P1635 CHEVROLET - 5-Volt Reference Circuit Low Conditions
- A/C Pressure sensor harness is open or shorted
- MAP sensor harness is open or shorted
- EGR valve harness is open or shorted
When is the code detected?
- Engine Light ON (or Service Engine Soon Warning Light)
P1635 Chevrolet Description
The Powertrain Control Module (PCM) uses a common 5.0 Volt Reference 1 circuit as a sensor feed. This circuit supplies 5 Volts to the following sensors: The Air Condition (A/C) Pressure sensor, the Manifold Absolute Pressure (MAP) sensor, and the Engine Gas Recirculation (EGR) valve. The PCM monitors the voltage on the 5.0 Volt Reference 1 circuit.