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
U0073-00	Control module comm Bus A Off (Control module communication Bus A Off)	[NO SUBTYPE INFO]	Diagnosis condition	When ignition 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

When CAN communication with ECM and BCM is impossible, IPDM E/R performs fail-safe control. After CAN communication recovers normally, it also returns to normal control.

If No CAN Communication Is Available With ECM

Control part	Fail-safe operation
Cooling fan	The cooling fan is operated at HI operation when the ignition switch is turned ON. Turn OFF the cooling fan operation when the ignition switch is turned OFF.
A/C compressor	A/C compressor OFF

If No CAN Communication Is Available With BCM

Control part	Fail-safe operation
Headlight	Turns ON the headlight (LO) when the ignition switch is turned ON. Turns OFF the headlight (LO) when the ignition switch is turned OFF. Headlight (HI): OFF
Parking light License plate light Tail light Side marker light Illumination	Turns ON the tail light, parking light, license plate light, side marker light and each illumination when the ignition switch is turned ON. Turns OFF the tail light, parking light, license plate light, side marker light and each illumination when the ignition switch is turned OFF.
Front wiper	The status just before activation of fail-safe control is maintained until the ignition switch is turned OFF while the front wiper is operating at LO or HI speed. The wiper is operated at LO speed until the ignition switch is turned OFF if the fail-safe control is activated while the front wiper is set in the INT mode and the front wiper motor is operating.
Daytime running light	Daytime running light: OFF
Front fog light	Front fog light: OFF
Ignition relay	The status just before activation of fail-safe is maintained.
Starter motor	Starter relay: OFF

DTC CONFIRMATION PROCEDURE

1.PERFORM DTC CONFIRMATION PROCEDURE

With M.U.T.-III SE

Ignition switch ON and wait for 2 seconds or more.
Check “Self Diagnostic Result” 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