DTC P2125

Circuit Description

The accelerator pedal position (APP) sensors 1 and 2 are located within the accelerator pedal assembly. Each sensor has the following circuits:

This provides the engine control module (ECM) with a signal voltage proportional to accelerator pedal movement. The APP sensors have opposite functionality. APP sensor 1 signal voltage increases as the pedal is depressed, from below 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 not within the predicted range, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2125 Accelerator Pedal Position (APP) Sensor 2 Circuit

Conditions for Running the DTC

Conditions for Setting the DTC

The APP sensor 2 voltage is less than 0.3625 volt or more than 4.225 volts for more than 0.4 second.

Action Taken When the DTC Sets

Conditions for Clearing the MIL/DTC

    

The control module turns OFF the malfunction indicator lamp (MIL) after 3 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.

 

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool, observe the accelerator pedal position (APP) sensor 2 voltage with the accelerator pedal in the rest position.

Does the scan tool indicate voltage less than the first value or greater than the second value?

0.3625 V

4.225 V

Go to Step 4

Go to Step 3

3

  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Does the DTC fail this ignition?

--

Go to Step 4

Go to Intermittent Conditions

4

  1. Turn OFF the ignition.
  2. Disconnect the accelerator pedal harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the APP Sensor 2 Voltage parameter with a scan tool.

Does the scan tool indicate voltage more than the specified value?

4 V

Go to Step 5

Go to Step 13

5

Probe the APP sensor 2 signal circuit with a test lamp connected to ground.

Does the test lamp illuminate?

--

Go to Step 12

Go to Step 6

6

Observe the APP Sensor 2 parameter with the test lamp still connected to the APP sensor 2 signal circuit.

Does the scan tool indicate voltage at the specified value?

0 V

Go to Step 7

Go to Step 11

7

Measure the voltage of the APP sensor 2 5-volt reference circuit with a DMM.

Does the DMM indicate voltage at the specified value?

5 V

Go to Step 8

Go to Step 10

8

Probe the APP sensor 2 low reference circuit with a test lamp connected to B+.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 14

9

Test the APP sensor low reference circuit for a short to ground.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 18

10

Does the DMM indicate voltage less than the specified value on the APP sensor 2 5-volt reference circuit?

5 V

Go to Step 15

Go to Step 17

11

Test the APP sensor 2 signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 13

12

Test the APP sensor 2 signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 20

13

Test the APP sensor 2 signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 20

14

Test the APP sensor 2 low reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 20

15

Test the APP sensor 2 5-volt reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 16

16

Test the APP sensor 2 5-volt reference circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 20

17

Test the APP sensor 2 5-volt reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

--

18

Inspect for poor connections at the accelerator pedal harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 19

19

Replace the accelerator pedal assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement .

Did you complete the replacement?

--

Go to Step 22

--

20

Inspect for poor connections at the engine control module (ECM) harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 21

21

Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 22

--

22

  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze/Frame Failure Records.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 23

23

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK