Circuit Description

The engine control module (ECM) provides a 5-volt reference to the following sensors:

• The manifold absolute pressure (MAP) sensor
• The accelerator pedal position (APP) sensor 1
• The fuel level sensor 2

The ECM monitors voltage on the 5-volt reference circuit. If the ECM detects that the voltage on the 5-volt reference circuit is outside a calibrated range, DTC P0641 will set.