Lexus NX: Foreign Object is Attached on Tip of Front Speed Sensor RH (C1235,C1236,C1238,C1239,C1275-C1278)

Lexus NX Service Manual / Brake / Brake Control / Dynamic Control Systems / Electronically Controlled Brake System / Foreign Object is Attached on Tip of Front Speed Sensor RH (C1235,C1236,C1238,C1239,C1275-C1278)

DESCRIPTION

When foreign matter adheres to a speed sensor tip or speed sensor rotor, these DTCs are stored. The presence of foreign matter can be judged when an abnormal waveform is received from a sensor.

These DTCs may also be detected when a malfunction occurs in the connector terminals or wire harness of the speed sensor circuit.

DTCs C1275 to C1278 will be cleared when the speed sensor sends a wheel speed signal or when Test Mode ends. DTCs from C1275 to C1278 are output only in Test Mode.

DTC No.	Detection Item	INF Code	DTC Detection Condition	Trouble Area	Note
C1235	Foreign Object is Attached on Tip of Front Speed Sensor RH	541	Either of the following is detected: At a vehicle speed of 20 km/h (12 mph) or more, noise occurs on the speed sensor signal waveform for 5 seconds or more. At a vehicle speed of 10 km/h (6 mph) or more, noise occurs once per wheel revolution for 15 seconds or more.	Speed sensor rotor malfunction (foreign matter attached) Foreign matter attached to speed sensor Open or short in speed sensor Open or short in wire harness Improperly connected connector, deformation or corrosion of terminals Resistance in speed sensor circuit Skid control ECU (Brake booster with master cylinder assembly)	-
C1236	Foreign Object is Attached on Tip of Front Speed Sensor LH	542	Either of the following is detected: At a vehicle speed of 20 km/h (12 mph) or more, noise occurs on the speed sensor signal waveform for 5 seconds or more. At a vehicle speed of 10 km/h (6 mph) or more, noise occurs once per wheel revolution for 15 seconds or more.	Speed sensor rotor malfunction (foreign matter attached) Foreign matter attached to speed sensor Open or short in speed sensor Open or short in wire harness Improperly connected connector, deformation or corrosion of terminals Resistance in speed sensor circuit Skid control ECU (Brake booster with master cylinder assembly)	-
C1238	Foreign Object is Attached on Tip of Rear Speed Sensor RH	543	Either of the following is detected: At a vehicle speed of 20 km/h (12 mph) or more, noise occurs on the speed sensor signal waveform for 5 seconds or more. At a vehicle speed of 10 km/h (6 mph) or more, noise occurs once per wheel revolution for 15 seconds or more.	Speed sensor rotor malfunction (foreign matter attached) Foreign matter attached to speed sensor Open or short in speed sensor Open or short in wire harness Improperly connected connector, deformation or corrosion of terminals Resistance in speed sensor circuit Skid control ECU (Brake booster with master cylinder assembly)	-
C1239	Foreign Object is Attached on Tip of Rear Speed Sensor LH	544	Either of the following is detected: At a vehicle speed of 20 km/h (12 mph) or more, noise occurs on the speed sensor signal waveform for 5 seconds or more. At a vehicle speed of 10 km/h (6 mph) or more, noise occurs once per wheel revolution for 15 seconds or more.	Speed sensor rotor malfunction (foreign matter attached) Foreign matter attached to speed sensor Open or short in speed sensor Open or short in wire harness Improperly connected connector, deformation or corrosion of terminals Resistance in speed sensor circuit Skid control ECU (Brake booster with master cylinder assembly)	-
C1275	Abnormal Change in Output Signal of Front Speed Sensor RH	-	Detected only during Test Mode.	Front speed sensor RH Front speed sensor rotor RH (Front axle hub sub-assembly RH)	-
C1276	Abnormal Change in Output Signal of Front Speed Sensor LH	-	Detected only during Test Mode.	Front speed sensor LH Front speed sensor rotor LH (Front axle hub sub-assembly LH)	-
C1277	Abnormal Change in Output Signal of Rear Speed Sensor RH	-	Detected only during Test Mode.	Rear speed sensor RH Rear speed sensor rotor RH (Rear axle hub and bearing assembly RH)	-
C1278	Abnormal Change in Output Signal of Rear Speed Sensor LH	-	Detected only during Test Mode.	Rear speed sensor LH Rear speed sensor rotor LH (Rear axle hub and bearing assembly LH)	-

WIRING DIAGRAM

Refer to DTCs C1464, C1465, C1466 and C1467.

for Front: Click here

for Rear: Click here

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.

Click here

PROCEDURE

CHECK DTC

(a) Check that no speed sensor malfunction DTCs are output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

HINT:

When C1464, C1465, C1466, and/or C1467 are output together with C1235, C1236, C1238, and/or C1239, inspect and repair the trouble areas indicated by C1464, C1465, C1466, and/or C1467 first.

Result	Proceed to
DTCs C1235 and/or C1236 are output.	A
DTCs C1238 and C1239 are output.	B
Speed sensor malfunction DTCs (C1464, C1465, C1466 and/or C1467) are output.	C

GO TO STEP 13

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

2.	CHECK FRONT SPEED SENSOR AND SENSOR ROTOR

(a) Remove the front speed sensor and the component with the sensor rotor.

for Speed Sensor: Click here

for Speed Sensor Rotor: Click here

(b) Check the speed sensor tip and speed sensor rotor.

OK:

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

NOTICE:

If no damage to the speed sensor tip is found during this inspection, do not replace the speed sensor.
If there are any ferrous metal filings stuck to the rotor, this will result in a malfunction, so confirm that the rotor is not contaminated with foreign matter before replacing the sensor.
Check the speed sensor signal after cleaning or replacement.
Click here

OK (w/ AVS)

GO TO STEP 10

CLEAN OR REPLACE FRONT SPEED SENSOR OR COMPONENT WITH SENSOR ROTOR

OK (w/o AVS)

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

(a) Install the front speed sensor and the component with the sensor rotor.

for Speed Sensor: Click here

for Speed Sensor Rotor: Click here

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

(d) Disconnect the A12 or A13 front 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
A57-18 (FR+) - A12-6 (FR+)	Always	Below 1 Ω
A57-18 (FR+) or A12-6 (FR+) - Body ground	Always	10 kΩ or higher
A57-5 (FR-) - A12-5 (FR-)	Always	Below 1 Ω
A57-5 (FR-) or A12-5 (FR-) - Body ground	Always	10 kΩ or higher

for LH

Tester Connection	Condition	Specified Condition
A57-31 (FL+) - A13-6 (FL+)	Always	Below 1 Ω
A57-31 (FL+) or A13-6 (FL+) - Body ground	Always	10 kΩ or higher
A57-32 (FL-) - A13-5 (FL-)	Always	Below 1 Ω
A57-32 (FL-) or A13-5 (FL-) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

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

for RH

for LH

Front view of wire harness connector

(to Front Speed Sensor)

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

Standard Voltage:

for RH

Tester Connection	Switch Condition	Specified Condition
A12-6 (FR+) - Body ground	Power switch on (IG)	5.7 to 14 V

for LH

Tester Connection	Switch Condition	Specified Condition
A13-6 (FL+) - Body ground	Power switch on (IG)	5.7 to 14 V

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

5.	RECONFIRM DTC

(a) Turn the power switch off.

(b) w/o AVS

Reconnect the A12 or A13 front speed sensor connector.

Reconnect the A or B front skid control sensor wire connector.

(d) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

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

(f) Drive the vehicle at a speed of 20 km/h (12 mph) or more for at least 15 seconds.

(g) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1235 and/or C1236 are output.	A
DTCs C1235 and C1236 are not output.	B

USE SIMULATION METHOD TO CHECK

6.	REPLACE FRONT SPEED SENSOR

(a) Turn the power switch off.

(b) Replace the front speed sensor.

Click here

NOTICE:

Check the speed sensor signal after replacement.

Click here

7.	RECONFIRM DTC

(a) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

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

(d) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1235 and/or C1236 are output.	A
DTCs C1235 and C1236 are not output.	B

END

8.	REPLACE FRONT AXLE HUB SUB-ASSEMBLY

(a) Turn the power switch off.

(b) Replace the front speed sensor rotor (front axle hub sub-assembly).

Click here

HINT:

The front speed sensor rotor is incorporated into the front axle hub sub-assembly.

If the front speed sensor rotor needs to be replaced, replace the front axle hub sub-assembly.

NOTICE:

Check the speed sensor signal after replacement.

Click here

9.	RECONFIRM DTC

(a) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

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

(d) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1235 and/or C1236 are output.	A
DTCs C1235 and C1236 are not output.	B

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

END

10.	INSPECT FRONT SKID CONTROL SENSOR WIRE

(a) Install the front speed sensor and the component with the sensor rotor.

for Speed Sensor: Click here

for Speed Sensor Rotor: Click here

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

(d) Disconnect the A or B front skid control sensor wire connector.

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

for RH

for LH

Front Skid Control Sensor Wire

Front view of wire harness connector

(to Front Speed Sensor Side Connector)

Front view of wire harness connector

(to Vehicle Side Connector)

Standard Resistance:

for RH

Tester Connection	Condition	Specified Condition
A-1 - A75-6 (FR+)	Always	Below 1 Ω
A-1 or A75-6 (FR+) - Body ground and other terminals	Always	10 kΩ or higher
A-2 - A75-5 (FR-)	Always	Below 1 Ω
A-2 or A75-5 (FR-) - Body ground and other terminals	Always	10 kΩ or higher

for LH

Tester Connection	Condition	Specified Condition
B-1 - A76-6 (FL+)	Always	Below 1 Ω
B-1 or A76-6 (FL+) - Body ground and other terminals	Always	10 kΩ or higher
B-2 - A76-5 (FL-)	Always	Below 1 Ω
B-2 or A76-5 (FL-) - Body ground and other terminals	Always	10 kΩ or higher

REPLACE FRONT SKID CONTROL SENSOR WIRE

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

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

(b) Reconnect the A75 or A76 front skid control sensor wire connector.

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

Standard Resistance:

for RH

Tester Connection	Condition	Specified Condition
A57-18 (FR+) - A-1	Always	Below 1 Ω
A57-18 (FR+) or A-1 - Body ground	Always	10 kΩ or higher
A57-5 (FR-) - A-2	Always	Below 1 Ω
A57-5 (FR-) or A-2 - Body ground	Always	10 kΩ or higher

for LH

Tester Connection	Condition	Specified Condition
A57-31 (FL+) - B-1	Always	Below 1 Ω
A57-31 (FL+) or B-1 - Body ground	Always	10 kΩ or higher
A57-32 (FL-) - B-2	Always	Below 1 Ω
A57-32 (FL-) or B-2 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

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

for RH

for LH

Front view of wire harness connector

(to Front Speed Sensor)

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

Standard Voltage:

for RH

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

for LH

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

GO TO STEP 5

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

13.	CHECK REAR SPEED SENSOR AND SENSOR ROTOR

(a) Remove the rear speed sensor and the component with the sensor rotor.

for Speed Sensor: Click here

for Speed Sensor Rotor: Click here

(b) Check the speed sensor tip and speed sensor rotor.

OK:

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

NOTICE:

If no damage to the speed sensor tip is found during this inspection, do not replace the speed sensor.
If there are any ferrous metal filings stuck to the rotor, this will result in a malfunction, so confirm that the rotor is not contaminated with foreign matter before replacing the sensor.
Check the speed sensor signal after cleaning or replacement.
Click here

CLEAN OR REPLACE REAR SPEED SENSOR OR COMPONENT WITH SENSOR ROTOR

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

(a) Install the rear speed sensor and the component with the sensor rotor.

for Speed Sensor: Click here

for Speed Sensor Rotor: Click here

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

(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

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

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

for RH

for LH

Front view of wire harness connector

(to Rear Speed Sensor)

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

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

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

16.	RECONFIRM DTC

(a) Turn the power switch off.

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

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

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

(e) Drive the vehicle at a speed of 20 km/h (12 mph) or more for at least 15 seconds.

(f) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1238 and/or C1239 are output.	A
DTCs C1238 and C1239 are not output.	B

USE SIMULATION METHOD TO CHECK

17.	REPLACE REAR SPEED SENSOR

(a) Turn the power switch off.

(b) Replace the rear speed sensor.

Click here

NOTICE:

Check the speed sensor signal after replacement.

Click here

18.	RECONFIRM DTC

(a) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

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

(d) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1238 and/or C1239 are output.	A
DTCs C1238 and C1239 are not output.	B

END

19.	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).

Click here

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.

Click here

20.	RECONFIRM DTC

(a) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

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

(d) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTCs C1238 and/or C1239 are output.	A
DTCs C1238 and C1239 are not output.	B

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

END

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