DTC Description

CAN (Controller Area Network) is a serial communication line for real time applications. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Modern vehicle is equipped with many electronic control unit, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

DTC DETECTION LOGIC

DTC No.	M.U.T.-III SE screen items (Trouble diagnosis content)		DTC detection condition
U2153-87	CAN comm err (HVAC) [Controller area network communication error (Heating ventilating and air-conditioning system)]	[MISSING MESSAGE]	Diagnosis condition	When electric motor switch is ON.
			Signal (terminal)	CAN communication signal
			Threshold	When IPDM E/R cannot communicate CAN communication signal
			Diagnosis delay time	2 seconds or more

POSSIBLE CAUSE

CAN communication system

FAIL-SAFE

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DTC CONFIRMATION PROCEDURE

1.PERFORM DTC CONFIRMATION PROCEDURE

With M.U.T.-III SE

Electric motor switch ON and wait for 2 seconds or more.
Check "Diagnostic Trouble Code" of “IPDM E/R” using M.U.T.-III SE.

Is DTC detected?

Refer to Diagnosis Procedure

-1 To check malfunction symptom before repair: Refer to Intermittent IncidentIntermittent Incident

-2 Confirmation after repair: INSPECTION END