P0642 Cadillac Sensor Voltage Circuit A Low Voltage

P0642 Cadillac 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 Cadillac 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 Cadillac

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)
Cadillac Vehicle:Cadillac CTS Coupe, Cadillac CTS-V Coupe , Cadillac Eldorado , Cadillac Escalade EXT , Cadillac ATS , Cadillac CTS , Cadillac CTS Sedan , Cadillac CTS Sport Sedan , Cadillac CTS-V , Cadillac CTS-V Sedan , Cadillac Catera , Cadillac DTS , Cadillac DeVille , Cadillac STS-V , Cadillac STS , Cadillac Seville , Cadillac XTS , Cadillac XLR , Cadillac XLR Platinum , Cadillac Escalade , Cadillac SRX