锟斤拷If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit/connections test normal, replace
the ECM.
3. Ignition ON, test for 4.8-5.2 V between the appropriate 5 V reference circuit terminal listed below and ground.
* APP sensor 1 terminal D or 2
* APP sensor 2 terminal C or 1
锟斤拷If less than the specified range, test the 5 V reference circuit for a short to ground or open/high resistance. If the circuit/connections test
normal, replace the ECM.
锟斤拷If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit/connections test normal, replace the
ECM.
4. Observe the scan tool APP sensor 1 voltage parameter. Verify the voltage is less than 0.3 V.
锟斤拷If greater than the specified range, test the signal circuit terminal E or 3 for a short to voltage. If the circuit/connections test normal,
replace the ECM.
5. Observe the scan tool APP sensor 2 voltage parameter. Verify the voltage is less than 0.3 V.
锟斤拷If greater than the specified range, test the signal circuit terminal B or 6 for a short to voltage. If the circuit/connections test normal,
replace the ECM.
6. Connect a 3 A fused jumper wire between the APP sensor 1 signal circuit terminal E or 3 and the 5 V reference circuit terminal C or 1. Verify
the APP sensor 1 voltage parameter is greater than 4.8 V.
锟斤拷If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test
normal, replace the ECM.
7. Connect a 3 A fused jumper wire between the APP sensor 2 signal circuit terminal B or 6 and the 5 V reference circuit terminal C or 1.
Verify the APP sensor 2 voltage parameter is greater than 4.8 V.
锟斤拷If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test
normal, replace the ECM.
8. If all circuits/connections test normal, test or replace the Accelerator Pedal Assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.
* Accelerator Pedal Position Sensor Replacement (See: Powertrain Management/Computers and Control Systems/Accelerator Pedal Position
Sensor/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for Engine Control Module replacement,
programming, and setup
P2128
DTC P2120, P2122, P2123, P2125, P2127, P2128, or P2138
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provide an overview of each diagnostic category.
DTC Descriptors
DTC P2120
- Accelerator Pedal Position (APP) Sensor 1 Circuit
DTC P2122
- Accelerator Pedal Position (APP) Sensor 1 Circuit Low Voltage
DTC P2123
- Accelerator Pedal Position (APP) Sensor 1 Circuit High Voltage
