P0108

DTC's P0105, P0106, P0107, P0108:

DIAGNOSTIC TROUBLE CODES PO1O5, PO1O6, PO1O7, PO1O8
MANIFOLD ABSOLUTE PRESSURE SENSOR, MALFUNCTIONING OR NOT WORKING AT ALL

Fault symptoms
The malfunction indicator lamp is on. Deterioration in driveablity, basic charging pressure. Any other diagnostic trouble codes (oxygen sensor, adaptation).
AC compressor not working. Pressure gauge displays implausible values.

Conditions.
^ In case of short circuit/open circuit, diagnostic trouble code appears after 2 seconds.
^ In case of an implausible pressure value, diagnostic trouble code appears after 2 minutes.
^ If the hose has been disconnected, diagnostic trouble code appears when fuel shut-off occurs during engine braking.

Diagnostic procedure
1. Use the ISAT and the turbo pressure gauge in the main instrument to check pressure sensor operation.

- Ignition switched ON.
- Connect ISAT and select the "INTAKE PRESSURE" command on the "READ FUNCTIONS" menu.
- If pressure sensor function is OK, the ISAT must display approx. 102 kPa (N.B. the value depends on air pressure) and the turbo/APC needle must be in the area between the white and orange sections of the turbo pressure gauge.
- If the measured value is incorrect, continue with step 3.
- If the measured value is correct, continue with step 2.

2. Checking of pressure sensor function continues. Start the engine and run it at idling speed. If pressure function is OK, the ISAT must display approx. 40-60 kPa and the turbo/APC needle must be in the middle of the white section of the turbo pressure gauge.

- If the measured value is faulty, check and if necessary replace the vacuum hose between the pressure sensor and the intake manifold.
- If the fault persists, replace the pressure sensor.
- If the measured value is correct, continue with step 4.

DTC's P0105, P0106, P0107, P0108:

3. Check the electrical interface in the pressure sensor connector.

- Disconnect the 3-pole connector. Measure the voltage in the female connector.
^ Pin 3 to Batt - _________ approx. 5 V.
^ Pin 2 to Batt - _________ approx. 5 V.
^ Batt + to pin 1 _________ approx. 12 V.
- Carry out current measurement (mA) in:
^ Pin 2 to pin 1 ______ approx. 0.1 mA.
- The measurements above are to show whether ECM including wiring as far as the pressure sensor are operating correctly.
- If all the measured values are correct, continue with step 4.
- If any measured value is incorrect, continue with step 5.

DTC's P0105, P0106, P0107, P0108:

4. Check pressure sensor function using pressure gauge and a pressure/vacuum pump.

- Generate a positive pressure of 0.6 bar and a negative pressure of -0.6 bar.

The ISAT must display 160 ± 5 kPa and 40 ± 5 respectively (the ISAT may display slightly lower values when measuring at high altitude).

- If any measured value is incorrect, replace the pressure sensor.
- If the measured values are correct, continue with step 6.

5. Carry out continuity measurement on the wiring between the ECM and the 3-pole connector of the pressure sensor.

- Check the wires for open circuits/short circuits and any stray currents.
- If the measured values are correct, continue with step 6.

6. Erase the diagnostic trouble code and drive the car to see whether the DTC is generated again.

- If the diagnostic trouble code is registered, continue at "Procedure before replacing ECM".
- If the diagnostic trouble code is not registered, the action taken is correct. Otherwise the fault is intermittent in nature.