Needle Lift Sensor, Checking

NOTE: The Needle lift sensor signal is used to determine the "Start of injection "If it falls; 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).


Special tools, workshop equipment, testers, measuring instruments and auxiliary items required
- VAG 1598/22 Test Box
- Fluke 83 multimeter
- VW 1594 Adaptor kit
- Wiring diagram

Test sequence

- Switch OFF ignition.
- Disconnect Needle lift sensor harness connector. Service and Repair
- Measure resistance between connector terminals.
- Specification: 80 to 120 ohms







If specification not obtained:
- Replace cyl. 3 fuel injector with needle lift sensor G80, refer to "Diesel Injection Pump, Servicing". Service and Repair

If specification obtained
- Connect VAG 1598/22 Test Box to ECM wiring harness.







- Check wiring for open circuit between Test Box and harness connector using Wiring diagram.
- Terminal 1 + socket 62
- Terminal 2 + socket 55
- Wire resistance: max. 1.5 Ohms







- Check wires for short to one another; to vehicle Ground and to battery Plus
Specification: Infinity Ohms

If wiring OK
- Replace Diesel direct injection system ECM J248.
- Display Readiness code. Testing and Inspection

If DTC memory has been erased
- Create Readiness code. Testing and Inspection