Toyota Tundra Service Manual: Speed Sensor Rotor Faulty (C1237)

DESCRIPTION

The skid control ECU (brake actuator assembly) measures the speed of each wheel by receiving signals from each speed sensor.

These signals are used for recognizing that all four wheels are operating properly.

Therefore, signals from all wheels must be equal.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1237

Speed Sensor Rotor Faulty

Any of the following is detected:

  • Discrepancy among four wheel speed sensor output.
  • Abnormal pulse signals from 3 or more sensors.
  • Tire and wheel size
  • Tire deformation
  • Speed sensor rotor
  • Speed sensor
  • Speed sensor circuit
  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

Refer to DTCs C1330, C1331, C1332, C1333, C1464, C1465, C1466 and C1467.

Click here

CAUTION / NOTICE / HINT

NOTICE:

When replacing the skid control ECU (brake actuator assembly), perform system variant learning and acceleration sensor zero point calibration.

Click here

HINT:

When C1330, C1331, C1332, C1333, C1464, C1465, C1466 and/or C1467 is output together with C1237, inspect and repair the trouble areas indicated by C1330, C1331, C1332, C1333, C1464, C1465, C1466 and/or C1467 first.

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PROCEDURE

1.

CHECK DTC

(a) Check that the DTC is output.

Click here

Result

Proceed to

C1237 and C1330, C1331, C1332, C1333, 1464, C1465, C1466, C1467 are output simultaneously

A

C1237 is output

B

A

GO TO DTCS (C1330, C1331, C1332, C1333, 1464, C1465, C1466 and/or C1467)

B

2.

CHECK TIRES

(a) Check the size and condition of all four tires.

Click here

HINT:

The DTC is output when tire deformation or a difference in tire size is detected.

OK:

The diameter and tire pressure of all four tires are the same.

NG

REPLACE TIRES SO THAT ALL FOUR TIRES ARE THE SAME SIZE

OK

3.

READ VALUE USING TECHSTREAM (SPEED SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.

ABS/VSC/TRAC

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

FR Wheel Speed

Front wheel speed sensor RH reading

Min.: 0 km/h (0 mph), Max.: 326 km/h (203 mph)

Vehicle stopped: 0 km/h (0 mph)

When driving at constant speed: No large fluctuations

FL Wheel Speed

Front wheel speed sensor LH reading

Min.: 0 km/h (0 mph), Max.: 326 km/h (203 mph)

Vehicle stopped: 0 km/h (0 mph)

When driving at constant speed: No large fluctuations

RR Wheel Speed

Rear wheel speed sensor RH reading

Min.: 0 km/h (0 mph), Max.: 326 km/h (203 mph)

Vehicle stopped: 0 km/h (0 mph)

When driving at constant speed: No large fluctuations

RL Wheel Speed

Rear wheel speed sensor LH reading

Min.: 0 km/h (0 mph), Max.: 326 km/h (203 mph)

Vehicle stopped: 0 km/h (0 mph)

When driving at constant speed: No large fluctuations

(d) Check the speed sensor output value.

OK:

The output value changes in accordance with the vehicle speed.

Result

Proceed to

OK

A

NG (The output value for 1 front speed sensor does not change in accordance with the vehicle speed)

B

NG (The output value for 1 rear speed sensor does not change in accordance with the vehicle speed)

C

NG (The output value of 2 or more sensors does not change in accordance with the vehicle speed)

D

B

GO TO STEP 5

C

GO TO STEP 14

D

REPLACE BRAKE ACTUATOR ASSEMBLY

A

4.

PERFORM TEST MODE INSPECTION (SIGNAL CHECK)

(a) Turn the ignition switch off.

(b) Enter the following menus: Chassis / ABS/VSC/TRAC / Utility / Signal Check.

Click here

(c) Perform the sensor check using Test Mode (Signal Check) Procedure.

Click here

OK:

All Test Mode (Signal Check) inspection items change from incomplete to complete.

Result

Proceed to

OK

A

NG (The Test Mode (Signal Check) inspection item for 1 front speed sensor does not change from incomplete to complete)

B

NG (The Test Mode (Signal Check) inspection item for 1 rear speed sensor does not change from incomplete to complete)

C

NG (The Test Mode (Signal Check) inspection item for 2 or more sensors does not change from incomplete to complete)

D

A

USE SIMULATION METHOD TO CHECK

B

GO TO STEP 5

C

GO TO STEP 14

D

REPLACE BRAKE ACTUATOR ASSEMBLY

5.

CHECK FRONT SPEED SENSOR INSTALLATION

(a) Turn the ignition switch off.

*a

Normal

*b

Abnormal

*c

Clearance

(b) Check the speed sensor installation.

Click here

OK:

There is no clearance between the sensor and the front steering knuckle.

The installation bolt is tightened properly.

NG

REINSTALL OR REPLACE FRONT SPEED SENSOR

OK

6.

CHECK FRONT SPEED SENSOR (CHECK FOR FOREIGN MATTER)

(a) Remove the front speed sensor.

Click here

(b) Check the front speed sensor tip.

OK:

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

NOTICE:

  • If there is oil or foreign matter on the speed sensor, clean the speed sensor.
  • If the speed sensor is damaged, replace the speed sensor with a new one.
  • Check the speed sensor signal after cleaning or replacement.

    Click here

NG

CLEAN OR REPLACE FRONT SPEED SENSOR

OK

7.

INSPECT BRAKE ACTUATOR ASSEMBLY (POWER SOURCE CIRCUIT)

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

OK:

The connector is securely connected.

*A

for RH

*B

for LH

*a

Front view of wire harness connector

(to Front Speed Sensor)

(b) Disconnect the b1 or b2 front speed sensor connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

(d) Turn the ignition switch to ON.

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

Standard Voltage:

for RH

Tester Connection

Condition

Specified Condition

b1-2 - Body ground

Ignition switch ON

5.5 to 14 V

for LH

Tester Connection

Condition

Specified Condition

b2-2 - Body ground

Ignition switch ON

5.5 to 14 V

NG

GO TO STEP 12

OK

8.

INSPECT BRAKE ACTUATOR ASSEMBLY (GROUND CIRCUIT)

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

Standard Voltage:

for RH

Tester Connection

Condition

Specified Condition

b1-2 - b1-1

Ignition switch ON

5.5 to 14 V

for LH

Tester Connection

Condition

Specified Condition

b2-2 - b2-1

Ignition switch ON

5.5 to 14 V

*A

for RH

*B

for LH

*a

Front view of wire harness connector

(to Front Speed Sensor)

NG

GO TO STEP 10

OK

9.

CHECK FRONT SPEED SENSOR ROTOR (CHECK FOR FOREIGN MATTER)

(a) Remove the front speed sensor rotor (front axle with ABS rotor bearing assembly).

Click here

(b) Check the speed sensor rotor.

OK:

The rotor is free of scratches, oil, and foreign matter.

NOTICE:

Check the speed sensor signal after cleaning or replacement.

Click here

HINT:

  • The front speed sensor rotor is incorporated into the front axle with ABS rotor bearing assembly.
  • If the front speed sensor rotor needs to be replaced, replace it together with the front axle with ABS rotor bearing assembly.

Result

Proceed to

OK

A

NG (The speed sensor rotor is damaged)

B

NG (There is oil or foreign matter on the speed sensor rotor)

C

A

REPLACE FRONT SPEED SENSOR

B

REPLACE FRONT AXLE WITH ABS ROTOR BEARING ASSEMBLY

C

CLEAN FRONT SPEED SENSOR ROTOR

10.

INSPECT SKID CONTROL SENSOR WIRE

(a) Turn the ignition switch off.

*A

for RH

*a

Front view of skid control sensor wire

*b

Front view of wire harness connector

(to Sensor Side Connector)

*c

Front view of wire harness connector

(to Vehicle Side Connector)

*A

for LH

*a

Front view of skid control sensor wire

*b

Front view of wire harness connector

(to Sensor Side Connector)

*c

Front view of wire harness connector

(to Vehicle Side Connector)

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

OK:

The connector is securely connected.

(c) Disconnect the Ab2 or Ab1 skid control sensor wire.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

for RH

Tester Connection

Condition

Specified Condition

b1-1 - Ab2-1

Always

Below 1 Ω

b1-1 - Ab2-2

Always

10 kΩ or higher

b1-1 or Ab2-1 - Body ground

Always

10 kΩ or higher

for LH

Tester Connection

Condition

Specified Condition

b2-1 - Ab1-1

Always

Below 1 Ω

b2-1 - Ab1-2

Always

10 kΩ or higher

b2-1 or Ab1-1 - Body ground

Always

10 kΩ or higher

NOTICE:

Check the speed sensor signal after replacement.

Click here

NG

REPLACE SKID CONTROL SENSOR WIRE

OK

11.

CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - SKID CONTROL SENSOR WIRE)

(a) Turn the ignition switch off.

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

OK:

The connector is securely connected.

(c) Disconnect the A57 skid control ECU (brake actuator assembly) connector.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

for RH:

Tester Connection

Condition

Specified Condition

A57-26 (FR-) - Ab2-1

Always

Below 1 Ω

A57-26 (FR-) or Ab2-1 - Body ground

Always

10 kΩ or higher

for LH:

Tester Connection

Condition

Specified Condition

A57-37 (FL-) - Ab1-1

Always

Below 1 Ω

A57-37 (FL-) or Ab1-1 - Body ground

Always

10 kΩ or higher

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

12.

INSPECT SKID CONTROL SENSOR WIRE

(a) Turn the ignition switch off.

*A

for RH

*a

Front view of skid control sensor wire

*b

Front view of wire harness connector

(to Sensor Side Connector)

*c

Front view of wire harness connector

(to Vehicle Side Connector)

*A

for LH

*a

Front view of skid control sensor wire

*b

Front view of wire harness connector

(to Sensor Side Connector)

*c

Front view of wire harness connector

(to Vehicle Side Connector)

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

OK:

The connector is securely connected.

(c) Disconnect the Ab2 or Ab1 skid control sensor wire.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

for RH

Tester Connection

Condition

Specified Condition

b1-2 - Ab2-2

Always

Below 1 Ω

b1-2 - Ab2-1

Always

10 kΩ or higher

b1-2 or Ab2-2 - Body ground

Always

10 kΩ or higher

for LH

Tester Connection

Condition

Specified Condition

b2-2 - Ab1-2

Always

Below 1 Ω

b2-2 - Ab1-1

Always

10 kΩ or higher

b2-2 or Ab1-2 - Body ground

Always

10 kΩ or higher

NOTICE:

Check the speed sensor signal after replacement.

Click here

NG

REPLACE SKID CONTROL SENSOR WIRE

OK

13.

CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - SKID CONTROL SENSOR WIRE)

(a) Turn the ignition switch off.

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

OK:

The connector is securely connected.

(c) Disconnect the A57 skid control ECU (brake actuator assembly) connector.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

for RH:

Tester Connection

Condition

Specified Condition

A57-27 (FR+) - Ab2-2

Always

Below 1 Ω

A57-27 (FR+) or Ab2-2 - Body ground

Always

10 kΩ or higher

for LH:

Tester Connection

Condition

Specified Condition

A57-36 (FL+) - Ab1-2

Always

Below 1 Ω

A57-36 (FL+) or Ab1-2 - Body ground

Always

10 kΩ or higher

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.

CHECK REAR SPEED SENSOR INSTALLATION

(a) Turn the ignition switch off.

*a

Normal

*b

Abnormal

*c

Clearance

(b) Check the speed sensor installation.

Click here

OK:

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

The installation bolt is tightened properly.

NG

REINSTALL OR REPLACE REAR SPEED SENSOR

OK

15.

CHECK REAR SPEED SENSOR (CHECK FOR FOREIGN MATTER)

(a) Remove the rear speed sensor.

Click here

(b) Check the rear speed sensor tip.

OK:

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

NOTICE:

  • If there is oil or foreign matter on the speed sensor, clean the speed sensor.
  • If the speed sensor is damaged, replace the speed sensor with a new one.
  • Check the speed sensor signal after cleaning or replacement.

    Click here

NG

CLEAN OR REPLACE FRONT SPEED SENSOR

OK

16.

INSPECT BRAKE ACTUATOR ASSEMBLY (POWER SOURCE CIRCUIT)

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

OK:

The connector is securely connected.

*A

for RH

*B

for LH

*a

Front view of wire harness connector

(to Rear Speed Sensor)

(b) Disconnect the b3 or b4 rear speed sensor connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

(d) Turn the ignition switch to ON.

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

Standard Voltage:

for RH

Tester Connection

Condition

Specified Condition

b3-2 - Body ground

Ignition switch ON

5.5 to 14 V

for LH

Tester Connection

Condition

Specified Condition

b4-2 - Body ground

Ignition switch ON

5.5 to 14 V

NG

GO TO STEP 21

OK

17.

INSPECT BRAKE ACTUATOR ASSEMBLY (GROUND CIRCUIT)

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

Standard Voltage:

for RH

Tester Connection

Condition

Specified Condition

b3-2 - b3-1

Ignition switch ON

5.5 to 14 V

for LH

Tester Connection

Condition

Specified Condition

b4-2 - b4-1

Ignition switch ON

5.5 to 14 V

*A

for RH

*B

for LH

*a

Front view of wire harness connector

(to Rear Speed Sensor)

NG

GO TO STEP 19

OK

18.

CHECK REAR SPEED SENSOR ROTOR (CHECK FOR FOREIGN MATTER)

(a) Remove the rear speed sensor rotor (rear axle hub and bearing assembly).

Click here

Click here

(b) Check the speed sensor rotor.

OK:

The rotor is free of scratches, oil, and foreign matter.

NOTICE:

Check the speed sensor signal after cleaning or replacement.

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 it together with the rear axle hub and bearing assembly.

Result

Proceed to

OK

A

NG (The speed sensor rotor is damaged)

B

NG (There is oil or foreign matter on the speed sensor rotor)

C

A

REPLACE REAR SPEED SENSOR

B

REPLACE REAR AXLE HUB AND BEARING ASSEMBLY

C

CLEAN REAR SPEED SENSOR ROTOR

19.

INSPECT SKID CONTROL SENSOR WIRE

(a) Turn the ignition switch off.

*A

for RH

*a

Front view of skid control sensor wire

*b

Front view of wire harness connector

(to Sensor Side Connector)

*c

Front view of wire harness connector

(to Vehicle Side Connector)

*A

for LH

*a

Front view of skid control sensor wire

*b

Front view of wire harness connector

(to Sensor Side Connector)

*c

Front view of wire harness connector

(to Vehicle Side Connector)

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

OK:

The connector is securely connected.

(c) Disconnect the Rb1 skid control sensor wire.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

for RH

Tester Connection

Condition

Specified Condition

b3-1 - Rb1-3

Always

Below 1 Ω

b3-1 - Rb1-4

Always

10 kΩ or higher

b3-1 - Rb1-2

Always

10 kΩ or higher

b3-1 - Rb1-1

Always

10 kΩ or higher

b3-1 or Rb1-1 - Body ground

Always

10 kΩ or higher

for LH

Tester Connection

Condition

Specified Condition

b4-1 - Rb1-1

Always

Below 1 Ω

b4-1 - Rb1-2

Always

10 kΩ or higher

b4-1 - Rb1-3

Always

10 kΩ or higher

b4-1 - Rb1-4

Always

10 kΩ or higher

b4-1 or Rb1-1 - Body ground

Always

10 kΩ or higher

NOTICE:

Check the speed sensor signal after replacement.

Click here

NG

REPLACE SKID CONTROL SENSOR WIRE

OK

20.

CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - SKID CONTROL SENSOR WIRE)

(a) Turn the ignition switch off.

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

OK:

The connector is securely connected.

(c) Disconnect the A57 skid control ECU (brake actuator assembly) connector.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

for RH:

Tester Connection

Condition

Specified Condition

A57-33 (RR-) - Rb1-3

Always

Below 1 Ω

A57-33 (RR-) or Rb1-3 - Body ground

Always

10 kΩ or higher

for LH:

Tester Connection

Condition

Specified Condition

A57-30 (RL-) - Rb1-1

Always

Below 1 Ω

A57-30 (RL-) or Rb1-1 - Body ground

Always

10 kΩ or higher

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

21.

INSPECT SKID CONTROL SENSOR WIRE

(a) Turn the ignition switch off.

*A

for RH

*a

Front view of skid control sensor wire

*b

Front view of wire harness connector

(to Sensor Side Connector)

*c

Front view of wire harness connector

(to Vehicle Side Connector)

*A

for LH

*a

Front view of skid control sensor wire

*b

Front view of wire harness connector

(to Sensor Side Connector)

*c

Front view of wire harness connector

(to Vehicle Side Connector)

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

OK:

The connector is securely connected.

(c) Disconnect the Rb1 skid control sensor wire.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

for RH

Tester Connection

Condition

Specified Condition

b3-2 - Rb1-4

Always

Below 1 Ω

b3-2 - Rb1-3

Always

10 kΩ or higher

b3-2 - Rb1-2

Always

10 kΩ or higher

b3-2 - Rb1-2

Always

10 kΩ or higher

b3-2 or Rb1-2 - Body ground

Always

10 kΩ or higher

for LH

Tester Connection

Condition

Specified Condition

b4-2 - Rb1-2

Always

Below 1 Ω

b4-2 - Rb1-1

Always

10 kΩ or higher

b4-2 - Rb1-3

Always

10 kΩ or higher

b4-2 - Rb1-4

Always

10 kΩ or higher

b4-2 or Rb1-2 - Body ground

Always

10 kΩ or higher

NOTICE:

Check the speed sensor signal after replacement.

Click here

NG

REPLACE SKID CONTROL SENSOR WIRE

OK

22.

CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - SKID CONTROL SENSOR WIRE)

(a) Turn the ignition switch off.

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

OK:

The connector is securely connected.

(c) Disconnect the A57 skid control ECU (brake actuator assembly) connector.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

for RH:

Tester Connection

Condition

Specified Condition

A57-34 (RR+) - Rb1-4

Always

Below 1 Ω

A57-34 (RR+) or Rb1-4 - Body ground

Always

10 kΩ or higher

for LH:

Tester Connection

Condition

Specified Condition

A57-29 (RL+) - Rb1-2

Always

Below 1 Ω

A57-29 (RL+) or Rb1-2 - Body ground

Always

10 kΩ or higher

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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