Circuit Description

The accelerator pedal position (APP) sensor 1 is a potentiometer type sensor with the following three circuits:

• A 5-volt reference circuit
• A low reference circuit
• A signal circuit

The control module provides the APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensor then provides the control module a signal voltage proportional to pedal movement. The APP sensor 1 signal voltage is low at rest and increases as the pedal is depressed. This DTC incorporates the following diagnostic tests:

• The APP sensor 1 signal circuit voltage out of range
• The accelerator pedal minimum position for the APP sensor 1 out of range
• The 5-volt reference of the APP sensor 1 voltage out of range

If the PCM detects one or more of the APP sensor 1 tests are out of range, DTC P2120 sets.