Cruze

DTC P2120, P2125, or P2138

The accelerator pedal assembly contains two 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 V at rest to above 4 V when fully depressed. The APP sensor 2 signal voltage increases as the pedal is depressed, from approximately 0.5 V at rest to greater than 2 V with the accelerator pedal fully depressed.

P2120 03

The APP sensor 1 voltage is out of range for greater than 4 s.

P2120 07

The APP sensor 1 voltage is greater than 4.62 V for greater than 4 s.

P2125 03

The APP sensor 2 voltage is less than 0.28 V for greater than 4 s.

P2125 07

The APP sensor 2 voltage is greater than 2.32 V for greater than 4 s.

P2138 5A

The ECM detects that the voltage difference between APP sensor 1 and 2 is greater than a predetermined value.

DTCs P2120, P2125, and P2138 are Type C DTCs.

DTCs P2120, P2125, and P2138 are Type C DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References

1. Ignition ON, observe the scan tool APP Sensor parameters. Both readings should be between 0.4-1.5 V.
2. Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times. DTCs P2120, P2125, or P2138 should not set.
3. Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. DTCs P2120, P2125, or P2138 should not set.
4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the B107 Accelerator Pedal Position Sensor.
2. Test for less than 5 Ω between the appropriate low reference circuit and ground.

•	APP Sensor 1 low reference circuit terminal 4

•	APP Sensor 2 low reference circuit terminal 5

⇒	If greater than the specified range, test the low reference circuit for a short to voltage, or an open/high resistance. If the circuits test normal, replace the K20 Engine Control Module.

Note: The 5-volt reference circuits are internally and externally connected at the ECM. Other component DTCs may be set. If other DTCs are set, review the electrical schematic and diagnose the applicable circuits and components.

3. Ignition ON, test for 4.8-5.2 V between the appropriate 5 V reference circuit and ground.

•	APP Sensor 1 5 V reference circuit terminal 2

•	APP Sensor 2 5 V reference circuit terminal 1

⇒	If less the specified range, test the 5 V reference circuit for a short to ground or open/high resistance. If the circuits test normal, replace the K20 Engine Control Module.

⇒	If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuits test normal, replace the K20 Engine Control Module.

4. Verify both scan tool APP sensor parameters are less than 0.3 V.

⇒	If greater than the specified range, test the appropriate signal circuit for a short to voltage. If the circuits test normal, replace the K20 Engine Control Module.

5. Install a 3 A fused jumper wire between the appropriate signal circuit and the 5-volt reference circuit. Verify the scan tool APP sensor parameter is greater than 4.8 V.

•	APP Sensor 1 signal circuit terminal 3

•	APP Sensor 2 signal circuit terminal 6

⇒	If less than the specified range, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the K20 Engine Control Module.

⇒	If both scan tool APP sensor parameters display greater than the specified range, test the signal circuits for a shorted together condition. If the circuits test normal, replace the K20 Engine Control Module.

6. If all circuits test normal, replace the B107 Accelerator Pedal Position Sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.