Toyota 4Runner: Lost Communication with ECM / PCM "A" (U0100,U0126,U0129)

Toyota 4Runner Service Manual / Steering / Power Assist Systems / Power Steering System / Lost Communication with ECM / PCM "A" (U0100,U0126,U0129)

DESCRIPTION

The power steering ECU assembly receives signals from the ECM, steering angle sensor and master cylinder solenoid (skid control ECU) via the CAN communication system.

DTC Code	DTC Detection Condition	Trouble Area
U0100	The engine speed signal is lost.	CAN communication system
U0126	The steering angle signal is lost.	CAN communication system
U0129	The vehicle speed signal is lost.	CAN communication system

PROCEDURE

1.	CHECK FOR DTC (CAN COMMUNICATION SYSTEM)

(a) Clear the DTCs (See page ).

(b) Check for DTCs (See page ).

Result

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

USE SIMULATION METHOD TO CHECK

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

Steering Angle Sensor Circuit (C15F1)

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Vehicle Speed Signal (C1541)

DESCRIPTION The power steering ECU assembly receives vehicle speed signals from the master cylinder solenoid (skid control ECU) via CAN communication. The power steering ECU assembly provides app ...

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