Wastegate Bypass Regulator Valve -N75-, Checking

Wastegate Bypass Regulator Valve -N75-, Checking







Special tools, testers and other equipment required
- V.A.G 1526 A Multimeter
- V.A.G 1527 B Voltage tester
- V.A.G 1594 A Connector test kit
- V.A.G 1598/31 Test box
- VAS 5051 Vehicle diagnosis, testing and information system with VAS 5051/1 Adapter
or
- V.A.G 1551 Scan Tool with V.A.G 1551/3 A Adapter

NOTE: Wastegate bypass regulator valve -N75- and its wiring are monitored by the engine control module.

- Connect vehicle diagnosis, testing and information system VAS 5051 (or scan tool V.A.G 1551) and select "Engine Electronics" control module by entering address word 01. Engine must be running at idling speed.

- Check DTC memory of engine control module.

If the display shows a malfunction relating to Wastegate bypass regulator valve -N75-
- Disconnect hoses from valve but leave electrical connector connected.
- Install an auxiliary hose to one of connections on valve.
- Start output diagnostic test mode and activate Wastegate bypass regulator valve -N75-.

Indicated on display:
Output Diagnostic Test Mode ->
Wastegate bypass regulator valve -N75

Valve should click and open and close (test by blowing into auxiliary hose).

If the valve does not click:
- Check internal resistance of valve.

If the valve does not open and close properly:
- Replace Wastegate bypass regulator valve -N75-.

Checking internal resistance
- Disconnect connector from valve.







- Connect multimeter to valve (resistance measurement range).

Specification: 25-35 Ohms

If the specification is not obtained:
- Replace Wastegate bypass regulator valve -N75-.

If the specification is obtained:

Checking voltage supply







- Connect voltage tester V.A.G 1527 B as follows:

Connector terminal Measure against
1 Engine ground (GND)

- Operate starter briefly.

LED should light up.

If the LED does not light up:
- Check for open circuit in wiring from terminal 1 to fuel pump relay via fuse

- Repair any open circuits.

If the wiring is OK:
- Check fuel pump relay.

If the LED lights up:
- Check activation.

Checking activation







- Connect voltage tester V.A.G 1527 B to terminal 1 (positive) and terminal 2 of connector.
- Start Output Diagnostic Test Mode (DTM) and activate Wastegate bypass regulator valve -N75-.

LED should flash.

If the LED lamp does not flash or lights up continuously:
- Connect test box V.A.G 1598/31 to wiring harness for engine control module. Do not connect engine control module itself.







- Check for open circuit and short to positive or ground (GND) in following wiring connections:

Connector terminal Measure against
2 104

- Repair short circuit or open circuit if necessary.

If the wiring is OK:
- Replace engine control module.