P2246
P2246-O2 SENSOR 1/1 REFERENCE VOLTAGE CIRCUIT HIGH
For a complete wiring diagram, refer to the Wiring Information.
Theory of operation
The Oxygen sensors (O2 sensor) are used for fuel control and catalyst monitoring. Each O2 sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Powertrain Control Module (PCM) operates in an Open Loop mode, ignoring the O2 sensor signal voltage while calculating the air-to-fuel ratio. The heating elements inside each O2 sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the PCM to calculate the air-to-fuel ratio sooner. While the engine runs, the O2 sensor heats up and begins to generate a voltage within a range of 0-1,275 mV. Once sufficient O2 sensor voltage fluctuation is observed by the PCM, Closed Loop is entered. The PCM uses the O2 sensor voltage to determine the air-to-fuel ratio. An O2 sensor voltage that increases toward 1,000 mV indicates a rich fuel mixture. An O2 sensor voltage that decreases toward 0 mV indicates a lean fuel mixture.
- When Monitored:
With the ignition on and the O2 Sensor 1/1 at operating temperature.
- Set Condition:
The Powertrain Control Module (PCM) detects a short to voltage on the (K41) O2 Sensor 1/1 Reference Signal circuit for 2.0 seconds.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. DTC IS ACTIVE
1. Ignition on, engine not running.
2. With the scan tool, clear DTCs in the Powertrain Control Module.
3. Start the engine.
4. Allow the engine to reach normal operating temperature.
5. Monitor the scan tool for at least five minutes.
6. With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.
2. CHECK THE (K41) O2 SENSOR 1/1 REFERENCE SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Oxygen Sensor connector.
3. Disconnect the Powertrain Control Module C2 harness connector.
4. Remove the ASD Relay.
5. Connect a jumper wire between cavity 87 and cavity 30 of the ASD Relay Connector.
6. Turn the ignition on.
7. Measure the voltage of the (K41) O2 Sensor Sensor 1/1 Reference Signal circuit at the Oxygen Sensor harness connector.
Is there any voltage present?
Yes
- Repair the (K41) O2 1/1 Reference Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 3
3. OXYGEN SENSOR
1. Turn the ignition off.
2. Reconnect the Powertrain Control Module C2 harness connector.
3. Replace the Oxygen Sensor.
4. Turn the ignition on.
5. With the scan tool, navigate to Miscellaneous Functions and perform the O2 Sensor Replaced procedure.
6. Start the engine.
7. Allow the engine to reach normal operating temperature.
8. Monitor the scan tool for at least five minutes.
9. With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 4
No
- Test Complete.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
4. POWERTRAIN CONTROL MODULE
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor and the Powertrain Control Module.
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace and program the Powertrain Control Module (PCM). Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.