P2128
DTC P2128
CIRCUIT DESCRIPTION
The accelerator pedal assembly contains 2 accelerator pedal position (APP) sensors. The APP sensors are mounted in the pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to the position of the accelerator pedal. The engine control module (ECM) supplies a separate 5-volt reference and low reference circuit for each of the APP sensors.
The APP sensor 1 signal voltage increases as the pedal is depressed, from approximately 1 volt at rest to above 2.5 volts when fully depressed. The APP sensor 2 signal voltage decreases as the pedal is depressed, from approximately 4 volts at rest to less than 1 volt with the accelerator pedal fully depressed.
If the ECM detects that the APP sensor 2 signal voltage is too high, this DTC sets.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P2128 Accelerator Pedal Position (APP) Sensor 2 Circuit High Voltage
CONDITIONS FOR RUNNING THE DTC
- DTCs P0601, P0602, P0603, P0604, P0606, P0607, P0641, P0651 are not set.
- The ignition is ON.
- The ignition 1 voltage is more than 5.23 volts.
- DTC P2128 runs continuously when the above conditions are met.
CONDITIONS FOR SETTING THE DTC
The ECM detects that the APP sensor 2 voltage is more than 4.2 volts for more than one second.
ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 4 consecutive ignition cycles that the diagnostic runs and does not fail.
- 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 emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.
DIAGNOSTIC AIDS
- Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
- If DTCs P0700, P2122, P2128, and P2138 are set together in various combinations, inspect the APP sensor 1 and 2 signal circuits for being shorted together.
- For an intermittent condition, refer to Intermittent Conditions. Diagnostic Strategies
TEST
