Circuit Description

The powertrain control module (PCM) provides 5 volts to the following sensors:

• The air conditioning (A/C) pressure sensor.
• The fuel tank pressure (FTP) sensor, if equipped.

These 5-volt reference circuits are independent of each other outside the PCM, but are bussed together inside the PCM. Therefore, a circuit condition on one sensor 5-volt reference circuit may affect the other sensor 5-volt reference circuits. The PCM monitors the voltage on the 5-volt reference circuit. If the PCM detects that the voltage is out of tolerance, DTC P0651 sets.