2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2883
than 200 mV when the throttle is quickly cycled 3 times from closed to wide open and back to closed after running the engine at 1,500 RPM
for 30 seconds.
6. 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
Note: All modules must be powered down or misdiagnosis may result.
1. Ignition OFF, disconnect the scan tool and wait 60 seconds to ensure all modules are powered down.
2. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
3. Test for less than 5 ohm between the low reference circuit terminal A and ground.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
4. Ignition ON, verify the appropriate scan tool HO2S parameter is approximately 450 mV.
瀚慖f less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
瀚慖f greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool HO2S parameter is less
than 60 mV.
瀚慖f greater than the specified range, test the signal circuit for an open/high resistance. If the circuits test normal, replace the ECM.
6. Verify none of the following conditions exist:
* Rich fuel injectors-Refer to Fuel Injector Diagnosis (CH47976) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel
Injector/Testing and Inspection)Fuel Injector Diagnosis (J39021 or Scan Tool) (See: Powertrain Management/Fuel Delivery and Air
Induction/Fuel Injector/Testing and Inspection)
* Water intrusion in the HO2S harness connector
* High fuel system pressure-Refer to Fuel System Diagnosis (w/o FPCM) (See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Component Tests and General Diagnostics)Fuel System Diagnosis (FPCM) (See: Powertrain
Management/Computers and Control Systems/Testing and Inspection/Component Tests and General Diagnostics)
* Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool) (See: Powertrain
Management/Computers and Control Systems/Testing and Inspection/Component Tests and General
Diagnostics/Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool))Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool) (
See: Powertrain Management/Fuel Delivery and Air Induction/Fuel/Testing and Inspection/Alcohol/Contaminants-in-Fuel Diagnosis
(Special Tool))
* Fuel saturation of the evaporative emission (EVAP) canister
瀚慖f you find any of the above conditions, repair as necessary.
7. If all circuits test normal, replace the appropriate HO2S.
Repair Instructions
Caution: Refer to Heated Oxygen Sensor Resistance Learn Reset Caution (See: Powertrain Management/Computers and Control
Systems/Oxygen Sensor/Service Precautions/Heated Oxygen Sensor Resistance Learn Reset Caution).
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (1500 Series) (See: Powertrain Management/Computers and Control
Systems/Oxygen Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (2500 Series) (See: Powertrain
Management/Computers and Control Systems/Oxygen Sensor/Service and Repair)
* Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (1500 Series) (See: Powertrain Management/Computers and Control
Systems/Oxygen Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (2500 Series) (See: Powertrain
Management/Computers and Control Systems/Oxygen Sensor/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
P2272
DTC P2270 or P2272
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.
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