With Manufacturer's Scan Tool

Wastegate Bypass Regulator valve -N75-, checking
- Switch ignition off.
- Disconnect Wastegate Bypass Regulator valve.
- Measure resistance between valve terminals.





Engine code ALH
Specification: 14 to 20 Ohms

If specification not obtained:
- Replace Wastegate Bypass Regulator valve -N75-.

If specification obtained:
- Switch ignition on.





- Measure supply voltage at valve connector terminal 1 and at engine Ground.
Specification: approximately battery voltage

If specification not obtained:
- Switch ignition off.





- Connect test box VAG 1598/22 to ECM wiring harness.
- Check wiring for open circuit between Test Box and harness connector using Wiring diagram.
Up to MY 1999
^ Terminal 1 + sockets 2 + 28
^ Terminal 2 + socket 15
From MY 2000
^ Terminal 1 + sockets 1 + 2
^ Terminal 2 + socket 62
Wire resistance: 1.5 Ohms Maximum
- Check wires for short to one another, to vehicle Ground and to battery Plus.
Specification: infinite Ohms

If wiring OK
- Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248-: