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.
Code No.
Diagnosis item
-
Engine-A/T-ECU
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
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
P0130
Right bank oxygen sensor (front) circuit
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*1
Right bank oxygen sensor (front) circuit no activity detected
P0135
Right bank oxygen sensor (front) heater system
P0136
Right bank oxygen sensor (rear) circuit
P0137
Right bank oxygen sensor (rear) circuit low voltage
P0138
Right bank oxygen sensor (rear) circuit high voltage
P0141
Right bank oxygen sensor (rear) heater system
P0150
Left bank oxygen sensor (front) circuit
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*1
Left bank oxygen sensor (front) circuit no activity detected
P0155
Left bank oxygen sensor (front) heater system
P0156
Left bank oxygen sensor (rear) circuit
P0157
Left bank oxygen sensor (rear) circuit low voltage
P0158
Left bank oxygen sensor (rear) circuit high voltage
P0161
Left bank oxygen sensor (rear) heater system
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*1
Throttle position sensor (sub) circuit low input
P0223*1
Throttle position sensor (sub) circuit high input
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
P0305*2
No. 5 cylinder misfire detected
P0306*2
No. 6 cylinder misfire detected
P0335*1
Crank angle sensor system
P0340*1
Camshaft position sensor system
P0403
Exhaust gas recirculation control system
P0421
Warm Up Catalyst Malfunction (right bank)
P0431
Warm Up Catalyst Malfunction (left bank)
P0443
Purge control solenoid valve system
P0500*1
Vehicle speed sensor system
P0603*1
EEPROM malfunction
P0606*1
Engine-A/T-ECU main processor malfunction
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
Oil feeder control valve system
P1602*1
Communication malfunction (between engine-A/T-ECU main processor and system LSI)
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
U1108*1
Combination meter timeout
note After the engine-A/T-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 - How to Cope with Intermittent Malfunctions.

DIAGNOSIS USING DIAGNOSIS 2 MODE



  1. Switch the diagnosis mode of the engine control unit to DIAGNOSIS 2 mode using the M.U.T.-III.
  2. Carry out a road test.
  3. Take a reading of the diagnosis code and repair the problem location.
  4. Turn the ignition switch to OFF and then back to ON again.
    note By turning the ignition switch to OFF, the engine-A/T-ECU will switch the diagnosis mode from DIAGNOSIS 2 mode to DIAGNOSIS 1 mode.
  5. Erase the diagnosis codes.

INSPECTION USING M.U.T.-III DATA LIST AND ACTUATOR TESTING


1.Carry out inspection by means of the data list and the actuator test function, if there is an abnormality, check and repair the chassis harness and components.
2.After repairing, re-check using the M.U.T.-III and check that the abnormal input and output have returned to normal as a result of the repairs.
3.Erase the diagnosis code memory.
4.Remove the M.U.T.-III, and then start the engine again and carry out a road test to confirm that the problem has disappeared.

FREEZE FRAME DATA


When the engine-A/T-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 analyzing 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.


DISPLAY ITEM LIST
Item No.
Data
Unit/Condition
AA
Air flow sensor
g/s
AB
TPS (main)
%
BA
Target EGR
%
BB
Barometric pressure sensor
kPa
BC
Relative TPS
%
BD
TPS (sub)
%
BE
APS (main)
%
BF
APS (sub)
%
C0
Fuel system status 1

  • CL (closed loop)*1
  • OL (open loop)*2
  • OL: DRV (open loop-drive condition)*3
  • OL: SYS (open loop-system failure)*4
  • CL: HO2S (closed loop-system failure)*5

C1
Fuel system status 2

  • CL (closed loop)*1
  • OL (open loop)*2
  • OL: DRV (open loop-drive condition)*3
  • OL: SYS (open loop-system failure)*4
  • CL: HO2S (closed loop-system failure)*5

C2
Calculated load value
%
C3
Engine coolant TEMP.sensor
°C
C4
Short term fuel trim 1
%
C5*6
Short term fuel trim 3
%
C6
Long term fuel trim 1
%
C7*6
Long term fuel trim 3
%
C8
Short term fuel trim 2
%
C9*6
Short term fuel trim 4
%
CA
Long term fuel trim 2
%
CB*6
Long term fuel trim 4
%
CC
Manifold absolute pressure sensor
kPa
CD
Crank angle sensor
rpm
CE
Vehicle speed signal
km/h
CF
Advance ignition
deg
D0
Intake air temperature sensor
°C
D1
Time since engine running*7
sec
D6
EVAP. emission purge SoL duty
%
D8
Power supply voltage
V
D9
Absolute load value
%
DA
Target equivalence ratio
-
DB
Intake air temperature sensor (ambient temperature)
°C
DC
Throttle actuator
%
note *1: Condition in which oxygen sensor signals are fed back to the engine-A/T-ECU for controlling fuel.
note *2: Condition in which fuel is controlled without oxygen sensor signals being fed back to the engine-A/T-ECU because the condition to shift to the closed loop is not met.
note *3: Condition of open loop due to acceleration and deceleration driving.
note *4: Condition of open loop due to system failure.
note *5: Condition of closed loop due to system failure.
note *6: Data items are displayed on M.U.T.-III display, but the 6 cylinders engine is not applicable and its data is displayed as "**".
note *7: Time between engine start and malfunction detection.

FAIL-SAFE FUNCTION REFERENCE TABLE



Malfunctioning item
Control contents 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).
  • Does not control idle speed.

Intake air temperature sensor
Controls as if the intake air temperature is 25°C.
Barometric pressure sensor
Controls as if the barometric pressure is 101 kPa.
Engine coolant temperature sensor
Controls as if the engine coolant temperature is 80°C. (This control will be continued until the ignition switch is turned to the "LOCK" (OFF) position even though the sensor signal returns to normal.)
Camshaft position sensor

  • The control condition before the fail is determined is continued.
  • After 4 seconds pass from when the malfunction is detected, the fuel is shut off. (After the ignition switch is turned to ON position, the No.1 cylinder top dead center is no detected at all.)

Right bank oxygen sensor (front)
Does not control air-fuel ratio closed loop.
Right bank oxygen sensor (rear)
Controls air-fuel ratio closed loop using only right bank oxygen sensor (front) signals.
Left bank oxygen sensor (front)
Does not control air-fuel ratio closed loop.
Left bank oxygen sensor (rear)
Controls air-fuel ratio closed loop using only left bank oxygen sensor (front) signals.
Manifold absolute pressure sensor

  • Does not correct the injector drive time corresponding to inlet manifold vacuum pressure.
  • Does not control exhaust gas recirculation.

Throttle position sensor (main)

  • Controls the throttle valve position through the use of the throttle position sensor (sub) signal.
  • Renders the amount of accelerator pedal travel as being approximately one-half the normal opening angle.
  • Prohibits the operation of the engine speed feedback control.
  • Cuts off fuel when the engine speed exceeds 3,000 r/min.
  • Suppresses the engine output by stopping the electronic-controlled throttle valve system if the throttle position sensor (sub) is also malfunctioning.

Accelerator pedal position sensor (main)

  • Detects the amount of the accelerator pedal travel through the use of the accelerator pedal position sensor (sub) signal, but rendering it only as being approximately one-half the normal opening angle.
  • Cuts off fuel when the engine speed exceeds 3,000 r/min.
  • Suppresses the engine output by stopping the electronic-controlled throttle valve system if the accelerator pedal position sensor (sub) is also malfunctioning.

Throttle position sensor (sub)

  • Controls the throttle valve position through the use of the throttle position sensor (main) signal.
  • Renders the amount of accelerator pedal travel as being approximately one-half the normal opening angle.
  • Cuts off fuel when the engine speed exceeds 3,000 r/min.
  • Suppresses the engine output by stopping the electronic-controlled throttle valve system if the throttle position sensor (main) is also malfunctioning.

Accelerator pedal position sensor (sub)

  • Detects the amount of the accelerator pedal travel through the use of the accelerator pedal position sensor (main) signal, but rendering it only as being approximately one-half the normal opening angle.
  • Cuts off fuel when the engine speed exceeds 3,000 r/min.
  • Suppresses the engine output by stopping the electronic-controlled throttle valve system if the accelerator pedal position sensor (main) is also malfunctioning.

Throttle valve control microcomputer

  • Suppresses the engine output by stopping the electronic-controlled throttle valve system.
  • Prohibits the operation of the engine speed feedback control.

Oil feeder control valve

  • Do not switch to high-speed cam.
  • Cut off fuel when the engine speed exceeds 5,000 r/min.

Throttle valve control servo

  • Suppresses the engine output by stopping the electronic-controlled throttle valve system.
  • Prohibits the operation of the engine speed feedback control.

Throttle valve position feedback

  • Suppresses the engine output by stopping the electronic-controlled throttle valve system.
  • Prohibits the operation of the engine speed feedback control.

Communication between throttle valve control microcomputer and engine control microcomputer

  • Renders the amount of accelerator pedal travel as being approximately one-half the normal opening angle.
  • Prohibits the operation of the engine speed feedback control.
  • Cuts off fuel when the engine speed exceeds 3,000 r/min.

Detonation sensor
The ignition timing is set having enough time against knocking.
Ignition coil, power transistor
Shuts off fuel injection to misfiring cylinders.
Alternator FR terminal
Does not control the output of the alternator according to an electrical load. (works as a normal alternator)