P1639 JEEP PCM 5 Volt Reference Voltage Circuit Condition
Possible causes
– Sensor using 5 volt reference line shorted to ground
– Circuit short to ground
– Circuit short to ground
What about the obd code?
If the voltage is out of tolerance, the PCM will set DTC P1639 JEEP.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1639 JEEP 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.
JEEP Vehicle:JEEP Commander,JEEP Compass,JEEP Grand Cherokee,JEEP Liberty,JEEP Patriot,JEEP Wrangler,JEEP Wrangler Unlimited,