Electronically Controlled Brake System

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1234/34, C1243/43-C1245/45, C1279/79, C1381/97: Yaw Rate Sensor Malfunction
C1381/97 - Acceleration Sensor Power Supply Voltage Malfunction

DESCRIPTION

The skid control ECU receives signals from the yaw rate and acceleration sensor (for separate type) or yaw rate and acceleration sensor (airbag sensor assembly) (for built-in type) via the CAN communication system.

The yaw rate sensor has a built-in acceleration sensor and detects the vehicle's condition using 2 circuits (GL1, GL2) (for separate type).

The airbag sensor assembly has a built-in yaw rate and acceleration sensor and detects the vehicle's condition using 2 circuits (GL1, GL2) (for built-in type).

If there are any problems in the bus lines between the yaw rate and acceleration sensor (for separate type) or yaw rate and acceleration sensor (airbag sensor assembly) (for built-in type) and the CAN communication system, DTCs U0123/62 (Lost Communication with Yaw Rate Sensor Module) and U0124/95 (Lost Communication with Lateral Acceleration Sensor Module) are stored.

These DTCs are also output when calibration has not been completed.

DTC C1279/79 will be cleared when the yaw rate and acceleration sensor (for separate type) or yaw rate and acceleration sensor (airbag sensor assembly) (for built-in type) sends a yaw rate and/or acceleration signal or when Test Mode ends. DTC C1279/79 is output only in Test Mode.

WIRING DIAGRAM

1. for Separate Type

2. for Built-in Type

INSPECTION PROCEDURE

NOTICE:
When replacing the yaw rate and acceleration sensor (for separate type) or yaw rate and acceleration sensor (airbag sensor assembly) (for built-in type), perform zero point calibration Calibration.

HINT
When U0123/62 and/or U0124/95 is output together with C1234/34, C1243/43, C1244/44, C1245/45, and/or C1381/97, inspect and repair the trouble areas indicated by U0123/62 and/or U0124/95 first Electronically Controlled Brake System.

PROCEDURE

1. CHECK DTC

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

(b) Turn the power switch off.

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

(d) Drive the vehicle at a speed of 30 km/h (19 mph) or more, turn the steering wheel, and decelerate (depress the brake pedal) the vehicle.

(e) Turn the power switch on (IG) again and check that no CAN communication system DTC is output Diagnosis System.

(f) Check if DTC C1210/36 (Zero Point Calibration of Yaw Rate Sensor Undone) or C1336/98 (Zero Point Calibration of Acceleration Sensor Undone) is output Reading and Clearing Diagnostic Trouble Codes.

Result:

B -- CHECK AIRBAG SENSOR ASSEMBLY INSTALLATION

C -- INSPECT CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting

D -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Electronically Controlled Brake System
A -- Continue to next step.

2. CHECK YAW RATE AND ACCELERATION SENSOR INSTALLATION

(a) Turn the power switch off.

(b) Check that the yaw rate and acceleration sensor has been installed properly Installation.

OK:

The sensor is tightened to the specified torque.

The sensor is not tilted.

NG -- INSTALL YAW RATE AND ACCELERATION SENSOR CORRECTLY Installation
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (IG TERMINAL)

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

(b) Disconnect the yaw rate and acceleration sensor connector.

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

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

Standard Voltage:

Text in Illustration

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IG CIRCUIT)
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (GND TERMINAL)

(a) Turn the power switch off.

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

Standard Resistance:

Text in Illustration

NOTICE:
Check the yaw rate and acceleration sensor signal after replacement 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 Problem Symptoms Table.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

OK -- REPLACE YAW RATE AND ACCELERATION SENSOR Removal

5. CHECK AIRBAG SENSOR ASSEMBLY INSTALLATION

(a) Turn the power switch off.

(b) Check that the yaw rate and acceleration sensor (airbag sensor assembly) has been installed properly Installation.

OK:

The sensor is tightened to the specified torque.

The sensor is not tilted.

NG -- INSTALL AIRBAG SENSOR ASSEMBLY CORRECTLY Installation
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (IG2 TERMINAL)

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

(b) Disconnect the yaw rate and acceleration sensor (airbag sensor assembly) connector.

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

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

Standard Voltage:

Text in Illustration

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2 CIRCUIT)
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (E TERMINAL)

(a) Turn the power switch off.

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

Standard Resistance:

Text in Illustration