Captiva

DTC P2122, P2123, P2127, P2128, or P2138 - LNP or LNQ

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 V 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 more than 2 V with the accelerator pedal fully depressed.

P2122 00

The APP sensor 1 voltage is less than 0.59 V for more than 4 s.

P2123 00

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

P2127 00

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

P2128 00

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

P2138 00

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

DTCs P2122 00, P2123 00, P2127 00, P2128 00 and P2138 00 are Type A DTCs.

DTCs P2122 00, P2123 00, P2127 00, P2128 00 and P2138 00 are Type A 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 for scan tool information

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 and release pedal. Repeat the procedure several times. DTCs P2122 00, P2123 00, P2127 00, P2128 00 or P2138 00 should not set.
3. Slowly depress the accelerator pedal to wide open throttle position and then slowly return the pedal to closed throttle. Repeat the procedure several times. DTCs P2122 00, P2123 00, P2127 00, P2128 00 or P2138 00 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 of resistance between the appropriate low reference circuit and ground.

•	B107 Accelerator Pedal Position Sensor 1 low reference circuit terminal D

•	B107 Accelerator Pedal Position Sensor 2 low reference circuit terminal C

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

Note: The 5 V 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.

•	B107 Accelerator Pedal Position Sensor 1 5 V reference circuit terminal F

•	B107 Accelerator Pedal Position Sensor 2 5 V reference circuit terminal A

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

4. Verify the appropriate scan tool APP sensor parameter is less than 0.3 V.

•	B107 Accelerator Pedal Position Sensor 1 signal circuit terminal E

•	B107 Accelerator Pedal Position Sensor 2 signal circuit terminal B

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

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

⇒	If less than the specified range, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuit tests 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 being shorted together condition. If the circuit tests 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.