Engine Coolant Temperature Sensor Signal Too High and N75 Open Circuit : Related?


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Nov 15, 2012
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Hi Guys,

My car (S3 8L 210) has been struggling to start recently (and the temperature gauge had stopped working) so thought i would get it a quick scan.

I got two fault codes : 16502 Engine Coolant Temperature Sensor (G62) Signal too high intermittent
And 7956 Boost Pressure Regulator Valve N75 Open Circuit P1548 -35 -10 Intermittent

The N75 fault has been floating around for a while even after replacing a large section of wiring (Not sure what to do now????? Any ideas?)

The other fault is new and looking at Ross Tech it seems a common problem however one of the known issues is do to with
wiring, and i think (Assuming i am looking at the correct sensor) noticed the wires for both come into the same protective sleeve, do i have some underlying electrical issue or is it just coincidence?

Any ideas would be great.

Taken From Ross Tech:
Possible Causes

  • The electrical signal coming from G62 is too low
  • Wiring and/or connections faulty (short circuit?)
  • Engine Coolant Temperature Sensor (G62) faulty
Possible Solutions

  • Check wiring and connections
  • Check / Replace Engine Coolant Temperature Sensor (G62)
Special Notes

  • In many cars between MY 1995-2002 the G2/G62 had a bad reputation for failing often. The original G2/G62 sensor is black and the improved replacements are green.

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