DTC Description

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, 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	CONSULT screen terms (Trouble diagnosis content)	DTC detection condition
U0122	VDC MDL (Lost communication with vehicle dynamics control module)	Diagnosis condition	Ignition switch ON
		Signal (terminal)	CAN communication signal
		Threshold	When ECM is not transmitting or receiving CAN communication signal of OBD (emission related diagnosis) with ABS actuator and electric unit (control unit)
		Diagnosis delay time	2 seconds or more

POSSIBLE CAUSE

Harness or connectors (CAN communication line is open or shorted)

FAIL-SAFE

Engine operating condition in fail-safe mode
Fail safe mode		Vehicle behavior
Traveling control mode	Accelerator angle variation control	ECM controls the accelerator pedal depression speed to make it slower than actual speed. This causes a drop in accelerating performance and encourages the driver to repair malfunction. NOTE: ECM does not control the accelerator pedal releasing speed.
Traveling control mode	Engine output control	ECM reduces the engine output, according to the rise in engine speed. This reduces the vehicle speed to encourage the driver to repair malfunction.Driving at 40 km/h (25 MPH) or more is possible. NOTE: This value is a reference value converted from engine power to vehicle speed. Actual power limitation value differs due to the malfunctioning part and driving condition.

DTC CONFIRMATION PROCEDURE

PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 3 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?

YES>>

Refer to DTC Diagnosis Procedure .

NO-1>>

To check malfunction symptom before repair: Refer to Intermittent Incident .

NO-2>>

Confirmation after repair: INSPECTION END