From Ross-Tech Wiki

16500/P0116/000278 - Engine Coolant Temp. Sensor (G62): Implausible Signal

Possible Symptoms

  • Starting the engine when engine is warmish or warm, idle rpm immediately is 1200 - 3000 rpm.
    • Diesel: an indication is extreme long time burning time of the glow indication light.
  • With all engine temperatures seldom idle rpm will vary between 900 - 1000 rpm.
  • With engine warm (90 °C) the engine temperature suddenly drops (70 °C) and slowly comes back to 90 °C.

Possible Causes

  • Wiring and/or connections faulty
  • Engine Coolant Sensor (G62) faulty

Possible Solutions

  • Check wiring and connections
  • Replace Engine Coolant Sensor (G62)

Special Notes

  • In MY 1995-2002 (?) in Europe at VW-cars the G2/G62 had the bad reputation of breaking down often. The default G2/G62 is black and all replacements are green.
  • Check if the correct Coolant Fan Control Module/Relay is installed (check part number using parts catalogue)!