Modulating piston displacement sensor, checking
WARNING: This page is about a different car, the 1999 Volkswagen Jetta, 1998 Volkswagen Jetta, and 1997 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.
- Press --> button.
- Press buttons -0- and -6- to select "End Output" function 06.
- Press -Q- button to confirm input.
- Switch ignition off.
- Disconnect fuel temperature sensor harness connector (connection to fuel pump quantity adjuster).
- Measure resistance across connector terminals 1 and 2, and terminals 2 and 3.
Specification: 5 to 7 ohms (ohm)
If resistance is not as specified:
- Replace diesel fuel injection pump, see DIESEL INJECTION PUMP, REMOVING AND INSTALLING .
- Display readiness code, see READINESS CODE, DISPLAYING .
If DTC memory was erased:
- Create readiness code again, see READINESS CODE, SETTING (UP TO M.Y. 1997) .
If resistance is OK:
- Connect VAG1598/18 test box to Diesel DFI ECM connector.
- Check wiring for open circuit between test box and harness connector, using wiring diagrams:
- Terminal 1 and test box socket 29
- Terminal 2 and test box socket 7
- Terminal 3 and test box socket 52
- Wire resistance: max. 1.5 ohms (ohm)
- Check wiring for short circuit between connector terminals.
Specification: INFINITY ohm (no continuity)
If wiring is OK:
- Replace Diesel DFI ECM -J248-, see item 3 .
- Display readiness code, see READINESS CODE, DISPLAYING .
If DTC memory was erased:
- Create readiness code again, see READINESS CODE, SETTING (UP TO M.Y. 1997) .