Removal.
HINT
The rear speed sensor rotor is incorporated into the rear axle hub and bearing assembly.
If the rear speed sensor rotor needs to be replaced, replace it together with the rear axle hub and bearing assembly with rear speed sensor.
NOTICE:
Check the speed sensor signal after replacement Test Mode Procedure.
NEXT -- Continue to next step.
12. PERFORM TEST MODE (SIGNAL CHECK)
(a) Perform the sensor check in the Test Mode procedure Test Mode Procedure.
OK:
All Test Mode DTCs are cleared.
NG -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
OK -- END