P0642 Audi Sensor Voltage Circuit A Low Voltage

P0642 Audi Sensor Voltage Circuit A Low Voltage

Possible causes
– Faulty Engine Control Module (ECM)
– ECM harness is open or shorted
– ECM circuit poor electrical connection
– Shorted sensor on 5 volt circuit
Tech description
There is a factory service bulletin for the P0642 Audi code for the following models:

2005-2007 Audi A3
2005-2007 Audi A4
2007 Audi A4 Cabriolet
2008 Audi TT
Audi Factory Service Bulletin OBDII Code P0642 Audi

What about the obd code?
The Engine Control Module (ECM) has detected the sensor 5 volt reference circuit voltage is lower than expected
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
Audi Vehicle:Audi A1,Audi A3,Audi A1,Audi A3,Audi A1,Audi A3,Audi A4,Audi A5,Audi Q3,Audi A5,Audi Q5,Audi A3,Audi A4,Audi A5,Audi TT,Audi Q3,Audi Q5,Audi S3,Audi TTS,Audi RS 3,Audi TT RS,Audi A7,Audi Q7,Audi A8,Audi A6,Audi S4,Audi S5,Audi Q5,Audi S6,Audi S8,Audi S5,Audi A8,Audi R8 V8,Audi RS 5,Audi S6,Audi R8 V10,Audi R8 GT,Audi A8L