2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1827
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. Engine idling, command the appropriate B52 HO2S heater to 100 % and 0 % with a scan tool while observing the B52 HO2S Heater Circuit
Test Status parameter. The parameter should display OK or Not Run.
2. Engine idling at operating temperature, observe the scan tool B52 HO2S Heater parameter. The amperage should be within 0.3-1.5 A.
3. Engine idling at operating temperature, move the related wiring and connectors while observing the B52 HO2S Heater parameter with a scan
tool. The parameter should not change with movement.
瀚慖f movement affects the parameter, repair the appropriate harness or connector.
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 appropriate B52 HO2S.
2. Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal D and ground.
瀚慖f the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests
normal and the B52 HO2S heater circuit fuse is open, test all components connected to the fuse and replace as necessary.
3. Probe the appropriate control circuit terminal listed below with a test lamp connected to B+. Verify that the test lamp does not illuminate.
* B52 HO2S 1 terminal E
* B52 HO2S 2 terminal C
瀚慖f the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
4. Engine idling, the test lamp should illuminate, or flash.
瀚慖f the test lamp does not illuminate, or flash, test the control circuit for a short to voltage, or an open/high resistance. If the
circuit/connections test normal, replace the K20 ECM.
Note:
* Less than 10 ohm on the ignition voltage circuit, or control circuit may set a DTC. If there is resistance on a circuit the driver will remain
ON and the scan tool will display greater than 0.00 amp.
* Performing this test may set additional DTCs.
5. Ignition OFF, connect a 10 A fused jumper wire between the control circuit terminal listed below and the ignition voltage circuit terminal D.
* B52 HO2S 1 terminal E
* B52 HO2S 2 terminal C
6. Engine idling, observe the appropriate B52 HO2S Heater parameter. The scan tool should display 0.00 A.
瀚慖f greater than the specified value, test the control circuit and the ignition voltage circuit for high resistance.
7. If all circuits test normal, test or replace the appropriate B52 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 1 Sensor 1 (1500 Series) (See: Powertrain Management/Computers and Control
Systems/Oxygen Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (2500 Series) (See: Powertrain
Management/Computers and Control Systems/Oxygen Sensor/Service and Repair)
* Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (1500 Series) (See: Powertrain Management/Computers and Control
Systems/Oxygen Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (2500 Series) (See: Powertrain
Management/Computers and Control Systems/Oxygen Sensor/Service and Repair)
* 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
