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

Toyota 4Runner Service Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System(for Manual Air Conditioning System) / Lost Communication with ECM (U0100,U0142,U0155)

DESCRIPTION

The air conditioning amplifier communicates with the ECM, main body ECU (multiplex network body ECU) and combination meter through the CAN communication system.

DTC Code	DTC Detection Condition	Trouble Area
U0100	Lost communication with the ECM.	CAN communication system ECM
U0142	Lost communication with the main body ECU.	CAN communication system Main body ECU (multiplex network body ECU)
U0155	Lost communication with the combination meter.	CAN communication system Combination meter assembly

PROCEDURE

1.	CHECK FOR DTC (CAN COMMUNICATION SYSTEM)

(a) Use the Techstream to check if the CAN communication system is functioning normally.

Result

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

USE SIMULATION METHOD TO CHECK

GO TO CAN COMMUNICATION SYSTEM

Compressor Lock Sensor Circuit (B1422)

SYSTEM DESCRIPTION The ECM sends the engine speed signal to the air conditioning amplifier assembly via CAN communication. The air conditioning amplifier assembly reads the difference between comp ...

Air Outlet Damper Control Servo Motor Circuit (B1443)

DESCRIPTION The damper servo sub-assembly (mode damper servo) sends pulse signals to inform the No. 1 air conditioning amplifier assembly of the damper position. The No. 1 air conditioning amplif ...

Other materials about Toyota 4Runner:

Dtc Check / Clear
DTC CHECK / CLEAR 1. CHECK DTC (a) Connect the Techstream to the DLC3. (b) Turn the engine switch on (IG). (c) Turn the Techstream on. (d) Enter the following menus: Body Electrical / Smart Key / Trouble Codes. (e) Check for DTCs. 2. CLEAR DTC (a) Conn ...

Reassembly
REASSEMBLY CAUTION / NOTICE / HINT HINT: Use the same procedure for the RH and LH sides. The procedure listed below is for the LH side. PROCEDURE 1. TEMPORARILY INSTALL FRONT DISC BRAKE BLEEDER PLUG (a) Temporarily install the front dis ...