5 Volt Reference 2 Circuit
2002-2007 Buick Rendezvous 3.5L V6
Description
The PCM detected that the 5-volt reference B circuit voltage is out of tolerance. This is a separate 5V reference circuit from P1635 and feeds a different set of sensors.
Symptoms
- Check Engine Light
- Engine stalling
- Multiple sensor DTCs
- Poor drivability
- Loss of power
Common Causes
- Short to ground in a connected sensor circuit
- Damaged sensor wiring
- Faulty sensor on this reference
- PCM 5V reference driver failure
Diagnostic Steps
- Measure 5V reference 2 voltage
- Disconnect sensors one at a time on this circuit
- Inspect wiring for shorts
- Test PCM output
Repair Notes
Same diagnostic approach as P1635. Disconnect sensors one at a time to isolate the shorted circuit.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1639 on Other Vehicles
Common Questions
What does code P1639 mean on a 2002-2007 Buick Rendezvous?
P1639 stands for "5 Volt Reference 2 Circuit". The PCM detected that the 5-volt reference B circuit voltage is out of tolerance. This is a separate 5V reference circuit from P1635 and feeds a different set of sensors.
What are the symptoms of P1639 on a Buick Rendezvous?
Common symptoms of P1639 include: Check Engine Light, Engine stalling, Multiple sensor DTCs, Poor drivability, Loss of power.
What causes P1639 on a 2002-2007 Buick Rendezvous?
Common causes of P1639 include: Short to ground in a connected sensor circuit, Damaged sensor wiring, Faulty sensor on this reference, PCM 5V reference driver failure.