C1408

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1407,C1408: Open or Short in Rear Speed Sensor RH Circuit


DESCRIPTION

The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU. These signals are used for the ABS control system. This speed sensor contains a sensor IC, which consists of 2 MREs (Magnetic Resistance Elements). The speed sensor rotor, which consists of 48 sets of N and S poles arranged in a circle, is integrated with the inner race of the hub bearing.

To detect the rotation direction, the output waves are used to determine the relationship of the pulses that are generated by the 2 MREs. Upon receiving this signal, the sensor IC outputs a forward or backward waveform to the ECU.









HINT
- DTC C1407 is for the rear speed sensor RH.
- DTC C1408 is 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 and store system information Programming and Relearning.

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:

OK:

There are no momentary interruptions.

HINT
Perform the above inspection before removing the sensor and connector.

NG -- CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE)
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)

(a) Turn the engine 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 the speed value output from the speed sensor displayed on the Techstream.

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 Meter / Gauge System.

OK:

The speed value output from the speed sensor displayed on the Techstream is the similar speed as indicated on the speedometer.

NG -- CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE)
OK -- Continue to next step.

3. RECONFIRM DTC

(a) Turn the engine switch off.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Start the engine.

(d) Drive the vehicle at a speed of 40 km/h (25 mph) or more for at least 60 seconds.

(e) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result:





HINT
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.

B -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

A -- CHECK FOR INTERMITTENT PROBLEMS Electronic Circuit Inspection Procedure

4. CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE)

(a) Turn the engine switch off.





(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.

(c) Disconnect the rear speed sensor connector and the skid control sensor wire.

(d) 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.

5. 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.

(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.

6. INSPECT SKID CONTROL ECU (SENSOR INPUT)

(a) Reconnect the skid control ECU connector.





(b) Turn the engine switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

for RH
for LH










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

HINT
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.

NG -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

OK -- REPLACE REAR SPEED SENSOR Removal