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 is illuminated. 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. There are two methods for checking the indicator lamp burn out: When the ignition switch is in ON position, the indicator lamp is illuminated, and then extinguished few seconds later. When the ignition switch is in ON position and the engine starts, the indicator lamp is extinguished.

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
P0038	Oxygen sensor (rear) heater circuit high input
P0097^*1	No. 2 intake air temperature sensor circuit low input
P0098^*1	No. 2 intake air temperature sensor circuit high input
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	No. 1 intake air temperature sensor circuit low input
P0113^*1	No. 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
P0122^*1	Throttle position sensor (main) circuit low input
P0123^*1	Throttle position sensor (main) circuit high input
P0125^*1	Insufficient coolant temperature for closed loop fuel control
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
P0138	Oxygen sensor (rear) circuit high voltage
P0171	Abnormal fuel system (lean)
P0172	Abnormal fuel system (rich)
P0201	No. 1 injector system
P0202	No. 2 injector system
P0203	No. 3 injector system
P0204	No. 4 injector system
P0222^*1	Throttle position sensor (sub) circuit low input
P0223^*1	Throttle position sensor (sub) circuit high input
P0243	Waste gate solenoid valve system
P0300^*2	Random/multiple cylinder misfire detected
P0301^*2	No. 1 cylinder misfire detected
P0302^*2	No. 2 cylinder misfire detected
P0303^*2	No. 3 cylinder misfire detected
P0304^*2	No. 4 cylinder misfire detected
P0327	Detonation sensor circuit low input
P0328	Detonation sensor circuit high input
P0335^*1	Crank angle sensor system
P0340^*1	Inlet camshaft position sensor system
P0365^*1	Exhaust camshaft position sensor system
P0420	Catalyst malfunction
P0443	Purge control solenoid valve system
P0500^*1	Vehicle speed signal system
P0603^*1	EEPROM malfunction
P0606^*1	Engine-ECU main processor 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
P1021	Inlet oil feeder control valve system
P1025	Exhaust oil feeder control valve system
P1233^*1	Trustful check throttle position sensor (main)
P1234^*1	Trustful check throttle position sensor (sub)
P1235^*1	Trustful check air flow sensor
P1236^*1	A/D converter
P1237^*1	Trustful check accelerator pedal position sensor
P1238^*1	Air flow sensor trustful for torque monitoring
P1239^*1	Trustful check engine speed
P1241^*1	Torque monitoring
P1590^*1	TC-SST-ECU to engine-ECU communication error in torque reduction request
P1603^*1	Battery backup circuit malfunction
P1676^*1	Variant coding system
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
U0101^*1	TC-SST-ECU time-out
U0121^*1	ASC-ECU time-out
U0141^*1	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 "*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 is illuminated at the time.
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.

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.

FREEZE FRAME DATA

When the engine-ECU detects a malfunction and stores 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	****
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	%

note

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

note

^*2: The items of Freeze Frame Data can be seen by selecting "Freeze Frame Data (OBD)" on "Self-diagnosis" screen of M.U.T.-III. When system malfunctions are detected, the first detected malfunction data only is stored.

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

List of fail-safe and backup function items

Code No.	Diagnosis item	Control content during malfunction
P0097	No. 2 intake air temperature sensor circuit low input	Control as if the intake air temperature in the inlet manifold is 25°C.
P0098	No. 2 intake air temperature sensor circuit high input	Control as if the intake air temperature in the inlet manifold is 25°C.
P0112	No. 1 intake air temperature sensor circuit low input	Control as if the intake air temperature is 25°C.
P0113	No. 1 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.
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.
P0125	Insufficient coolant temperature for closed loop fuel control	Control as if the engine coolant temperature is 80°C.
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.
P0234	Waste gate system malfunction	Fuel is cut in abnormal engine overboost condition.
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	Inlet camshaft position sensor system	Engine runs in learned pattern until engine stops. Does not control variable valve timing (V.V.T.).
P0365	Exhaust camshaft position sensor system	Does not control variable valve timing (V.V.T.).
P0513	Immobilizer malfunction	Engine start is prohibited.
P0606	Engine-ECU main processor malfunction	Throttle opening degree position is in default position.
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.
P1021	Inlet oil feeder control valve system	V.V.T. phase angle (inlet) becomes most retarded angle.
P1025	Exhaust oil feeder control valve system	V.V.T. phase angle (exhaust) becomes most advanced angle.
P1231	Trustful check active stability control (ASC)	Torque requested by active stability control (ASC) is ignored.
P1232	Fail-safe control system	Microcomputer is reset.
P1233	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.
P1234	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.
P1235	Trustful check air flow sensor	Fuel control is carried out using throttle opening degree and engine speed in accordance with preset map.
P1236	A/D converter	Throttle opening degree position is in default position.
P1237	Trustful check accelerator pedal position sensor	Throttle opening degree position is in default position.
P1238	Air flow sensor trustful for torque monitoring	Throttle opening degree position is in default position.
P1239	Trustful check engine speed	Throttle opening degree position is in default position.
P1240	Trustful check ignition angle	Ignition retard is not carried out
P1241	Torque monitoring	Throttle opening degree position is in default position.
P1242	Fail safe control monitoring	Throttle opening degree position is in default position.
P1243	Inquiry/response error	Microcomputer is reset.
P1244	RAM test for all area	Microcomputer is reset.
P1245	Cyclic RAM test (engine)	Microcomputer is reset.
P1247	Trustful check TC-SST	Torque requested by TC-SST-ECU is ignored.
P1590	TC-SST-ECU to engine-ECU communication error in torque reduction request	Engine output is restricted.
P1603	Battery backup circuit malfunction	All diagnosis codes are stored once failure judgment 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) range/performance problem	Throttle opening degree position is in default position.
P2138	Accelerator pedal position sensor (main and sub) range/performance problem	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	KOS-ECU <Vehicles with KOS> or WCM <Vehicles with WCM> communication error	Engine start is prohibited.