Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM1000000018KEH
Model Year Start: 2018 Model: Sienna Prod Date Range: [11/2017 -           ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1405,C1406; Open or Short in Front Speed Sensor RH Circuit; 2018 - 2020 MY Sienna [11/2017 -        ]

DTC

C1405

Open or Short in Front Speed Sensor RH Circuit

DTC

C1406

Open or Short in Front Speed Sensor LH Circuit

DESCRIPTION

Refer to DTCs C1401 and C1402 (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1401,C1402; Front Speed Sensor RH Malfunction ).

DTC No.

DTC Detection Condition

Trouble Area

C1405

C1406

Either of the following is detected:

  1. An open in the speed sensor signal circuit continues for 0.5 seconds or more.
  2. With the +BS terminal voltage at 9.5 V or higher, the sensor power supply voltage decreases for 0.5 seconds or more.
  • Front speed sensor RH/LH
  • Speed sensor circuit
  • Skid control ECU (brake actuator assembly)

HINT:

  • DTC C1405 is for the front speed sensor RH.
  • DTC C1406 is for the front speed sensor LH.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: CALIBRATION ).

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 (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: CHECK FOR INTERMITTENT PROBLEMS ).

ABS/VSC/TRAC

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

FR Speed Open

Front speed sensor RH open detection / Error or Normal

Error: Momentary interruption

Normal: Normal

-

FL Speed Open

Front speed sensor LH open detection / Error or Normal

Error: Momentary interruption

Normal: Normal

-

OK:

There are no momentary interruptions.

HINT:

Perform the above inspection before removing the sensor and connector.

NG

GO TO STEP 4

OK

2.

READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Start the engine.

(d) Turn the Techstream on.

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

(f) Select the Data List using the Techstream (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DATA LIST / ACTIVE TEST ).

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 (202 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 (202 mph)

Vehicle stopped: 0 km/h (0 mph)

When driving at constant speed: No large fluctuations

(g) 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 pressure, 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 (See page 2018 - 2020 MY Sienna [11/2017 -        ]; METER / GAUGE / DISPLAY: METER / GAUGE SYSTEM: 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

GO TO STEP 4

OK

3.

RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR ).

(c) Turn the ignition switch off.

(d) Start the engine.

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

(f) Check if the same DTC is output (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR ).

Result

Proceed to

DTCs C1405 and C1406 are not output.

A

DTCs C1405 and/or C1406 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 (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE ).

A

CHECK FOR INTERMITTENT PROBLEMS

B

REPLACE BRAKE ACTUATOR ASSEMBLY

4.

CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - FRONT SPEED SENSOR)

(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.

(c) Disconnect the A75 skid control ECU (brake actuator assembly) connector.

(d) Disconnect the A20 or A6 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

A75-31 (FR+) - A20-2 (FR+)

Always

Below 1 Ω

A75-31 (FR+) - Body ground

Always

10 kΩ or higher

A75-30 (FR-) - A20-1 (FR-)

Always

Below 1 Ω

A75-30 (FR-) - Body ground

Always

10 kΩ or higher

for LH

Tester Connection

Condition

Specified Condition

A75-18 (FL+) - A6-2 (FL+)

Always

Below 1 Ω

A75-18 (FL+) - Body ground

Always

10 kΩ or higher

A75-17 (FL-) - A6-1 (FL-)

Always

Below 1 Ω

A75-17 (FL-) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.

INSPECT BRAKE ACTUATOR ASSEMBLY (SENSOR INPUT)

(a) Reconnect the A75 skid control ECU (brake actuator assembly) connector.

(b) Turn the ignition switch to ON.

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

Standard Voltage:

for RH

Tester Connection

Switch Condition

Specified Condition

A20-2 (FR+) - Body ground

Ignition switch ON

8 to 14 V

for LH

Tester Connection

Switch Condition

Specified Condition

A6-2 (FL+) - Body ground

Ignition switch ON

8 to 14 V

NOTICE:

Check the speed sensor signal after replacement (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: 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 (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE ).

Text in Illustration

*a

Front view of wire harness connector

(to Front Speed Sensor)

OK

REPLACE SPEED SENSOR FRONT RH

NG

REPLACE BRAKE ACTUATOR ASSEMBLY