5 Volt Reference 1 Circuit
2002-2007 Buick Rendezvous 3.5L V6
Description
The PCM detected that the 5-volt reference A circuit voltage is out of tolerance. This circuit provides the sensor feed voltage for multiple sensors including the MAP sensor, TP sensor, EGR valve position sensor, and fuel tank pressure sensor. A fault here can affect multiple systems simultaneously.
Symptoms
- Check Engine Light
- Engine stalling
- Rough idle
- Poor performance
- Multiple sensor codes may set
- Loss of power
Common Causes
- Short to ground in one of the sensors connected to the 5V reference
- Damaged sensor wiring
- Faulty sensor drawing excessive current
- Defective PCM 5V reference driver
- Fuel pump harness shorted to fuel tank pressure sensor
Diagnostic Steps
- Measure 5V reference voltage at multiple sensors
- Disconnect sensors one at a time to isolate short
- Inspect fuel pump harness for shorts to FTP sensor
- Check sensor wiring for chafing or damage
- Test PCM 5V reference output
Repair Notes
Disconnect sensors one at a time to find which sensor circuit is pulling the reference low. Inspect fuel pump harness. Repair shorted wiring. This is a root-cause code that can trigger many other sensor DTCs.
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
P1635 on Other Vehicles
Common Questions
What does code P1635 mean on a 2002-2007 Buick Rendezvous?
P1635 stands for "5 Volt Reference 1 Circuit". The PCM detected that the 5-volt reference A circuit voltage is out of tolerance. This circuit provides the sensor feed voltage for multiple sensors including the MAP sensor, TP sensor, EGR valve position sensor, and fuel tank pressure sensor. A fault here can affect multiple systems simultaneously.
What are the symptoms of P1635 on a Buick Rendezvous?
Common symptoms of P1635 include: Check Engine Light, Engine stalling, Rough idle, Poor performance, Multiple sensor codes may set, Loss of power.
What causes P1635 on a 2002-2007 Buick Rendezvous?
Common causes of P1635 include: Short to ground in one of the sensors connected to the 5V reference, Damaged sensor wiring, Faulty sensor drawing excessive current, Defective PCM 5V reference driver, Fuel pump harness shorted to fuel tank pressure sensor.