Engine Control System: FAILSAFE

NON DTC RELATED ITEM

Detected items	Engine operating condition in fail-safe mode	Remarks	Reference
Malfunction indicator lamp circuit	Engine speed will not rise more than 2, 500 RPM due to the fuel cut	When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when there is malfunction on engine control system. Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means of operating fail safe function. The fail safe function also operates when above diagnoses except MIL circuit are detected and demands the driver to repair the malfunction.	COMPONENT FUNCTION CHECK

DTC RELATED ITEM

DESCRIPTION

When a DTC is detected, ECM executes a mode (in the Fail-safe mode) applicable to the DTC. The fail-safe mode has the preset traveling control mode (accelerator angle variation and engine output limit) and device fix 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.
Device fix mode		This mode fixes the IVT control solenoid valve and the EVT control solenoid valve in the reference position. The intake manifold runner control valve motor is turned OFF (intake manifold runner control valve opens).

FAIL SAFE PATTERN

Pattern	Fail safe mode
A	Traveling control mode	Accelerator angle variation control
B	Traveling control mode	Engine output control
C	Device fix mode

FAIL SAFE LIST

:Applicable : Not applicable

DTC No.	Detected items	Vehicle behavior
		Pattern			Others
		A	B	C	Others
P0011	Intake valve timing control	-	-	*	ECM activates the IVT intermediate lock control solenoid valve to bring the cam sprocket into an intermediate lock condition.
P0014 P0078	Exhaust valve timing control	-	-	*	-
P0101 P0102 P0103	Mass air flow sensor circuit	*	*	*	-
P0122 P0123 P0222 P0223 P2135	Throttle position sensor	-	-	-	The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10 degrees. The ECM regulates the opening speed of the throttle valve to be slower than the normal condition. So, the acceleration will be poor.
P0171 P0172	Fuel injection system	*	-	-	-
P0197 P0198	Engine oil temperature sensor	-	-	-	Exhaust valve timing control does not function.
P0300 P0301 P0302 P0303 P0304	Misfire	*	-	-	-
P0500	Vehicle speed sensor	*	-	-	-
P050A	Cold start control	*	-	-	-
P0524	Engine oil pressure	-	-	-	ECM illuminates oil pressure warning lamp on the combination meter. Engine speed will not rise more than 4, 000 RPM due to the fuel cut. Fail-safe is canceled when ignition switch OFF → ON.
P052A P052B	Intake valve timing intermediate lock control	-	-	*	-
P0603	ECM power supply circuit	-	*	-	-
P0605	ECM	-	*	-	-
P0643	Sensor power supply	-	-	-	ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P1078	Exhaust valve timing control position sensor circuit	*	-	*	-
P1805	Brake switch	-	-	-	ECM controls the electric throttle control actuator by regulating the throttle opening to a small range. Therefore, acceleration will be poor.
					Vehicle condition	Driving condition
					When engine is idling	Normal
					When accelerating	Poor acceleration
P2004	Intake manifold runner control valve	-	*	*	-
P2100 P2103	Throttle control motor relay	-	-	-	ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2101	Electric throttle control function	-	-	-	ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2118	Throttle control motor	-	-	-	ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2119	Electric throttle control actuator	-	*	-	-
P2122 P2123 P2127 P2128 P2138	Accelerator pedal position sensor	-	-	-	The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10 degrees. The ECM regulates the opening speed of the throttle valve to be slower than the normal condition. So, the acceleration will be poor.