Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.

NOTE:
After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors.
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
  WARNING:
  When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
3. With the scan tool, read DTCs and record on the repair order.
  NOTE:
  It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.
  
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECKING THE EXHAUST SYSTEM FOR LEAKS
1. Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS .
  Were any exhaust leaks found?
  
  Yes
  - Repair or replace the leaking exhaust parts as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE O2 SENSOR VOLTAGE READINGS
NOTE:
This DTC will set due to poor engine performance as well as a faulty O2 Sensor. If the vehicle exhibits any fuel system or driveability issues, or has any other driveability DTCs present, repair those concerns before proceeding with this test.

NOTE:
If the Powertrain Control Module detects an active open or short on any of the O2 Sensor 1/1 circuits, it will power down all of the O2 Sensor circuits to protect the O2 Sensor PCM internal ASIC from being damaged.
1. Back probe the O2 Sensor 1/1 connector, measure the voltages at the (K41) O2 Sensor Signal circuit and the (K902) O2 Sensor Return circuit at the Wide-band O2 Sensor connector.
  NOTE:
  The (K902) O2 Sensor 1/1 Return circuit voltage should read approximately 3.8 volts and the (K41) O2 Sensor 1/1 Signal circuit should read between approximately 3.35 volts and 4.25 volts if operating normally with no opens or shorts.
  
  Do the circuit voltages read as described?
  
  Yes
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
  No
  - Go To 4
CHECK THE O2 SENSOR 1/1 CIRCUITS FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the O2 Sensor 1/1 harness connector.
3. Turn the ignition on.
4. Measure for voltage at the:
  - (K41) O2 Sensor 1/1 Signal circuit at the O2 Sensor 1/1 harness connector.
  - (K902) O2 Sensor 1/1 Return circuit at the O2 Sensor 1/1 harness connector.
  - (K89) O2 Sensor 1/1 Current Pump circuit at the O2 Sensor 1/1 harness connector.
  Do any of the circuits measure above 0.5 volts?
  
  Yes
  - Repair the circuit that measured above 0.5 volts for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK THE O2 SENSOR 1/1 CIRCUITS FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Check for continuity between ground and the:
  - (K41) O2 Sensor 1/1 Signal circuit at the O2 Sensor 1/1 harness connector.
  - (K902) O2 Sensor 1/1 Return circuit at the O2 Sensor 1/1 harness connector.
  - (K89) O2 Sensor 1/1 Current Pump circuit at the O2 Sensor 1/1 harness connector.
  Is there continuity between any of the above circuits and ground?
  
  Yes
  - Repair the circuit that measured above below 10k Ohms for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
CHECK THE O2 SENSOR 1/1 CIRCUITS FOR AN OPEN OR HIGH RESISTANCE
CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
1. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
2. Measure the resistance of the:
  - (K41) O2 Sensor 1/1 Signal circuit between the O2 Sensor 1/1 harness connector and the GPEC Adaptor.
  - (K902) O2 Sensor 1/1 Return circuit between the O2 Sensor 1/1 harness connector and the GPEC Adaptor.
  - (K89) O2 Sensor 1/1 Current Pump circuit between the O2 Sensor 1/1 harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms? for each of the above circuits?
  
  Yes
  - Go To 7
  No
  - Repair the circuit that measured above 3.0 Ohms for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
O2 SENSOR
NOTE:
Check for signs of contaminants that may have damaged the O2 Sensor, such as contaminated fuel, unapproved silicone, oil and coolant.
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 and the Powertrain Control Module (PCM).
  - Look for any chafed, pierced, pinched, or partially broken wires.
  - Look for broken, bent, pushed out or corroded terminals.
  - Verify that there is good pin to terminal contact in the O2 Sensor 1/1 and Powertrain Control Module connectors.
  - Perform any Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the Oxygen Sensor in accordance with the Service Information. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .