LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Pontiac >> 2003 >> Aztek AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Diagnostic Tests >> DTC P1639: 5-Volt Reference 2 Circuit >> Description
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

DTC P1639: 5-Volt Reference 2 Circuit: Description

PCM uses the 5-volt reference 2 circuit as a sensor feed for the A/C refrigerant pressure sensor. The PCM monitors the voltage on the 5-volt reference 2 circuit. If voltage is out of tolerance, DTC P1639 will set.