Chevrolet P1639: 5-Volt Reference 2 Circuit Malfunction
Is your scanner showing Chevrolet P1639?
No worries. We'll show you what it means and how to deal with it.
Chevrolet P1639: 5-Volt Reference 2 Circuit Malfunction
OVERVIEWWhat Does The Chevrolet P1639 Code Mean?
Key on or engine running; and the PCM detected the 5v Reference No. 2 circuit was out of range for 2 seconds. The 5v VREF 2 circuit connects to the A/C Refrigerant pressure sensor.
What Are The Potential Causes Of The Chevrolet P1639 Code?
- 5v VREF circuit is shorted to sensor ground or chassis ground
- 5v VREF circuit, A/C pressure sensor circuit is shorted to (B+)
- 5v VREF circuit shorted to A/C pressure sensor signal circuit
- A/C refrigerant pressure sensor is damaged or PCM has failed
Recommended Parts
Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:
>>> WORKPRO 582-piece Crimp Terminals, Wire Connectors, Heat Shrink Tube, Electrical Repair Kit
>>> GM Genuine Parts 12633238 Engine Control Module
>>> ACDelco GM Original Equipment 15-51343 Air Conditioning Refrigerant Pressure Sensor
Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!
Reference Sources
- 2000 Chevrolet Camaro and Pontiac Firebird Service Manual – Volume 1, page 1395.
- GM, 2013, Service Bullettin – Prior To Any Circuit Testing.
