P1639 Lexus 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 Lexus.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1639 Lexus 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.
Lexus Vehicle:Lexus ES,Lexus GS,Lexus GX,Lexus HS,Lexus IS,Lexus LFA,Lexus LS,Lexus LX,Lexus RX,Lexus RX,Lexus SC,Lexus GS350,Lexus GS450H,Lexus IS250,Lexus GX460,Lexus IS350,Lexus LS460,Lexus LS600H,Lexus LX570,Lexus RX350