PCM 5 Volt Reference Voltage Circuit Condition
Table of contents
P1639 SATURN Possible Causes
- Sensor using 5 volt reference line shorted to ground
- Circuit short to ground
How do I fix code P1639 SATURN?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the P1639 SATURN code
The cost of diagnosing the P1639 SATURN code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
When is the code detected
If the voltage is out of tolerance, the Powertrain Control Module (PCM) will set DTC P1639.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1639 SATURN Description
The Powertrain Control Module (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.