Toyota Tacoma (2015-2018) Service Manual: Lost Communication with ECM (C1437)

Toyota Tacoma (2015-2018) Service Manual / Brake Control / Dynamic Control Systems / Vehicle Stability Control System(for Vacuum Brake Booster) / Lost Communication with ECM (C1437)

DESCRIPTION

The skid control ECU (brake actuator assembly) receives signals from the ECM via the CAN communication system.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1437	Lost Communication with ECM	When voltage at terminal +BS is 10 to 17.4 V and vehicle speed is 15 km/h (9 mph) or more, data cannot be sent to ECM continuously for 2 seconds or more.	CAN communication system (skid control ECU to ECM) Skid control ECU (brake actuator assembly) ECM

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.	CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

(a) Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to the DTC (See page ABS/VSC/TRAC ).

ABS/VSC/TRAC

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
EFI Communication Open	EFI communication open detection	Normal or Error	Normal	Error: Momentary interruption
EFI Communication Invalid	ECM communication invalid detection	Normal or Error	Normal	Error: Invalid

HINT:

Perform the above inspection before removing the sensor and connector.

OK:

Normal (There are no momentary interruptions.)

CHECK CAN COMMUNICATION SYSTEM

2.	RECONFIRM DTC

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

(b) Turn the ignition switch off.

(d) Drive the vehicle at a speed of 15 km/h (9 mph) or more for 10 seconds or more.

(e) Check that no CAN communication system DTC is output (See page (f) Check if the same DTC is recorded (See page ).

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

Result

Result	Proceed to
DTC C1437 is not output	A
DTC C1437 is output	B
CAN communication system DTC is output	C

USE SIMULATION METHOD TO CHECK

REPLACE BRAKE ACTUATOR ASSEMBLY

CHECK CAN COMMUNICATION SYSTEM

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