Toyota Tacoma (2015-2018) Service Manual: Acceleration Sensor Power Supply Voltage Malfunction (C1381)

Toyota Tacoma (2015-2018) Service Manual / Brake Control / Dynamic Control Systems / Vehicle Stability Control System(for Vacuum Brake Booster) / Acceleration Sensor Power Supply Voltage Malfunction (C1381)

DESCRIPTION

The skid control ECU (brake actuator assembly) receives signals from the yaw rate and acceleration sensor (airbag sensor assembly) via the CAN communication system.

The airbag sensor assembly has a built-in acceleration sensor and detects the vehicle condition.

If there is trouble in the bus lines between the acceleration sensor (airbag sensor assembly) and the CAN communication system, the DTC U0124 (Lost Communication with Lateral Acceleration Sensor Module) is output.

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

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1381	Acceleration Sensor Power Supply Voltage Malfunction	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.	A/BAG fuse Acceleration sensor (Airbag sensor assembly) Wire harness or connector

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 ).
When replacing the yaw rate and acceleration sensor (airbag sensor assembly), perform zero point calibration and store system information (See page ).
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.	CHECK TERMINAL VOLTAGE (IG2 TERMINAL)

NOTICE:

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work (See page ).
When disconnecting the cable, some systems need to be initialized after the cable is reconnected (See page ).

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

(d) Disconnect the A21 yaw rate and acceleration sensor (airbag sensor assembly) connector.

(e) Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

(f) Turn the ignition switch to ON.

(g) Operate all the components of the electrical system (defogger, wipers, headlights, heater blower, etc.).

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A21-21 (IG2) - Body ground	Ignition switch ON	11 to 14 V

Text in Illustration

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

REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2 CIRCUIT)

2.	CHECK HARNESS AND CONNECTOR (GND TERMINAL)

(a) Turn the ignition switch off.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A21-25 (E1) - Body ground	Always	Below 1 Ω
A21-26 (E2) - Body ground	Always	Below 1 Ω

Text in Illustration

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

HINT:

If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step (See page ).

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

3.	RECONFIRM DTC

(a) Reconnect the A21 yaw rate and acceleration sensor (airbag sensor assembly) connector.

(b) Clear the DTC (See page (c) Turn the ignition switch off. ).

(d) Start the engine.

(e) Perform a road test.

(f) Check if the same DTC is recorded (See page Result Result ).

Result

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

USE SIMULATION METHOD TO CHECK

REPLACE AIRBAG SENSOR ASSEMBLY

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