DIAGNOSIS FUNCTION

ENGINE WARNING LAMP (CHECK ENGINE LAMP)

When the abnormal condition occurs with respect to the items of Multipoint Fuel Injection (MPI) system shown in the table, the engine warning lamp will illuminate or flash. When the lamp remains illuminated after the engine start, or when the lamp is illuminated while the engine is running, check the diagnosis code output. When the engine warning lamp-related circuit is normal, the engine warning lamp will illuminate as a bulb check by turning on the ignition switch and then go out after the engine starts.

ENGINE WARNING LAMP INSPECTION ITEMS

caution

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

P0031	Oxygen sensor (front) heater circuit low input
P0032	Oxygen sensor (front) heater circuit high input
P0037	Oxygen sensor (rear) heater circuit low input <EURO4>
P0038	Oxygen sensor (rear) heater circuit high input <EURO4>
P0068^*1	Trustful check air flow sensor
P0102^*1	Air flow sensor circuit low input
P0103^*1	Air flow sensor circuit high input
P0107	Manifold absolute pressure sensor circuit low input
P0108	Manifold absolute pressure sensor circuit high input
P0112^*1	Intake air temperature sensor circuit low input
P0113^*1	Intake air temperature sensor circuit high input
P0117^*1	Engine coolant temperature sensor circuit low input
P0118^*1	Engine coolant temperature sensor circuit high input
P0121^*1	Trustful check throttle position sensor (main)
P0122^*1	Throttle position sensor (main) circuit low input
P0123^*1	Throttle position sensor (main) circuit high input
P0131	Oxygen sensor (front) circuit low voltage
P0132	Oxygen sensor (front) circuit high voltage
P0133	Oxygen sensor (front) circuit slow response
P0134^*1	Oxygen sensor (front) circuit no activity detected
P0137	Oxygen sensor (rear) circuit low voltage <EURO4>
P0138	Oxygen sensor (rear) circuit high voltage <EURO4>
P0171	Abnormal fuel system (lean)
P0172	Abnormal fuel system (rich)
P0221^*1	Trustful check throttle position sensor (sub)
P0222^*1	Throttle position sensor (sub) circuit low input
P0223^*1	Throttle position sensor (sub) circuit high input
P0261	No. 1 injector circuit low input
P0262	No. 1 injector circuit high input
P0264	No. 2 injector circuit low input
P0265	No. 2 injector circuit high input
P0267	No. 3 injector circuit low input
P0268	No. 3 injector circuit high input
P0270	No. 4 injector circuit low input
P0271	No. 4 injector circuit high input
P0300^*2	Random/multiple cylinder misfire detected <EURO4>
P0301^*2	No. 1 cylinder misfire detected <EURO4>
P0302^*2	No. 2 cylinder misfire detected <EURO4>
P0303^*2	No. 3 cylinder misfire detected <EURO4>
P0304^*2	No. 4 cylinder misfire detected <EURO4>
P0335^*1	Crank angle sensor system
P0340^*1	Camshaft position sensor system
P0350	Ignition coil primary circuit malfunction <EURO2>
P0421	Catalyst malfunction <EURO4>
P0458	Purge control solenoid valve circuit low input
P0459	Purge control solenoid valve circuit high input
P0500^*1	Vehicle speed sensor system <Vehicles without ABS/ASTC> Vehicle speed signal system <Vehicles with ABS/ASTC>
P0602^*1	Variant coding system
P0606^*1	Engine-ECU main processor malfunction
P060B^*1	A/D converter
P060D^*1	Trustful check accelerator pedal position sensor
P061A^*1	Torque monitoring
P062F^*1	EEPROM malfunction
P0630^*1	Chassis number not programmed
P0638^*1	Throttle valve control servo circuit range/performance problem
P0642^*1	Throttle position sensor power supply
P0657^*1	Throttle valve control servo relay circuit malfunction
P1238^*1	Air flow sensor trustful for torque monitoring
P1603^*1	Battery backup circuit malfunction
P2100^*1	Throttle valve control servo circuit (open)
P2101^*1	Throttle valve control servo magneto malfunction
P2122^*1	Accelerator pedal position sensor (main) circuit low input
P2123^*1	Accelerator pedal position sensor (main) circuit high input
P2127^*1	Accelerator pedal position sensor (sub) circuit low input
P2128^*1	Accelerator pedal position sensor (sub) circuit high input
P2135^*1	Throttle position sensor (main and sub) range/performance problem
P2138^*1	Accelerator pedal position sensor (main and sub) range/performance problem
P2228^*1	Barometric pressure sensor circuit low input
P2229^*1	Barometric pressure sensor circuit high input
P2252	Oxygen sensor offset circuit low voltage
P2253	Oxygen sensor offset circuit high voltage
U0121^*1	ABS-ECU/ASTC time-out <Vehicles with ABS/ASTC>

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 "^*1" in the diagnosis code number column, the engine warning lamp illuminates only on the first detection of the malfunction.

note

The codes marked with a "^*2" in the diagnosis code number column have the following two conditions for illuminating the engine warning lamp.

In case that the misfire causing the damaged catalyst is detected, the engine warning lamp will flash until the condition is corrected. If the system detects the same malfunction after the next engine start, and then the condition is corrected, the engine warning lamp will illuminate.
In case that the misfire deteriorating the exhaust gas is detected, the engine warning lamp is illuminated when the same malfunction is redetected after the next engine start.

note

Even if the malfunction is not detected when the engine-ECU monitors the malfunction three consecutive times* after the engine warning lamp illuminates, turn off the engine warning lamp when the engine starts next time.
*: In this case, "one time" in monitoring the malfunction means the period from the time of the current engine start to the time of the next engine start. "one time" in monitoring the misfire or the fuel system malfunction means the time when the operating conditions (such as the engine speed or the engine coolant temperature) becomes similar operating conditions of the first detected malfunction.

METHOD OF READING AND ERASING DIAGNOSIS CODES

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

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

Reading data list 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 data list 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 data list 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.

PROVISIONAL DIAGNOSIS CODE CONFIRMED

If detecting the malfunction during the first drive cycle, the engine-ECU temporarily sets the diagnosis code as the provisional diagnosis code. If detecting the same malfunction during the next drive cycle, the engine-ECU determines that the malfunction exists. The engine-ECU sets the diagnosis code. On the M.U.T.-III, it is possible to display the set provisional diagnosis code which the engine-ECU had detected during the first drive cycle. This makes it possible to confirm in one drive cycle whether the malfunction could happen again after the repair.

CONFIRMATION METHOD

After the ignition switch is in "LOCK" (OFF) position, connect the M.U.T.-III to the diagnosis connector.
Turn the ignition switch to the "ON" position.
Select "MPI/GDI/DIESEL" from System Select Screen of the M.U.T.-III.
Select "Special Function" from MPI/GDI/DIESEL Screen.
Select "Provisional DTCs" from Special Function Screen.

FREEZE FRAME DATA

When the engine-ECU detects a malfunction and sets a diagnosis code, it also stores a current status of the engine. This function is called "Freeze frame data". By analysing this "Freeze frame" data with the M.U.T.-III, an effective troubleshooting can be performed.

The display items of freeze frame data are shown below.

FREEZE FRAME DATA

DISPLAY ITEM LIST

Item No.	Date Item	Unit·Condition
1	Odometer	km
2	Ignition cycle (Warm up cycle)	-
4	Accumulated minute^*1	min
AA^*2	Air flow sensor	g/s
AB^*2	Throttle position sensor (main)	%
BB^*2	Barometric pressure sensor	kPa
BC^*2	Relative throttle position sensor	%
BD^*2	Throttle position sensor (sub)	%
BE^*2	Accelerator pedal position sensor (main)	%
BF^*2	Accelerator pedal position sensor (sub)	%
C0^*2	Fuel system status 1	CL (closed loop)^3 OL (open loop)^4 OL: DRV (condition of open loop due to acceleration and deceleration driving) OL: SYS (condition of open loop due to system failure) CL: HO2S (condition of closed loop only using front oxygen sensor when rear oxygen sensor is failed)
C1^2^5	Fuel system status 2	N/A
C2^*2	Calculated load valve	%
C3^*2	Engine coolant temperature sensor	°C
C4^*2	Short term fuel trim 1	%
C5^2^5	Short term fuel trim 3	****
C6^*2	Long term fuel trim 1	%
C7^2^5	Long term fuel trim 3	****
C8^2^5	Short term fuel trim 2	****
CA^2^5	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^*6	sec
D6^*2	Purge solenoid duty	%
D8^*2	Power supply voltage	V
D9^*2	Absolute load value	%
DA^*2	Target equivalence ratio	-
DB^*2	Intake air temperature sensor	°C
DC^*2	Commanded throttle actuator control	%
DD^*2	Relative accelerator pedal position sensor	%

note

^*1: Accumulated time of current malfunction from time point when malfunction is detected.

note

*2: The items can be seen by selecting "Freeze Frame Data (OBD)" on Self-diagnosis Screen of M.U.T.-III. If detecting multiple malfunctions, the engine-ECU stores the data for only the first item that was detected. If detecting the misfire or fuel system malfunction, the engine-ECU stores the data by giving priority to the misfire or fuel system malfunction in spite of the chronological order of the detected malfunction. NOTE: The Freeze Frame Data (OBD) should not be stored for the diagnosis code when the engine warning lamp does not illuminate.

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: Data items are displayed on M.U.T.-III display, but the in-line 4 engine is not applicable and its data is displayed as "N/A" or "****".

note

^*6: Time between engine start and malfunction detection.

FAIL-SAFE AND BACKUP FUNCTION

The control is carried out, which keeps the safety driving by the preset control logic when the diagnosis code is set. The diagnosis code having the fail-safe function is as follows.

List of fail-safe and backup function items

Code No.	Diagnosis item	Control content during malfunction
P0068	Trustful check air flow sensor	Fuel control is carried out using throttle opening degree and engine speed in accordance with preset map.
P0102	Air flow sensor circuit low input	Fuel control is carried out using throttle opening degree and engine speed in accordance with preset map.
P0103	Air flow sensor circuit high input	Fuel control is carried out using throttle opening degree and engine speed in accordance with preset map.
P0107	Manifold absolute pressure sensor circuit low input	Control as if the inlet manifold vacuum pressure is 101 kPa.
P0108	Manifold absolute pressure sensor circuit high input	Control as if the inlet manifold vacuum pressure is 101 kPa.
P0112	Intake air temperature sensor circuit low input	Control as if the intake air temperature is 25°C.
P0113	Intake air temperature sensor circuit high input	Control as if the intake air temperature is 25°C.
P0117	Engine coolant temperature sensor circuit low input	Control as if the engine coolant temperature is 80°C.
P0118	Engine coolant temperature sensor circuit high input	Control as if the engine coolant temperature is 80°C.
P0121	Trustful check throttle position sensor (main)	Throttle opening degree is restricted. Throttle opening degree position is in default position if throttle position sensor (sub) fails.
P0122	Throttle position sensor (main) circuit low input	Throttle opening degree is restricted. Throttle opening degree position is in default position if throttle position sensor (sub) fails.
P0123	Throttle position sensor (main) circuit high input	Throttle opening degree is restricted. Throttle opening degree position is in default position if throttle position sensor (sub) fails.
P0221	Trustful check throttle position sensor (sub)	Throttle opening degree is restricted. Throttle opening degree position is in default position if throttle position sensor (main) fails.
P0222	Throttle position sensor (sub) circuit low input	Throttle opening degree is restricted. Throttle opening degree position is in default position if throttle position sensor (main) fails.
P0223	Throttle position sensor (sub) circuit high input	Throttle opening degree is restricted. Throttle opening degree position is in default position if throttle position sensor (main) fails.
P0300	Random/multiple cylinder misfire detected	The supply of fuel to the misfiring cylinder can possibly be cut.
P0301	No. 1 cylinder misfire detected	The supply of fuel to the misfiring cylinder can possibly be cut.
P0302	No. 2 cylinder misfire detected	The supply of fuel to the misfiring cylinder can possibly be cut.
P0303	No. 3 cylinder misfire detected	The supply of fuel to the misfiring cylinder can possibly be cut.
P0304	No. 4 cylinder misfire detected	The supply of fuel to the misfiring cylinder can possibly be cut.
P0327	Detonation sensor circuit low input	Fix the ignition timing with an allowance against detonation.
P0328	Detonation sensor circuit high input	Fix the ignition timing with an allowance against detonation.
P0340	Camshaft position sensor system	Engine runs in learned pattern until engine stops.
P0350	Ignition coil primary circuit malfunction	Fuel is cut for cylinder with ignition coil malfunction.
P0513	Immobilizer system	Engine start is prohibited.
P0537	Fin thermo sensor circuit low input	Control as if the evaporator surface temperature is -6.4°C.
P0538	Fin thermo sensor circuit high input	Control as if the evaporator surface temperature is -6.4°C.
P0604	RAM error	Microcomputer is reset. or Throttle opening degree position is in default position.
P0606	Engine-ECU main processor malfunction	Throttle opening degree position is in default position.
P060B	A/D converter	Throttle opening degree position is in default position.
P060D	Trustful check accelerator pedal position sensor	Throttle opening degree position is in default position.
P061A	Torque monitoring	Throttle opening degree position is in default position.
P061F	Fail-safe control system	Microcomputer is reset.
P0622	Alternator FR terminal system	Prohibits alternator output suppression control against current consumers. (operates as a normal alternator.)
P0638	Throttle valve control servo circuit range/performance problem	Throttle opening degree position is in default position.
P0642	Throttle position sensor power supply	Throttle opening degree position is in default position.
P0657	Throttle valve control servo relay circuit malfunction	Throttle opening degree position is in default position.
P1231	Trustful check active stability & traction control (ASTC)	Torque requested by active stability & traction control (ASTC) is ignored.
P1238	Manifold absolute pressure sensor trustful for torque monitoring	Throttle opening degree position is in default position.
P1240	Trustful check ignition angle	Ignition retard is not carried out.
P1242	Fail safe control monitoring	Throttle opening degree position is in default position.
P1243	Inquiry/response error	Microcomputer is reset.
P1603	Battery backup circuit malfunction	All diagnosis codes are set once failure judgement is completed.
P2100	Throttle valve control servo circuit (open)	Throttle opening degree position is in default position.
P2101	Throttle valve control servo magneto malfunction	Throttle opening degree position is in default position.
P2122	Accelerator pedal position sensor (main) circuit low input	Throttle opening degree is restricted. Throttle opening degree position is in default position if accelerator pedal position sensor (sub) fails.
P2123	Accelerator pedal position sensor (main) circuit high input	Throttle opening degree is restricted. Throttle opening degree position is in default position if accelerator pedal position sensor (sub) fails.
P2127	Accelerator pedal position sensor (sub) circuit low input	Throttle opening degree is restricted. Throttle opening degree position is in default position if accelerator pedal position sensor (main) fails.
P2128	Accelerator pedal position sensor (sub) circuit high input	Throttle opening degree is restricted. Throttle opening degree position is in default position if accelerator pedal position sensor (main) fails.
P2135	Throttle position sensor (main and sub) circuit range/performance problem	Throttle opening degree position is in default position.
P2138	Accelerator pedal position sensor (main and sub) circuit range/performance	Throttle opening degree is restricted. Throttle opening degree position is in default position if accelerator pedal position sensor (sub) fails.
P2228	Barometric pressure sensor circuit low input	Control as if the barometric pressure is 101 kPa.
P2229	Barometric pressure sensor circuit high input	Control as if the barometric pressure is 101 kPa.
P2253	Oxygen sensor offset circuit high voltage	Does not control air-fuel ratio closed loop.
U0167	Immobilizer communication error	Engine start is prohibited.
U0415	ASTC-ECU CAN data abnormality	Torque requested by active stability & traction control (ASTC) is ignored.