Toyota RAV4 (XA40) 2013-2018 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.
- Reconfirm dtc
- Clear the dtc (see page bc-47).
- Start the engine.
- 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.
- Check yaw rate sensor installation
- 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.
- Perform zero point calibration of yaw rate sensor
- Perform zero point calibration of the yaw rate and deceleration sensor (see page bc-24).
- Reconfirm dtc
- Clear the dtc(s) (see page bc-47).
- Start the engine.
- Drive the vehicle and turn the steering wheel to the right and left at a speed of 45 km/h (28 mph) or more.
- 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
Engine control system malfunction
Description
If a malfunction in the engine control system is detected, the operations of
vsc and trc are prohibited
by the fail-safe function. When the signals from the engine are input normal ...
Abs control system malfunction
Description
This dtc is output when the vsc system detects a malfunction in the abs
system.
Inspection procedure
Check dtc for abs system
Clear the dtc (see page bc-47).
Turn t ...
Other materials:
Check and replace ecu
Notice:
The connector should not be disconnected from
the ecu. Perform the inspection from the
backside of the connector on the wire harness
side.
When no measuring condition is specified,
perform the inspection with the engine stopped
and the ignition switch on.
Check that the con ...
Hill-start assist control
When the engine is stopped by
the Stop & Start system when
the vehicle is on an incline,
when the brake pedal is
released, brake force is temporarily
maintained to prevent the
vehicle from rolling backwards
before the engine is restarted
and drive force is generated.
When drive force is generat ...
Driving in vehicle-to-vehicle distance control mode
This mode employs a radar to detect the presence of vehicles up to
approximately 328 ft. (100 m) ahead, determines the current vehicle-to-
vehicle following distance, and operates to maintain a suitable following
distance from the vehicle ahead. The desired vehicle-to-vehicle
distance can also be se ...
