DIAGNOSIS FUNCTION

ENGINE WARNING LAMP (CHECK ENGINE LAMP)

If an abnormality occurs in any of the following items related to the Multipoint Fuel Injection (MPI) system, the engine warning lamp will illuminate.If the lamp remains illuminated or if the lamp illuminates while the engine is running, check the diagnosis code output.The lamp illuminates for approximately 5 seconds to check for burnt-out bulb after the ignition key is turned to the ON position.

ENGINE WARNING LAMP INSPECTION ITEMS

P0031	Right bank oxygen sensor (front) heater circuit low input
P0032	Right bank oxygen sensor (front) heater circuit high input
P0037	Right bank oxygen sensor (rear) heater circuit low input
P0038	Right bank oxygen sensor (rear) heater circuit high input
P0051	Left bank oxygen sensor (front) heater circuit low input
P0052	Left bank oxygen sensor (front) heater circuit high input
P0057	Left bank oxygen sensor (rear) heater circuit low input
P0058	Left bank oxygen sensor (rear) heater circuit high input
P0102*	Air flow sensor circuit low input
P0103*	Air flow sensor circuit high input
P0107	Manifold absolute pressure sensor circuit low input
P0108	Manifold absolute pressure sensor circuit high input
P0112*	Intake air temperature sensor circuit low input
P0113*	Intake air temperature sensor circuit high input
P0117*	Engine coolant temperature sensor circuit low input
P0118*	Engine coolant temperature sensor circuit high input
P0122*	Throttle position sensor (main) circuit low input
P0123*	Throttle position sensor (main) circuit high input
P0125*	Insufficient coolant temperature for closed loop fuel control
P0131	Right bank oxygen sensor (front) circuit low voltage
P0132	Right bank oxygen sensor (front) circuit high voltage
P0133	Right bank oxygen sensor (front) circuit slow response
P0134*	Right bank oxygen sensor (front) circuit no activity detected
P0137	Right bank oxygen sensor (rear) circuit low voltage
P0138	Right bank oxygen sensor (rear) circuit high voltage
P0151	Left bank oxygen sensor (front) circuit low voltage
P0152	Left bank oxygen sensor (front) circuit high voltage
P0153	Left bank oxygen sensor (front) circuit slow response
P0154*	Left bank oxygen sensor (front) circuit no activity detected
P0157	Left bank oxygen sensor (rear) circuit low voltage
P0158	Left bank oxygen sensor (rear) circuit high voltage
P0171	Right bank abnormal fuel system (lean)
P0172	Right bank abnormal fuel system (rich)
P0174	Left bank abnormal fuel system (lean)
P0175	Left bank abnormal fuel system (rich)
P0201	No. 1 injector system
P0202	No. 2 injector system
P0203	No. 3 injector system
P0204	No. 4 injector system
P0205	No. 5 injector system
P0206	No. 6 injector system
P0222*	Throttle position sensor (sub) circuit low input
P0223*	Throttle position sensor (sub) circuit high input
P0300**	Random/multiple cylinder misfire detected
P0301**	No. 1 cylinder misfire detected
P0302**	No. 2 cylinder misfire detected
P0303**	No. 3 cylinder misfire detected
P0304**	No. 4 cylinder misfire detected
P0305**	No. 5 cylinder misfire detected
P0306**	No. 6 cylinder misfire detected
P0335*	Crank angle sensor system
P0340*	Camshaft position sensor system
P0421	Warm Up Catalyst Malfunction (right bank)
P0431	Warm Up Catalyst Malfunction (left bank)
P0443	Purge control solenoid valve system
P0489	Exhaust gas recirculation valve (stepper motor) circuit malfunction (Ground short) <Except vehicles for Russia>
P0490	Exhaust gas recirculation valve (stepper motor) circuit malfunction (Battery short) <Except vehicles for Russia>
P0603*	EEPROM malfunction
P0606*	Engine-ECU main processor malfunction
P0630*	Chassis number not programmed
P0638*	Throttle valve control servo circuit range/performance problem
P0642*	Throttle position sensor power supply
P0657*	Throttle valve control servo relay circuit malfunction
P1020	Mitsubishi innovative valve timing electronic control system (MIVEC) performance problem
P1021	Oil feeder control valve system
P1233*	Trustful check throttle position sensor (main)
P1234*	Trustful check throttle position sensor (sub)
P1235*	Trustful check air flow sensor
P1236*	A/D converter
P1237*	Trustful check accelerator pedal position sensor
P1238*	Air flow sensor trustful for torque monitoring
P1239	Trustful check engine speed
P1241	Torque monitoring
P1590*	A/T-ECU to engine-ECU communication error in torque reduction request
P1603*	Battery backup circuit malfunction
P1676*	Variant coding system
P2100*	Throttle valve control servo circuit (open)
P2101*	Throttle valve control servo magneto malfunction
P2122*	Accelerator pedal position sensor (main) circuit low input
P2123*	Accelerator pedal position sensor (main) circuit high input
P2127*	Accelerator pedal position sensor (sub) circuit low input
P2128*	Accelerator pedal position sensor (sub) circuit high input
P2135*	Throttle position sensor (main and sub) range/performance problem
P2138*	Accelerator pedal position sensor (main and sub) range/performance problem
P2228*	Barometric pressure sensor circuit low input
P2229*	Barometric pressure sensor circuit high input
P2252	Oxygen sensor offset circuit low voltage
P2253	Oxygen sensor offset circuit high voltage
U0101*	A/T-ECU time-out
U0141*	ETACS-ECU time-out

note

After the engine-ECU has detected a malfunction, the engine warning lamp illuminates when the engine is next turned on and the same malfunction is re-detected. However, for items marked with a "*" in the diagnosis code number column, the engine warning lamp illuminates only on the first detection of the malfunction.

note

For the items marked with a "**", see the following: If the misfire causes the damaged catalyst, the engine-warning lamp illuminates only on the first detection of the malfunction. If the misfire causes exhaust-gas related faults, the engine warning lamp illuminates when the engine is next turned on and the same malfunction is re-detected.

caution

The engine warning lamp continuously illuminates when the engine-ECU malfunctions.

METHOD OF READING AND ERASING DIAGNOSIS CODES

Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - Diagnosis Function

DIAGNOSIS IN DIAGNOSIS SENSITIVITY-UP MODE

When the diagnosis sensitivity-up mode is selected in M.U.T.-III, the engine-ECU illuminates the engine warning lamp and enters into the mode to store the corresponding diagnosis code upon detecting a failure. Time for judgment from occurrence of a malfunction to storing of a diagnosis code is shortened (from 4 seconds to 1 second).This function reduces work for checking a malfunction phenomenon and repair completion after repair. To return to the sensitivity standard mode after selecting the diagnosis sensitivity-up mode, it is necessary either to turn the ignition key to "LOCK" (OFF) or to reselect the sensitivity standard mode on M.U.T.-III. The diagnosis codes and freeze frame data stored in the sensitivity-up mode are automatically erased when the mode is returned to the sensitivity standard mode. If they are needed, record them beforehand.

DIAGNOSIS PROCEDURE

Connect M.U.T.-III and switch the diagnosis mode of the engine-ECU to the diagnosis sensitivity-up mode to perform a test run.
Read the diagnosis code and repair the malfunctioning part.
Select the sensitivity standard mode on M.U.T.-III or turn the ignition switch to the ON position again after turning it to "LOCK" (OFF) position once.

note When the ignition switch is turned to the "LOCK" (OFF) position, the engine-ECU switches the diagnosis mode from diagnosis sensitivity-up mode to diagnosis standard mode.

INSPECTION WITH M.U.T.-III SERVICE DATA AND ACTUATOR TEST

Reading service data or performing an actuator test using M.U.T.-III enables you to check the vehicle body harnesses and components for abnormalities.Sensor input or output to the actuator can be displayed in numerical values or graphs in the service data while in the actuator test the actuator can be forced to drive (ON/OFF driving in the specified time).

DIAGNOSIS PROCEDURE

Connect M.U.T.-III to perform inspection with the service data and actuator test function.
If any abnormality is found, inspect and repair vehicle body harnesses and components.
After repair, check that input and output have returned to normal.
If a failure code which is caused by inspection and repair work is generated, erase the failure code.
Disconnect M.U.T.-III and perform a test run to check that the malfunction phenomenon is resolved.

CHECKING FREEZE FRAME DATA

List of display items of freeze frame data

Item No.	Data Item	Unit·Condition
AA^*2	Air flow sensor	g/s
AB^*2	Throttle position sensor (main)	%
BA^*2	Target exhaust gas recirculation <Except vehicles for Russia>	%
BB^*2	Barometric pressure sensor	kPa
BC	Relative throttle position sensor	%
BD	Throttle position sensor (sub)	%
BE	Accelerator pedal position sensor (main)	%
BF	Accelerator pedal position sensor (sub)	%
C0^*2	Fuel system status 1	CL (closed loop)^3 OL (open loop)^4 OL - Drv (open loop-drive condition)^5 OL -Fault (open loop-system failure)^6 CL -Fault (closed loop-system failure)^*7
C1^2^8	Fuel system status 2	CL (closed loop)^3 OL (open loop)^4 OL - Drv (open loop-drive condition)^5 OL -Fault (open loop-system failure)^6 CL -Fault (closed loop-system failure)^*7
C2^*2	Calculated load valve	%
C3^*2	Engine coolant temperature sensor	°C
C4^*2	Short term fuel trim 1	%
C6*²	Long term fuel trim 1	%
C8^2^8	Short term fuel trim 2	%
CA	Long term fuel trim 2	%
CC^*2	Manifold absolute pressure sensor	kPa
CD^*2	Crank angle sensor	r/min
CE^*2	Vehicle speed	km/h
CF^*2	Advance ignition	°CA
D0^*2	Intake air temperature sensor	°C
D1^*2	Time since engine running^*8	sec
D6^*2	Purge solenoid duty	%
D8	Power supply voltage	V
D9	Absolute load value	%
DA	Target equivalence ratio	-
DB	Intake air temperature sensor	°C
DC	Throttle actuator	%

note

^*1Accumulated time from malfunction detection up to now

note

^*2: Select "Special Function" from the menu screen of M.U.T.-III and then select "Freeze Frame Data" to see these data.However, when malfunctions of multiple systems are detected, the data is stored only for one item first detected.

note

^*3: Condition in which oxygen sensor signals are fed back to the engine-ECU for controlling fuel

note

^*4: Condition in which fuel is controlled without oxygen sensor signals being fed back to the engine-ECU because the condition to shift to the closed loop is not met.

note

^*5: Condition of open loop due to acceleration and deceleration driving

note

^*6: Condition of open loop due to system failure

note

^*7: Condition of closed loop due to system failure

note

^*8: Time between engine start and malfunction detection

FAIL-SAFE AND BACKUP FUNCTION

List of fail-safe and backup function items

Malfunction item	Control content during malfunction
Air flow sensor	Reads the injector basic drive time and basic ignition timing from the preset map using throttle position sensor signals and engine speed signals (crank angle sensor signals).
Manifold absolute pressure sensor	Does not correct the injector drive time corresponding to inlet manifold vacuum pressure. Does not control exhaust gas recirculation <Except vehicles for Russia>.
Intake air temperature sensor	Controls as if the intake air temperature is 25°C.
Engine coolant temperature sensor	Controls as if the engine coolant temperature is 80°C. (Continues this control until the ignition switch is turned to the "LOCK " (OFF) position even if sensor signals return to normal.)
Throttle position sensor (main)	Controls throttle valve position using throttle position sensor (sub) signals. Treats as if the accelerator pedal depressed amount is approximately half opening. Prohibits engine speed feedback control. Cuts off fuel when the engine speed exceeds 3,000 r/min. Stops electronic control throttle valve system to control engine output if throttle position sensor (sub) fails. Prohibits the operation of auto-cruise control <Vehicles with auto-cruise control>.
Oxygen sensor (front)	Does not control air-fuel ratio closed loop.
Oxygen sensor (rear)	Controls air-fuel ratio closed loop using only oxygen sensor (front) signals.
Misfire detection	The engine-ECU stops supplying fuel to the cylinder with the highest misfire rate if a misfire that could damage the catalytic converter is detected.
Ignition coil (power transistor)	Shuts off fuel injection to damaged coil cylinders.
Accelerator pedal position sensor (main)	Detects accelerator pedal depressed amount using throttle position sensor (sub) signals. Treats as if it is approximately half of what it is when normal. Cuts off fuel when the engine speed exceeds 3,000 r/min. Stops electronic control throttle valve system to control engine output if accelerator pedal position sensor (sub) fails. Prohibits the operation of auto-cruise control <Vehicles with auto-cruise control>.
Throttle position sensor (sub)	Controls throttle valve position using throttle position sensor (main) signals. Treats as if the accelerator pedal depressed amount is approximately half opening. Cuts off fuel when the engine speed exceeds 3,000 r/min. Stops electronic control throttle valve system to control engine output if throttle position sensor (main) fails. Prohibits the idle speed control from learning. Prohibits the operation of auto-cruise control <Vehicles with auto-cruise control>
Ignition coil (power transistor)	Shuts off fuel injection to misfiring cylinders.
Camshaft position sensor	Controls by continuing the condition before malfunction determination. Cut off fuel after the lapse of 4 seconds from malfunction detection. (In the case, however, when No. 1 cylinder top dead center has never been detected after the ignition switch is turned ON)
Detonation sensor	Fix the ignition timing with an allowance against detonation.
Alternator FR terminal	Prohibits alternator output suppression control against current consumers. (Operates as a normal alternator.)
Oil feeder control valve	Does not control variable valve timing. Cuts off fuel when the engine speed exceeds 5,000 r/min.
Throttle valve control servo	Stops electronic control throttle valve system to control engine output.
Throttle valve position feedback	Stops electronic control throttle valve system to control engine output.
Communication between throttle valve control microcomputer and engine control microcomputer	Treats as if the accelerator pedal depressed amount is approximately half of what it is when normal. Cuts off fuel when the engine speed exceeds 3,000 r/min.
Accelerator pedal position sensor (sub)	Detects accelerator pedal depressed amount using throttle position sensor (main) signals. Treats as if it is approximately half of what it is when normal. Cuts off fuel when the engine speed exceeds 3,000 r/min. Stops electronic control throttle valve system to control engine output if accelerator pedal position sensor (main) fails.