P2120

DTC P2120

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. When the control module detects that the APP sensor 1 signal or APP sensor 5-volt reference voltage is outside the predetermined range, this DTC sets.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P2120 Accelerator Pedal Position (APP) Sensor 1 Circuit

CONDITIONS FOR RUNNING THE DTC
- DTCs P0601, P0602, P0606, P2108, or U0107 are not set.
- The ignition switch is in the crank or run position.
- The ignition voltage is more than 5.23 volts.
- This diagnostic runs continuously when the above conditions are met.

CONDITIONS FOR SETTING THE DTC
- The APP sensor 1 voltage is less than 0.24 volts or more than 4.49 volts.OR
- The 5-volt reference is less than 4.54 volts or more than 5.21 volts.
- One of the above conditions is present for more than 1 second.

ACTION TAKEN WHEN THE DTC SETS
- The control module stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
- If one or more APP sensor DTCs are set, the following occurs:
- The control module commands Reduced Engine Power mode.
- The APP indicated angle is limited to a predetermined value to limit the amount of throttle control.OR
- The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle.
- The message center displays Reduced Engine Power.

CONDITIONS FOR CLEARING THE DTC
- A current DTC Last Test Failed clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
- Clear the DTC with a scan tool.

DIAGNOSTIC AIDS
- Inspect the throttle actuator control (TAC) module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
- When the TAC module detects a condition within the TAC System, more than 1 TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
- For an intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-9:

Steps 10-18:

Steps 19-26:

The numbers below refer to the step numbers on the diagnostic table.
12. This test isolates whether the short is to another TAC System circuit in the harness or within the TAC module.
26. When the TAC module detects a condition within the TAC System, more than 1 TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.