Upper Limit

UPPER LIMIT





Checking Mass Air Flow Sensor

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

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 Intake System

- Check for air leakage in the Intake System.

Is there any air leakage?

No:
- Proceed to test step below.

Yes:
- Remedy as necessary.
- Then continue with erase diagnostic trouble code (DTC) diagnostic trouble code (DTC) reset adaptation.





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.
- Then continue with erase diagnostic trouble code (DTC) diagnostic trouble code (DTC) reset adaptation.





Checking the Fuel and Residual Pressure

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

Is fuel pressure OK?

Yes:
- Proceed to test step below.

No:
- Remedy as necessary.
- Then continue with: Erasing diagnostic trouble codes (DTCs) and resefling adaption





Checking Pulsation Damper

- Test drive the car
- Go into scrolling value list.
- Read off short-term fuel trim and engine speed (RPM) values.
- Drive the car on a flat road.
- Maintain engine speed at 1,250 rpm.
- Watch short-term fuel trim

The value should oscillate around 1.000.

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

If reading is incorrect:
- Try a new pulsation damper.
- Then proceed to Verification section below.





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).
- Remedy as necessary.

Then proceed to Verification section 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: intermiflent 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 Mass Air Flow Sensor section above.