Wife's MIL light came on in her 06 Golf today. Pulled the code and it traced back to the coolant temp sensor. The sensor is responsible for the readings on the gage as well as sending a signal to the ECM that tells the computer if the engine is hot or cold and if it should run in closed or open loop mode.
Apparently, its not unusual for the signal to the ECM from the sensor to go all wacky. Its an easy 2 minute replacement (pull a clip, pull sensor, unplug harness, plug in new sensor to harness, replace o ring and clip), but I learned after some research, to make sure you buy the part from the dealer which runs like $30 including a new o-ring.
You can pick up a aftermarket Beck Arnley sensor for $23 or a BWG for $10 but these will fail in short order as well. The dealer part is a new design (a green sensor body is the clue that its the redesigned part).
This affects many VW models/engines spanning from about 2000 to 2007.
Apparently, its not unusual for the signal to the ECM from the sensor to go all wacky. Its an easy 2 minute replacement (pull a clip, pull sensor, unplug harness, plug in new sensor to harness, replace o ring and clip), but I learned after some research, to make sure you buy the part from the dealer which runs like $30 including a new o-ring.
You can pick up a aftermarket Beck Arnley sensor for $23 or a BWG for $10 but these will fail in short order as well. The dealer part is a new design (a green sensor body is the clue that its the redesigned part).
This affects many VW models/engines spanning from about 2000 to 2007.
