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DTC P2101 > < Symptoms - Engine Controls

Astra J

DTC P2122, P2123, P2127, P2128, or P2138

Diagnostic Instructions

•  Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
•  Review Strategy Based Diagnosis for an overview of the diagnostic approach.
•  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P2122 00: Accelerator Pedal Position (APP) Sensor 1 Circuit Low Voltage
DTC P2123 00: Accelerator Pedal Position (APP) Sensor 1 Circuit High Voltage
DTC P2127 00: Accelerator Pedal Position (APP) Sensor 2 Circuit Low Voltage
DTC P2128 00: Accelerator Pedal Position (APP) Sensor 2 Circuit High Voltage
DTC P2138 00: Accelerator Pedal Position (APP) Sensors 1-2 Not Plausible
DTC P2138 38: Accelerator Pedal Position (APP) Sensors 1-2 Not Plausible

Diagnostic Fault Information



Circuit
Short to Ground
High Resistance
Open
Short to Voltage
Signal Performance

Accelerator Pedal Position (APP) Sensor 1 5V Reference Circuit
P0641 00
P2138 00, P2138 38
P2122 00
P0641 00
-

Accelerator Pedal Position (APP) Sensor 2 5V Reference Circuit
P0651 00
P2138 00, P2138 38
P2127 00
P0651 00, P0190 00
-

Accelerator Pedal Position (APP) Sensor 1 Signal
P2120 00
P2138 00, P2138 38
P2122 00
P0641 00, P2120 00
P2138 00, P2138 38

Accelerator Pedal Position (APP) Sensor 2 Signal
P2125 00
P2138 00, P2138 38
P2127 00
P2128 00
P2138 00, P2138 38

Accelerator Pedal Position (APP) Sensor 1 Low Reference
-
P2138 00, P2138 38
P2122 00
P2123 00
-

Accelerator Pedal Position (APP) Sensor 2 Low Reference
-
P2138 00, P2138 38
P2127 00
P2128 00
-
 

Typical Scan Tool Data


APP Sensor


Circuit
Short to Ground
Open
Short to Voltage


Operating Conditions: The engine is operating at idle


Parameter Normal Range: APP Sensor 1 0.9-1.2 V


Parameter Normal Range: APP Sensor 2 varies 0.45-0.62 V

5V Reference 1
0 V
0 V
APP 1 2.08 V

5V Reference 2
0 V
0 V
APP 2 0.86 V

APP Sensor 1 Signal
0 V
0 V
5 V

APP Sensor 2 Signal
0 V
0 V
5 V

APP Sensor 1 Low Reference
-
5 V
-

APP Sensor 2 Low Reference
-
5 V
-
 

Circuit/System Description

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.

Conditions for Running the DTC

•  The ignition is ON or the engine is operating.
•  The DTCs run continuously once the above conditions are met.

Conditions for Setting the DTC

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 and P2138 38

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

Action Taken When the DTC Sets

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

Conditions for Clearing the DTC

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

Reference Information


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

Circuit/System Verification

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, P2123, P2127, P2128 or P2138 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, P2123, P2127, P2128 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.

Circuit/System Testing

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 4
  •  B107 Accelerator Pedal Position 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 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 2
  •  B107 Accelerator Pedal Position 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 the appropriate scan tool APP sensor parameter is less than 0.3 V.
  •  B107 Accelerator Pedal Position Sensor 1 signal circuit terminal 3
  •  B107 Accelerator Pedal Position Sensor 2 signal circuit terminal 6
⇒ 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 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 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 being 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.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•  Control Module References for engine control module replacement, setup and programming

DTC P2101 > < Symptoms - Engine Controls