When things go wrong your ECU stores "error codes" about the events it detected in its internal memory. Those remained stored as long as the ECU has power. The check engine light will display when an error occurs, but it won't remain on. So to check for which error codes are present in the ECU you have to put the car in test mode and then after you are all done, clear them so you can see if they reoccur.
Open the hood and locate the diagnostic connector. Is it next to the battery and can be seen in the figure to the right. You will want to connect terminals E1 and TE1. I used a big paper clip, which I leave in the back of my car, and it is actually 'sprung' against the connector lid to add some pressure for a better connection. Clicking on the picture will give you a much better view. It might be hard to see in the picture, so the bottom figure illustrates the terminals to connect, in red, with the paper clip.
After you do this start your car. The check engine light should now be blinking. If it is continuos quick blinking then you are fine there are no error codes, otherwise you have to count the blinks. Each set of blinks will represent one digit with a longer pause to separate digits. There may be more than one code present, but it is on a continuos loop. For example if you saw blink...blink.......blink...blink...blink...blink....... that would be a code 24. After you are done you can clear the codes by pulling the EFI fuse (15A) in the fuse block right next to the diagnostic connector for 30 seconds or more, make sure the engine is off.
| Code |
Error |
| 11 |
ECU(+B) |
| |
Diagnosis
-
- Momentary interruption in power supply
to ECU.
Trouble Area
-
- Ignition switch circuit
- Ignition switch
- Main relay circuit
- Main relay
- ECU
|
| 12 |
RPM Signal |
| |
Diagnosis
-
- No "NE" or "G" signal to ECU within 2 seconds after engine has been cranked.
Trouble Area
-
- Distributor, or CPS, circuit
- Distributor or CPS
- Starter signal circuit
- ECU
|
| 13 |
RPM Signal |
| |
Diagnosis
-
- No "NE" signal to ECU when engine speed is about 1,000 RPM.
Trouble Area
-
- Distributor, or CPS, circuit
- Distributor or CPS
- ECU
|
| 14 |
Ignition Signal |
| |
Diagnosis
-
- No "IGF" signal to ECU "A"
times in succession.
A = 6-8 (7M-GE)
A= 3 (7M-GTE)
Trouble Area
-
- Igniter and ignition coil circuit
- Igniter and ignition coil
- ECU
|
| 21 |
Oxygen Sensor Signal |
| |
Diagnosis
-
- Detection of oxygen sensor deterioration.
Trouble Area
-
- Oxygen sensor circuit
- Oxygen sensor
- ECU
|
| 22 |
Water Temp Sensor Signal |
| |
Diagnosis
-
- Open or short circuit in water temp sensor signal (THW).
Trouble Area
-
- Water temp sensor circuit
- Water temp sensor
- ECU
|
| 24 |
Intake air Temp Sensor Signal |
| |
Diagnosis
-
- Open or short circuit in intake air temp sensor signal (THA).
Trouble Area
-
- Intake air temp sensor circuit
- Intake air temp sensor
- ECU
|
| 25 |
Air-Fuel Ratio Lean Malfunction |
| |
Diagnosis
-
- When air-fuel ratio feedback compensation value or adaptive control value continues at the upper(lean) or lower(rich) limit renewed for a certain period of time.
- When air-fuel ration feedback compensation value or adaptive control value feedback frequency is abnormally high during feedback condition.
- When marked variation is detected in engine revolutions for each cylinder during idle switch on and feedback condition.
Trouble Area
-
- Injector circuit
- Injector
- Fuel line pressure
- Air flow meter
- Air intake system
- Oxygen sensor circuit
- Oxygen sensor
- Ignition system
- Water temp sensor
- ECU
|
| 26 |
Air-Fuel Ratio Rich Malfunction |
| |
Diagnosis
-
- When air-fuel ratio feedback compensation value or adaptive control value continues at the upper(lean) or lower(rich) limit renewed for a certain period of time.
- When air-fuel ration feedback compensation value or adaptive control value feedback frequency is abnormally high during feedback condition.
- When marked variation is detected in engine revolutions for each cylinder during idle switch on and feedback condition.
Trouble Area
-
- Injector circuit
- Injector
- Fuel line pressure
- Air flow meter
- Cold start injector
- Oxygen sensor circuit
- Oxygen sensor
- Water temp sensor
- ECU
-
|
| 27 |
Sub-Oxygen Sensor Signal or Sensor Heater |
| |
Diagnosis(Sub-Oxygen Sensor Signal)
-
- Open or short circuit in sub-oxygen sensor signal (OX2).
Trouble Area
-
- Sub-oxygen sensor circuit
- Sub-oxygen sensor
- ECU
|
| |
Diagnosis(Sub-Oxygen Sensor Heater)
-
- Open or short circuit in sub-oxygen sensor heater (HT).
Trouble Area
-
- Sub-oxygen sensor heater circuit
- Sub-oxygen sensor heater
- ECU
|
| 31 |
Air Flow Meter Signal |
| |
Diagnosis
-
- (7M-GE) Open circuit in VC signal or short circuit between VS and E2 when idle contacts are closed.
- (7M-GTE) Open or short circuit in air flow meter signal.
Trouble Area
-
- Air flow meter circuit
- Air flow meter
- ECU
|
| 32 |
Air Flow Meter Signal(7M-GE)
HAC Sensor Signal(7M-GTE)
|
| |
Diagnosis(Air Flow Meter Signal(7M-GE))
-
- Open circuit in E2 or short circuit between VC and VS.
Trouble Area
-
- Air flow meter circuit
- Air flow meter
- ECU
|
| |
Diagnosis(HAC Sensor Signal(7M-GTE))
-
- Open circuit or short circuit in HAC sensor signal.
Trouble Area
-
|
| 34 |
Turbocharger Pressure |
| |
Diagnosis
-
- The turbocharger pressure is abnormal.
Trouble Area
-
- Turbocharger
- Air flow meter
- ECU
- Intercooler system
|
| 41 |
Throttle Position Sensor Signal |
| |
Diagnosis
-
- Open or short circuit in throttle position sensor signal.
Trouble Area
-
- Throttle position sensor circuit
- Throttle position sensor
- ECU
|
| 42 |
Vehicle Speed Sensor Signal |
| |
Diagnosis
-
- No "SPD" signal to ECU for 8 seconds when engine speed is between 2,500RPM and 4,500RPM (7M-GE) or 4,000RPM (7M-GTE) and coolant temp is below 80°C(176°F) and neutral start switch is off.
Trouble Area
-
- Vehicle speed sensor circuit
- Vehicle speed sensor
- ECU
|
| 43 |
Starter Signal |
| |
Diagnosis
-
- No "STA" signal to ECU until engine speed reaches 800RPM with vehicle not moving.
Trouble Area
-
- Ignition switch circuit.
- Ignition switch
- ECU
|
| 51 |
Switch Signal |
| |
Diagnosis
-
- No "IDL" signal, "NSW" signal or "A/C" signal to ECU, during diagnosis check.
Trouble Area
-
- A/C switch circuit
- A/C switch
- A/C amplifier
- Throttle position sensor circuit
- Throttle position sensor
- ECU
|
| 52 |
Knock Sensor Signal |
| |
Diagnosis
-
- Open or short circuit in knock sensor signal.
Trouble Area
-
- Knock sensor circuit
- Knock sensor
- ECU
|
| 53 |
Knock Control Signal in ECU |
| |
Diagnosis
-
- Knock control program faulty.
Trouble Area
-
|
| 71 |
EGR System Malfunction |
| |
Diagnosis
-
- EGR gas temp below predetermined level during EGR operation.
- Open circuit in EGR gas temp sensor signal (THG).
Trouble Area
-
- EGR system (EGR valve, EGR hose etc.)
- EGR gas temp sensor circuit
- EGR gas temp sensor
- VSV for EGR circuit
- VSV for EGR
- ECU
|
