Toyota 4Runner: Acceleration Sensor Power Supply Voltage Malfunction (C1381)

Toyota 4Runner Service Manual / Brake / Brake Control / Dynamic Control Systems / Vehicle Stability Control System(for Hydraulic Brake Booster) / Acceleration Sensor Power Supply Voltage Malfunction (C1381)

DESCRIPTION

The skid control ECU receives signals from the yaw rate and acceleration sensor 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).

If there is trouble in the bus lines between the yaw rate and acceleration sensor and the CAN communication system, DTCs U0123 (malfunction in CAN communication with the yaw rate sensor) and U0124 (malfunction in CAN communication with the acceleration sensor) are stored.

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

DTC Code	DTC Detection Condition	Trouble Area
C1381	At a vehicle speed of more than 3 km/h (2 mph), the acceleration sensor power source malfunction signal is received for 10 seconds or more.	Yaw rate and acceleration sensor Yaw rate and acceleration sensor power source circuit

WIRING DIAGRAM

Refer to DTCs C1232, C1243 and C1245 (See page ).

CAUTION / NOTICE / HINT

NOTICE:

When replacing the yaw rate and acceleration sensor, perform calibration (See page ).

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.	CHECK DTC (CAN COMMUNICATION SYSTEM)

(a) Check for DTCs (See page ).

Result

Result	Proceed to
CAN DTC is not output	A
CAN DTC is output	B

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

2.	CHECK TERMINAL VOLTAGE (IG)

(a) Disconnect the F36 yaw rate and acceleration sensor connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
F36-4 (IG) - Body ground	Engine switch on (IG)	11 to 14 V

Text in Illustration

*a	Front view of wire harness connector (to Yaw Rate and Acceleration Sensor)

REPAIR OR REPLACE HARNESS OR CONNECTOR (IG CIRCUIT)

3.	CHECK HARNESS AND CONNECTOR (GND TERMINAL)

(a) Disconnect the F36 yaw rate and acceleration sensor connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
F36-1 (GND) - Body ground	Always	Below 1 Ω

NOTICE:

Check the yaw rate and acceleration sensor signal after replacement (See page ).

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

4.	RECONFIRM DTC

(a) Reconnect the yaw rate and acceleration sensor connector.

(b) Clear the DTCs (See page ).

(d) Perform a road test.

(e) Check if the same DTC is output (See page
).

Result

Result	Proceed to
DTC C1381 is not output	A
DTC C1381 is output	B

USE SIMULATION METHOD TO CHECK

REPLACE YAW RATE SAND ACCELERATION SENSOR

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