C1273

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1273/73, C1274/74, C1466/33, C1467/34: Low Output Signal of Rear Speed Sensor RH (Test Mode DTC)

DESCRIPTION

The speed sensor detects wheel speed and sends the appropriate signals to the skid control ECU. These signals are used for ABS control.

DTCs C1273/73 and C1274/74 can be cleared when the speed sensor sends a wheel speed signal or when Test Mode ends. DTCs C1273/73 and C1274/74 are output only in Test Mode.

HINT
- DTCs C1466/33 and C1273/73 are for the rear speed sensor RH.
- DTCs C1467/34 and C1274/74 are for the rear speed sensor LH.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
When replacing the brake booster with master cylinder (skid control ECU), perform initialization and calibration of the linear solenoid valve Initialization.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

(a) Using the Techstream, check for any momentary interruptions in the wire harness and connector corresponding to a DTC Check for Intermittent Problems.

ABS/VSC/TRAC

OK:

There are no momentary interruptions.

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

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)

(a) Select the Data List on the Techstream Data List / Active Test.

ABS/VSC/TRAC

(b) Check that 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 On-Vehicle Inspection.

OK:

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

NG -- CHECK REAR SPEED SENSOR INSTALLATION
OK -- Continue to next step.

3. PERFORM TEST MODE INSPECTION (SIGNAL CHECK)

(a) Turn the power 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 -- Continue to next step.

4. RECONFIRM DTC

(a) Turn the power switch off.

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

(c) Turn the power switch on (READY).

(d) Perform a road test.

(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 REAR SPEED SENSOR AND REAR SPEED SENSOR ROTOR

A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting

5. CHECK REAR SPEED SENSOR INSTALLATION

(a) Turn the power switch off.

(b) Check the speed sensor installation.

OK:

There is no clearance between the sensor and rear axle carrier.

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

6. 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 rear speed sensor connector and the skid control sensor wire.

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

Standard Resistance:

for RH
for LH

Text in Illustration

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

NG -- REPLACE SKID CONTROL SENSOR WIRE Removal
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - SKID CONTROL SENSOR WIRE)

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

(b) Disconnect the skid control ECU connector.

(c) 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.

8. INSPECT SKID CONTROL ECU (SENSOR OUTPUT)

(a) Reconnect the skid control ECU connector.

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

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

Standard Voltage:

for RH
for LH

Text in Illustration

NG -- REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Removal
OK -- Continue to next step.

9. RECONFIRM DTC

(a) Turn the power switch off.

(b) Reconnect the rear speed sensor connector and the skid control sensor wire.

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

(d) Turn the power switch on (READY).

(e) Perform a road test.

(f) 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 -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting
A -- Continue to next step.

10. REPLACE REAR SPEED SENSOR AND REAR SPEED SENSOR ROTOR

(a) Turn the power 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.

11. RECONFIRM DTC

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

(b) Turn the power switch on (READY).

(c) Perform a road test.

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

Result: