2010 Cadillac CTS Sedan AWD V6-3.0L Page 1836
3. Ignition ON, test for 4.8-5.2 V between both 5-volt reference circuit terminals listed below and ground.
* 5 volt reference circuit terminal C
* 5 volt reference circuit terminal F
瀚慖f less than the specified range, test the appropriate 5-volt reference circuit for a short to ground or open/high resistance. 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 appropriate APP sensor voltage parameter is at 0 V.
瀚慖f greater than the specified range, test the appropriate signal circuit terminal listed below for a short to voltage. If the circuit tests normal,
replace the ECM.
* APP sensor 1 signal circuit terminal E
* APP sensor 2 signal circuit terminal B
5. Install a 3 A fused jumper wire between the appropriate signal circuit listed below and the 5-volt reference circuit terminal C. Verify the
appropriate APP sensor voltage parameter is greater than 4.8 V.
* APP sensor 1 signal circuit terminal E
* APP sensor 2 signal circuit terminal B
瀚慖f 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 ECM.
6. If all circuits test normal, replace the accelerator pedal assembly.
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
P2127
DTC P2122, P2123, P2127, P2128, or P2138 (LF1)
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) provides an overview of each diagnostic category.
DTC Descriptors
DTC P2122
- Accelerator Pedal Position (APP) Sensor 1 Circuit Low Voltage
DTC P2123
- Accelerator Pedal Position (APP) Sensor 1 Circuit High Voltage
DTC P2127
- Accelerator Pedal Position (APP) Sensor 2 Circuit Low Voltage
DTC P2128
- Accelerator Pedal Position (APP) Sensor 2 Circuit High Voltage
DTC P2138
- Accelerator Pedal Position (APP) Sensor 1-2 Correlation
Diagnostic Fault Information
