Volkswagen Workshop Service and Repair Manuals

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

Special tools, testers, measuring instruments and auxiliary items required

• ◆ Test box V.A.G 1598/18
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Electrically checking needle lift sender (G80).

• ‒ Switch off ignition.
• ‒ Disconnect connector for sender =>Fitting locations overview, Page 23-4 .
• ‒ → Carry out resistance measurement between connector contacts using hand multimeter V.A.G 1526.
       Specification: 80 ... 120 ω

If the specification is not attained:

• ‒ Replace injector cylinder 3 with needle lift sender (G80).

Checking wiring connections to needle lift sender (G80)

• ‒ Switch off ignition.
• ‒ Disconnect connector for sender =>Fitting locations overview, Page 23-4 .
• ‒ Connect test box =>Page 23-34 .

The following wiring connections are to be checked for open circuits and/or short to positive or negative.

• ‒ → Wiring from connector contact 1 to test box socket 12.
• ‒ Wiring from connector contact 1 to test box socket 11.
• ‒ If neither an open or short circuit exists, renew Diesel direct injection system control unit.