Toyota 4Runner: Lost Communication with ECM / PCM (U0100,U0129,U0142,U0155)

Toyota 4Runner Service Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Smart Key System(for Start Function) / Lost Communication with ECM / PCM (U0100,U0129,U0142,U0155)

DESCRIPTION

The power management control ECU receives information from 2 sources. It receives information via a direct line and via the CAN communication line. If the information from these 2 sources is inconsistent, this DTC is stored.

HINT:

When the power management control ECU is replaced with a new one and the cable is connected to the negative (-) battery terminal, the power source mode is reset to on (IG). When the battery is removed and reinstalled, the power source mode that was selected when the battery was removed is restored.

DTC Code	DTC Detection Condition	Trouble Area
U0100	There is no communication from the ECM.	CAN communication system ECM
U0142	There is no communication from the main body ECU.	CAN communication system Main body ECU (Driver side junction block assembly)
U0129	There is no communication from the skid control ECU.	CAN communication system Skid control ECU
U0155	There is no communication from the combination meter.	CAN communication system Combination meter assembly

PROCEDURE

1.	CHECK FOR DTC

(a) Check for DTCs and note any codes that are output (See page ).

(b) Clear the 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)

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