Toyota RAV4 Service Manual: Ecm communication circuit malfunction

Description

The circuit is used to send trc and vsc control information from the skid control ecu to the ecm, and engine control information from the ecm to the skid control ecu.

Inspection procedure

Hint:

Check that the part numbers of the installed ecm and skid control ecu are correct before performing the following procedure.

1. Reconfirm dtc

1. Clear the dtc (see page bc-47).
2. Start the engine.
3. Check if the same dtc is output (see page bc-47).

Result

Replace ecm

Zero point calibration

Description

The abs and traction actuator (skid control ecu) receives signals from the yaw rate and deceleration sensor via the can communication system. The yaw rate sensor has a built-in deceleration sensor and detects the vehicle's condition using 2 circuits (gl1, gl2). If there are problems in the bus lines between the yaw rate and deceleration sensor and the can communication system, dtcs u0123/62 (yaw rate sensor communication trouble) and u0124/95 (deceleration sensor communication trouble) are output.

The dtcs are also output when the calibration has not been completed.

Wiring diagram

Inspection procedure

Notice:

When replacing the abs and traction actuator, perform the zero point calibration (see page bc- 24).

Hint

When dtc u0123/62, u0124/95 or u0126/63 is output together with dtc c1210/36 or c1336/39, inspect and repair trouble areas indicated by dtc u0123/62, u0124/95 or u0126/63 first.

1. Check yaw rate sensor installation

1. Check that the yaw rate sensor has been installed properly (see page bc-211).

Ok: the sensor is tightened to the specified torque.

The sensor is not tilted.

2. Perform zero point calibration of yaw rate sensor

1. Perform zero point calibration of the yaw rate and deceleration sensor (see page bc-24).

3. Reconfirm dtc

1. Clear the dtc(s) (see page bc-47).
2. Start the engine.
3. Drive the vehicle and turn the steering wheel to the right and left at a speed of 45 km/h (28 mph) or more.
4. Check if the same dtc(s) is recorded (see page bc- 47).

Result

Hint:

• The dtc(s) is set if the zero point calibration has not been completed successfully.
• End the procedure when the same dtc(s) is not set after completion of the zero point calibration.

Replace abs and traction actuator assembly