<ul> <li><b>Engine Light ON (or Service Engine Soon Warning Light)</b>: <b>Engine Light ON</b> indicates a problem with the O2 Sensor Reference Voltage Circuit Low in Bank 2 Sensor 1. This can be caused by a faulty O2 sensor, damaged wiring, or a malfunctioning Engine Control Module (ECM).</li> <li><b>Poor Fuel Economy</b>: <b>Poor Fuel Economy</b> may occur due to incorrect air-fuel mixture readings from the O2 sensor, leading to inefficient combustion.</li> <li><b>Rough Idle</b>: <b>Rough Idle</b> can result from improper air-fuel ratio adjustments caused by the faulty O2 sensor, affecting engine performance.</li> <li><b>Increased Emissions</b>: <b>Increased Emissions</b> may be observed due to the engine running either too rich or too lean, as the ECM receives incorrect data from the O2 sensor.</li> </ul>

<ul><li>The front oxygen sensor on Bank 2 may be faulty, leading to incorrect voltage readings.</li><li>An open or shorted harness in the front oxygen sensor Bank 2 can disrupt the reference voltage circuit.</li><li>Poor electrical connections in the front oxygen sensor Bank 2 circuit can cause low voltage issues.</li></ul>

<ul> <li><b>Retrieve and Record Codes</b>: Connect the diagnostic scanner to the vehicle's diagnostic port. Retrieve all stored codes and pertinent freeze frame data. Write down the information for reference.</li> <li><b>Clear Codes and Test Drive</b>: Clear the codes and test drive the vehicle until the code is restored or the PCM enters readiness mode. If the code is restored, proceed with the diagnosis.</li> <li><b>Perform Visual Inspection</b>: Inspect related wiring and connectors for damage. Repair or replace any cut, burned, or damaged wiring.</li> <li><b>Test O2 Sensor Voltage</b>: Use a DVOM to test the O2 sensor voltage at the appropriate connector pin near the sensor. If no voltage is detected, check system fuses and replace any blown or defective fuses.</li> <li><b>Check PCM Connector Voltage</b>: Test the corresponding circuit at the PCM connector. If no voltage is detected, suspect an open circuit between the sensor and the PCM. If voltage is detected, suspect a defective PCM or PCM programming error.</li> <li><b>Test O2 Sensor Functionality</b>: Start the engine and allow it to reach normal operating temperature. Observe oxygen sensor input data on the scanner. Pre-cat sensors should cycle between 1 and 900 millivolts. Post-cat sensors should also cycle but remain relatively stable. Replace any sensors that fail to cycle adequately.</li> <li><b>Consult Technical Service Bulletins (TSB)</b>: Search for TSBs that replicate the code, vehicle, and symptoms. This may provide a speedy solution to the diagnosis.</li></ul>

<p>The DTC code P2249 indicates a low reference voltage in the O2 sensor circuit for Bank 2 Sensor 1. This can lead to incorrect air-fuel mixture readings, affecting engine performance and fuel efficiency.</p><ul><li><b>Immediate Actions:</b> Inspect the O2 sensor wiring and connectors for damage or corrosion.</li><li>Check the sensor's reference voltage with a multimeter.</li><li>Replace the O2 sensor if necessary.</li></ul><p>Delaying repair can result in increased emissions and potential damage to the catalytic converter.</p>