With Manufacturer's Scan Tool

Needle Lift Sensor -G80-, Checking

The needle lift sensor signal is used to determine the start of injection. If it fails the start of injection switches to open-loop control (using engine speed and engine load). During normal operation the start of injection is controlled by a closed-loop function (using engine speed, engine load and engine coolant temperature).

NOTE: The gold-plated contacts must be used to repair terminals in the connector for the needle lift sensor -G80-.

Special tools and equipment
- Test box VAG 1598/31
- Hand multimeter VAG 1526 or multimeter VAG 1715
- Adapter set VAG 1594
- Wiring diagram

Test sequence
- Switch off ignition.






- Disconnect the 2-pin connector from needle lift sensor -arrow-.






- Measure resistance between connector contacts.
Specification: 80 to 120 Ohm

If the specification is not obtained:
- Replace No. 3 cylinder injector with needle lift sensor -G80-, item 18 .
- Check DTC memory and, if necessary, repair any malfunctions and then erase. [1][2]Reading Diagnostic Trouble Codes
- Read-out the readiness code. If the DTC memory has been erased or the Diesel Direct Fuel Injection Engine Control Module -J248- was disconnected from permanent battery positive (B+), the readiness code must be generated again.
Monitors, Trips, Drive Cycles and Readiness Codes
Monitors, Trips, Drive Cycles and Readiness Codes

If the specification is obtained:
- Remove wiper arms and plenum cover.






- Connect test box VAG 1598/31 to control unit wiring harness.






- Check wiring between test box and connector for open circuit according to wiring diagram.
Terminal 1 + socket 109
Terminal 2 + socket 101
Wire resistance: max. 1.5 Ohm

- Check wires for short to one another, to vehicle Ground and to battery positive (B+).
Specification: Infinite Ohm

If no fault is detected in the wiring:
- Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248-.