Wastegate Bypass Regulator Valve, Checking

Wastegate Bypass Regulator Valve N75 , checking

Special tools, testers and auxiliary items required
- Multimeter
- Wiring diagram

Test requirements
- The Motronic Engine Control Module (ECM) J220 fuses OK.
- The Fuel Pump (FP) Relay J17 OK.
- Battery voltage at least 12.5 volts.
- All electrical consumers such as, lights and rear window defroster, switched off.
- On vehicles with automatic transmission, selector lever in position "P" or "N".
- A/C switched off.
- Ground (GND) connections between engine/transmission/chassis OK.
- Ignition switched off.

Note:
Voltage for the Wastegate Bypass Regulator Valve N75 is supplied by the Fuel Pump (FP) Relay J17.

Test procedure
- Perform a preliminary check to verify the customers complaint. Service and Repair

Start diagnosis
- Remove the engine cover with air filter.

Checking internal resistance






- Disconnect the Wastegate Bypass Regulator Valve N75 electrical harness connector -2-.






- Using a multimeter, check the Wastegate Bypass Regulator Valve N75 terminals 1 to 2 for resistance.

Specified value: 25 to 35 Ohms (at approx. 20�C)

If the specification was not obtained:

- Replace the Wastegate Bypass Regulator Valve N75.

If the specification is obtained:

Checking Voltage supply






- Using a multimeter, check the Wastegate Bypass Regulator Valve N75 electrical harness connector terminal 1 to Ground (GND).






- Operate the starter briefly.

Specified value: battery voltage.

- Switch the ignition off.

If the specification was not obtained:

- Check the wiring for a short circuit to Battery positive (+) or an open circuit.

- Check the electrical harness connector for damage, corrosion, lose or broken terminals.

- If necessary, repair the wiring connection.

If no malfunction is found in the wiring:

If the manufacturers test box is being used. Perform the following step.

- Install the test box Test Box 105 Pin VAG1598/31.

If the manufacturers test box is not being used. Perform the following step.

- Remove the Motronic Engine Control Module (ECM) J220. Service and Repair






- Using a multimeter, check the Wastegate Bypass Regulator Valve N75 electrical harness connector terminal 2 to the Motronic Engine Control Module (ECM) J220 electrical harness connector T121 terminal 104 for an open circuit.






Specified value: 1.5 Ohms max.

If the specification is not obtained:

- Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

- Check the electrical harness connector for damage, corrosion, lose or broken terminals.

- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring and if the voltage supply was OK:

- Erase the DTC memory. Diagnostic Mode 4: Reset/Erase Diagnostic Data

- Perform a road test to verify repair.

If the DTC does not return:

Repair complete, Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

- End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:

- Replace the MFI Engine Control Module (ECM) J220. Service and Repair

- Assembly is performed in the reverse of the removal.

Final procedures

After the repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory.
2. If necessary, erase the DTC memory.
3. If the DTC memory was erased, generate readiness code.

End diagnosis