Lexus NX: Low Output Signal of Rear Speed Sensor RH (C1273,C1274,C1466,C1467)

DESCRIPTION

Each speed sensor detects the wheel speed and sends the signals to the skid control ECU (brake booster with master cylinder assembly). These signals are used for ABS control.

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

DTC No.	Detection Item	INF Code	DTC Detection Condition	Trouble Area	Note
C1273	Low Output Signal of Rear Speed Sensor RH	-	Detected only during Test Mode.	Rear speed sensor RH Sensor installation Rear speed sensor rotor RH (Rear axle hub and bearing assembly RH)	-
C1274	Low Output Signal of Rear Speed Sensor LH	-	Detected only during Test Mode.	Rear speed sensor LH Sensor installation Rear speed sensor rotor LH (Rear axle hub and bearing assembly LH)	-
C1466	Rear Speed Sensor RH Circuit	521 522 523 524 526 527 528	INF Code: 521 At a vehicle speed of 10 km/h (6 mph) or more, speed sensor output from one or two wheels is lower than that from other wheels for 15 seconds or more. INF Code: 522 A malfunction occurs in 2 or more wheels. INF Code: 523 An open is detected in the speed sensor signal circuit for 0.05 seconds or more. INF Code: 524 Instantaneous interruption of sensor signal from the malfunctioning wheel occurs 255 times or more. INF Code: 526 When VM1 voltage is 8.6 V or more, sensor supply voltage drops for 0.5 seconds or more. INF Code: 527 At a vehicle speed of 10 km/h (6 mph) or more, speed sensor output from one wheel is 0 km/h (0 mph) for 1 second or more. INF Code: 528 When VM1 voltage is 8.6 V or more, sensor supply voltage drops for 60 seconds or more.	INF Code: 521, 522, 524, 527 Open or short in speed sensor Improperly installed speed sensor, or abnormal clearance between sensor and rotor Open or short in wire harness Improperly connected connector, deformation or corrosion of terminals Rear speed sensor RH Skid control ECU (Brake booster with master cylinder assembly) INF Code: 523 Open or short in speed sensor Open or short in wire harness Improperly connected connector, deformation or corrosion of terminals Rear speed sensor RH Skid control ECU (Brake booster with master cylinder assembly) INF Code: 526, 528 Open or short in wire harness Skid control ECU (Brake booster with master cylinder assembly)	-
C1467	Rear Speed Sensor LH Circuit	531 532 533 534 536 537 538	INF Code: 531 At a vehicle speed of 10 km/h (6 mph) or more, speed sensor output from one or two wheels is lower than that from other wheels for 15 seconds or more. INF Code: 532 A malfunction occurs in 2 or more wheels. INF Code: 533 An open is detected in the speed sensor signal circuit for 0.05 seconds or more. INF Code: 534 Instantaneous interruption of sensor signal from the malfunctioning wheel occurs 255 times or more. INF Code: 536 When VM1 voltage is 8.6 V or more, sensor supply voltage drops for 0.5 seconds or more. INF Code: 537 At a vehicle speed of 10 km/h (6 mph) or more, speed sensor output from one wheel is 0 km/h (0 mph) for 1 second or more. INF Code: 538 When VM1 voltage is 8.6 V or more, sensor supply voltage drops for 60 seconds or more.	INF Code: 531, 532, 534, 537 Open or short in speed sensor Improperly installed speed sensor, or abnormal clearance between sensor and rotor Open or short in wire harness Improperly connected connector, deformation or corrosion of terminals Rear speed sensor LH Skid control ECU (Brake booster with master cylinder assembly) INF Code: 533 Open or short in speed sensor Open or short in wire harness Improperly connected connector, deformation or corrosion of terminals Rear speed sensor LH Skid control ECU (Brake booster with master cylinder assembly) INF Code: 536, 538 Open or short in wire harness Skid control ECU (Brake booster with master cylinder assembly)	-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

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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.

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Chassis > ABS/VSC/TRAC > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
RR Speed Open	Rear speed sensor RH open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
RL Speed Open	Rear speed sensor LH open detection	Error or Normal	Normal: Normal	Error: Momentary interruption

Chassis > ABS/VSC/TRAC > Data List

Tester Display
RR Speed Open
RL Speed Open

OK:

Normal (There are no momentary interruptions.)

HINT:

Perform the above inspection before removing the sensor and connector.

NG

GO TO STEP 5

OK

2.	READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)

(a) Select the Data List on the Techstream.

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Chassis > ABS/VSC/TRAC > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
RR Wheel Speed	Rear speed sensor RH	Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)	Vehicle stopped: 0 km/h (0 mph)	When driving at constant speed: No large fluctuations
RL Wheel Speed	Rear speed sensor LH	Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)	Vehicle stopped: 0 km/h (0 mph)	When driving at constant speed: No large fluctuations

Chassis > ABS/VSC/TRAC > Data List

Tester Display
RR Wheel Speed
RL Wheel Speed

(b) 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.

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OK:

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

NG

GO TO STEP 5

OK

3.	PERFORM TEST MODE INSPECTION (SIGNAL CHECK)

(a) Turn the power switch off.

(b) Perform the sensor check in Test Mode Procedure.

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Chassis > ABS/VSC/TRAC > Utility

Tester Display
Signal Check

OK:

All Test Mode DTCs are cleared.

NG

GO TO STEP 5

OK

4.	RECONFIRM DTC

(a) Turn the power switch off.

(b) Clear the DTCs.

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Chassis > ABS/VSC/TRAC > Clear DTCs

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

(d) Perform a road test.

(e) Check if the same DTC is output.

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Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1466 and C1467 are not output.	A
DTCs C1466 and/or C1467 are output.	B

HINT:

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

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A

USE SIMULATION METHOD TO CHECK

B

GO TO STEP 10

5.	CHECK REAR SPEED SENSOR INSTALLATION

(a) Turn the power switch off.

*a No clearance *b OK *c NG

(b) Check the speed sensor installation.

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OK:

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

The installation bolt is tightened properly.

NG

INSTALL REAR SPEED SENSOR CORRECTLY

OK

6.	CHECK REAR SPEED SENSOR TIP

(a) Remove the rear speed sensor.

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(b) Check the rear speed sensor tip.

OK:

The sensor tip is free of scratches, oil, and foreign matter.

NG

CLEAN OR REPLACE REAR SPEED SENSOR

OK

7.	CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - REAR SPEED SENSOR)

(a) Install the rear speed sensor.

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

(c) Disconnect the A57 skid control ECU (brake booster with master cylinder assembly) connector.

(d) Disconnect the P14 or Q8 rear speed sensor connector.

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

Standard Resistance:

for RH

Tester Connection	Condition	Specified Condition
A57-22 (RR+) - P14-1 (RR+)	Always	Below 1 Ω
A57-22 (RR+) or P14-1 (RR+) - Body ground	Always	10 kΩ or higher
A57-9 (RR-) - P14-2 (RR-)	Always	Below 1 Ω
A57-9 (RR-) or P14-2 (RR-) - Body ground	Always	10 kΩ or higher

for LH

Tester Connection	Condition	Specified Condition
A57-20 (RL+) - Q8-1 (RL+)	Always	Below 1 Ω
A57-20 (RL+) or Q8-1 (RL+) - Body ground	Always	10 kΩ or higher
A57-7 (RL-) - Q8-2 (RL-)	Always	Below 1 Ω
A57-7 (RL-) or Q8-2 (RL-) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

8.	INSPECT BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SENSOR OUTPUT)

(a) Reconnect the A57 skid control ECU (brake booster with master cylinder assembly) connector.

*A for RH *B for LH *a Front view of wire harness connector (to Rear Speed Sensor)

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

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

Standard Voltage:

for RH

Tester Connection	Switch Condition	Specified Condition
P14-1 (RR+) - Body ground	Power switch on (IG)	5.7 to 14 V

for LH

Tester Connection	Switch Condition	Specified Condition
Q8-1 (RL+) - Body ground	Power switch on (IG)	5.7 to 14 V

NG

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

OK

9.	RECONFIRM DTC

(a) Turn the power switch off.

(b) Reconnect the P14 or Q8 rear speed sensor connector.

(c) Clear the DTCs.

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Chassis > ABS/VSC/TRAC > Clear DTCs

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

(e) Perform a road test.

(f) Check if the same DTC is output.

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Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1466 and/or C1467 are output.	A
DTCs C1466 and C1467 are not output.	B

HINT:

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

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B

USE SIMULATION METHOD TO CHECK

A

10.	REPLACE REAR SPEED SENSOR

(a) Turn the power switch off.

(b) Replace the rear speed sensor.

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NOTICE:

Check the speed sensor signal after replacement.

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NEXT

11.	RECONFIRM DTC

(a) Clear the DTCs.

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Chassis > ABS/VSC/TRAC > Clear DTCs

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

(c) Perform a road test.

(d) Check if the same DTC is output.

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Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1466 and/or C1467 are output.	A
DTCs C1466 and C1467 are not output.	B

HINT:

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

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B

END

A

12.	REPLACE REAR AXLE HUB AND BEARING ASSEMBLY

(a) Turn the power switch off.

(b) Replace the rear speed sensor rotor (rear axle hub and bearing assembly).

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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 the rear axle hub and bearing assembly.

NOTICE:

Check the speed sensor signal after replacement.

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NEXT

13.	RECONFIRM DTC

(a) Clear the DTCs.

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Chassis > ABS/VSC/TRAC > Clear DTCs

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

(c) Perform a road test.

(d) Check if the same DTC is output.

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Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1466 and/or C1467 are output.	A
DTCs C1466 and C1467 are not output.	B

HINT:

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

Click here

A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

END

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