Toyota Tacoma 2015-2018 Service Manual: Motor Malfunction (C1427)

Toyota Tacoma 2015-2018 Service Manual / Brake Control / Dynamic Control Systems / Vehicle Stability Control System(for Vacuum Brake Booster) / Motor Malfunction (C1427)

DESCRIPTION

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1427	Motor Malfunction	Actuator pump motor does not operate properly.	Brake actuator assembly (Ground circuit) Brake actuator assembly (Motor circuit) Wire harness or connector

WIRING DIAGRAM

Refer to DTCs C142B, C146C and C146D (See page CAUTION / NOTICE / HINT ).

CAUTION / NOTICE / HINT

NOTICE:

When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information (See page PROCEDURE ).

PROCEDURE

1.	PERFORM ACTIVE TEST USING TECHSTREAM (MOTOR RELAY)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.

(e) According to the display on the Techstream, perform the Active Test.

ABS/VSC/TRAC

Tester Display	Measurement Item	Control Range	Diagnostic Note
Motor Relay	Motor relay	Relay ON / OFF	Operating sound of motor can be heard. Vehicle condition: Vehicle stopped

Tester Display

Measurement Item

Control Range

Diagnostic Note

Motor Relay

Motor relay

Relay ON / OFF

Operating sound of motor can be heard.

Vehicle condition: Vehicle stopped

(f) Check the operating sound of the motor relay when operating it with the Techstream.

Result

Result	Proceed to
The operating sound is not heard	A
The operating sound is heard	B

GO TO STEP 3

2.	CHECK HARNESS AND CONNECTOR (GND2 TERMINAL)

(a) Turn the ignition switch off.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
S1-1 (GND2) - Body ground	Always	Below 1 Ω

Text in Illustration

*a	Front view of wire harness connector (to Skid Control ECU [Brake Actuator Assembly])

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND2 CIRCUIT)

3.	RECONFIRM DTC

HINT:

This code is detected when a problem is identified in the brake actuator assembly. The motor relay is in the brake actuator assembly.

Therefore, motor relay unit inspection cannot be performed. Be sure to check if the DTC is output before replacing the brake actuator assembly.

(a) Reconnect the S1 skid control ECU (brake actuator assembly) connector.

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

(d) Start the engine.

(e) Drive the vehicle at a speed of 20 km/h (12 mph) or more for 30 seconds or more.

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

HINT:

If a speed signal of 6 km/h (4 mph) or more is input to the skid control ECU (brake actuator assembly) with the ignition switch to ON and the stop light switch off, the ECU performs self diagnosis of the motor and solenoid circuits.
If the normal system code is output (no trouble codes are output), slightly jiggle the connectors, wire harness, and fuses of the brake actuator assembly. Make sure that no DTCs are output.
If any DTCs are output while jiggling a connector or wire harness of the skid control ECU (brake actuator assembly), inspect and repair the connector or wire harness.
The DTCs were probably output due to a bad connection of the connector terminal.

Result

Result	Proceed to
DTC C1427 is not output	A
DTC C1427 is output	B

USE SIMULATION METHOD TO CHECK

REPLACE BRAKE ACTUATOR ASSEMBLY

Stop Light Switch OFF Stuck Malfunction (C1426)

DESCRIPTION The skid control ECU (brake actuator assembly) inputs the stop light signal and brake operation condition. When the brake pedal is depressed and the stop light switch signal is not in ...

Motor Power Supply Voltage Circuit (C142B-C146D)

DESCRIPTION The motor relay and motor fail-safe relay are built into the brake actuator assembly. During ABS, TRAC, VSC, or brake assist operation, the skid control ECU (brake actuator assembly) t ...

Other materials:

Precaution
PRECAUTION 1. IGNITION SWITCH EXPRESSIONS (a) The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this section. Expression Ignition Switch (Position) Engine ...

Downhill Assist Control system
The downhill assist control system helps to prevent excessive speed on steep downhill descents. ■ System operation The system will operate when the vehicle is traveling under 15 mph (25 km/h) and the front-wheel drive control switch is in the L4 position. Press the DAC switch. The ind ...

Installation
INSTALLATION CAUTION / NOTICE / HINT HINT: Use the same procedures for both the LH and RH sides. The procedure described below is for the LH side. PROCEDURE 1. INSTALL OUTER REAR VIEW MIRROR ASSEMBLY (a) Engage the claw to install the outer rear view mirror assembly. (b) Ins ...