From Ross-Tech Wiki
16501/P0117 - Engine Coolant Temperature Sensor (G62): Signal too Low
- Difficulties with starting a cold engine.
- Starting the engine when engine is warmish or warm, idle rpm immediately is 1200 - 3000 rpm.
- RPM at idle is irregular.
- 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.
- Bad acceleration during warming up.
- Diesel: an indication is extreme long time burning time of the glow indication light.
- Engine Overheating
- The electrical signal coming from G62 is too low
- Wiring and/or connections faulty (short circuit?)
- Engine Coolant Temperature Sensor (G62) faulty
- Mechanical problems in cooling system
- Check wiring and connections
- Check / Replace Engine Coolant Temperature Sensor (G62)
- Check cooling system and correct overheating condition if present
- 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.