2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2856
7. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P2120 or P2125 are the only DTCs set.
瀚慖f DTC P2120 or P2125 are the only DTCs set, replace the ECM.
8. 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 accelerator pedal.
2. Ignition OFF for 2 minutes and the scan tool powered OFF, test for less than 5 ohm between the appropriate low reference circuit terminal
listed below and ground.
* APP sensor 1 terminal F
* APP sensor 2 terminal A
瀚慖f 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-volt reference circuit terminal listed below and ground.
* APP sensor 1 terminal D
* APP sensor 2 terminal C
瀚慖f less than the specified range, test the 5-volt reference circuit for an open/high resistance or short to ground. If the circuit tests normal,
replace the ECM.
瀚慖f greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Verify the scan tool APP sensor 1 and 2 voltages are less than 0.3 V.
瀚慖f greater than the specified range, test the APP sensor 1 and 2 signal circuits terminals B and E for a short to voltage. If the circuit tests
normal, replace the ECM.
5. Install a 3 A fused jumper wire between the APP sensor 1 signal circuit terminal E and the 5-volt reference circuit terminal D. Verify the scan
tool APP sensor 1 voltage parameter is greater than 4.8 V.
瀚慖f less than the specified range, test the APP sensor 1 signal circuit for a short to ground or an open/high resistance. If the circuit tests
normal, replace the ECM.
6. Install a 3 A fused jumper wire between the APP sensor 2 signal circuit terminal B and the 5-volt reference circuit terminal D. Verify the scan
tool APP sensor 2 voltage parameter is greater than 4.8 V.
瀚慖f less than the specified range, test the APP sensor 2 signal circuit for an open/high resistance or short to ground. If the circuit tests
normal, replace the ECM.
7. If all circuits and connections test normal, test or replace the Accelerator Pedal Position Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* 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 ECM replacement, setup, and programming
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.
