Lower Limit

LOWER LIMIT





Checking Mass Air Flow Sensor

- Ignition ON.
- Connect a voltmeter between Mass Air Flow (MAF) Sensor connector terminals 2 and 4.

The voltmeter should read 0.1 - 0.2 Volts.

If reading is OK:
- Proceed to test step below.

If reading is incorrect:
- Try a new mass air flow (MAF) sensor.





Checking for Air Leakage in the Exhaust System

- Check for air leakage in the Exhaust System.

Is there any air leakage?

No:
- Proceed to test step below.

Yes:
- Remedy as necessary.
- Continue by erasing diagnostic trouble code (DTC).





Checking the Fuel and Residual Pressure

- Check fuel and residual pressure, See FUEL DELIVERY AND AIR INDUCTION / FUEL PRESSURE.

Is the pressure OK?

Yes:
- Proceed to test step below.

No:
- Remedy as necessary.
- Continue by erasing diagnostic trouble code (DTC).

Checking Canister Purge Valve

- Remove hose to intake manifold from Canister Purge (CP) Valve. Reinstall hose after fault-tracing. When installing use pliers 981 4215 and a new hose clamp.
- Connect vacuum pump 999 5843 to canister purge (CP) valve connector.
- Pump up a vacuum.

The vacuum gauge should indicate a steady vacuum.

If reading is OK:
- Proceed to test step below.

If reading is incorrect:
- Try a new canister purge (CP) valve.
- Continue by erasing diagnostic trouble codes (DTCs) and resetting long-term fuel trim diagnostic trouble codes (DTCs)





Checking Engine Oil Level

- Check engine oil level.

The oil level should be between the MIN and MAX marks.

If reading is OK:
- Proceed to Checking Engine Oil section below.

If reading is incorrect:
- Proceed to test step below.

Fault-Tracing Information

- Ensure that the oil level is correct.

Then proceed to test step below.





Checking Engine Oil

- START the engine and idle it for a few minutes.
- Go into scrolling values list.
- Read off and note short-term fuel trim value.
- Disconnect and plug crankcase ventilation.
- Read off the short-term fuel trim value again.

This value should be more or less the same.

If reading is OK:
- Proceed to test step below.

If reading is incorrect:
- This indicates that the engine oil is contaminated with fuel.
- Change engine oil and oil filter.
- Then continue by erasing diagnostic trouble codes (DTCs) and resetting long-term fuel trim.





Connecting the Breakout Box

- Connect the breakout box and check ground terminals.
- Connect engine control module (ECM).
- Check all signals to and from engine control module (ECM).

Then proceed to test step below.





Verification

Hint: After carrying out the repair, check that the fault has been remedied as follows:

- Ignition OFF.
- Reconnect connectors and reinstall components.
- Go into scrolling value list.
Read off the long-term fuel trim value.
- Test drive the car
- Watch the long-term fuel trim value until it switches to completed.

If EFI-231 or EFI-232 is stored it should have the status intermittent fault.

Yes:
- Fault corrected

No:
- Proceed to test step below.

Fault-tracing information

- The verification result shows that the fault persists.
- Do you want to exit fault-tracing?

Yes:
- Fault not corrected

No:
- Return to Checking the Mass Air Flow Sensor section above.