2010 Cadillac CTS Sedan AWD V6-3.6L Page 932
Circuit/System Verification
1. Engine idling at operating temperature for at least 30 seconds. Observe the DTC information, DTCs P0030, P0031, P0032, P0036, P0037,
P0038, P0050, P0051, P0052, P0056, P0057, and P0058 should not set.
2. 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 heated oxygen sensor (HO2S).
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal D and ground.
Note: The ignition circuit supplies voltage to other components. Make sure you test all circuits for a short to ground or test all components
for being shorted that share the ignition circuit.
瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and
the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.
3. Connect a test lamp between the heater control circuit terminal C and B+. The test lamp should not illuminate.
瀚慖f the test lamp is always ON, test the control circuit for a short to ground. If the circuit/connections test normal, replace the ECM.
Note: The control circuit for the HO2S heater is pulled-up to voltage within the ECM, 2.0-3.0 volts on the control circuit is normal.
4. Idle the engine, and verify the test lamp illuminates or flashes.
瀚慖f the test lamp is always OFF, test the control circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.
5. Ignition ON, test for 2.0-3.0 V between the control circuit terminal C and ground.
瀚慖f not within the specified range, test the control circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
6. If all circuits/connections test normal, test or replace the HO2S sensor.
Component Testing
1. Ignition OFF, disconnect the harness connector at the heated oxygen sensor (HO2S) sensor.
2. Test for 5-25 ohm between the terminals C and D of the HO2S.
瀚慖f not within the specified range, replace the HO2S sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen
Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (LLT) (See: Powertrain Management/Computers and
Control Systems/Oxygen Sensor/Service and Repair)
* Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen
Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (LLT) (See: Powertrain Management/Computers and
Control Systems/Oxygen Sensor/Service and Repair)
* Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen
Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (LLT) (See: Powertrain Management/Computers and
Control Systems/Oxygen Sensor/Service and Repair)
* Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen
Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LLT) (See: Powertrain Management/Computers and
Control Systems/Oxygen Sensor/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for engine control module replacement, setup, and
programming
P050A
DTC P0506, P0507, or P050A (Without 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.
