DTC P1635: 5-Volt Reference 1 Circuit: Description

The Powertrain Control Module (PCM) uses the 5-volt reference 1 circuit as a sensor feed to the following sensors:

• The Throttle Position (TP) sensor.
• The Manifold Absolute Pressure (MAP) sensor.

The Powertrain Control Module (PCM) monitors the voltage on the 5-volt reference 1 circuit. If the voltage is out of tolerance, the PCM will set DTC P1635.