From Ross-Tech Wiki

18074/P1666 - Valve for Pump - Jet: Cylinder 1 (N240): Electrical Malfunction

Possible Symptoms

  • Irregular rpm

Possible Causes

  • Wiring and/or connections to/from the Valve for Pump Jet
  • Valve for Pump Jet

Possible Solutions

  • Check wiring and Check / Clean all connections
  • Replace the cable-tree to/from all the Valves for Pump Jet
  • Replace Valve for Pump Jet (replace them all !)

Special Notes

  • For each Valve the ECU checks the Begin of Injection Period (BIP) via a voltage. That voltage is very small (less than 0.0001A). Each extra resistance in the cable is fatal. So, in case of any doubt, just replace all cables.