<ul> <li><b>Engine Light ON (or Service Engine Soon Warning Light)</b>: The illumination of the engine light indicates a detected issue with the Input/Turbine Speed Sensor 'B' circuit. This could be due to a malfunctioning sensor, wiring issues, or a problem with the transmission control module.</li> <li><b>Erratic Transmission Shifting</b>: The vehicle may experience irregular or harsh shifting patterns. This symptom is often linked to incorrect or inconsistent readings from the Input/Turbine Speed Sensor 'B'.</li> <li><b>Transmission Slippage</b>: The transmission may slip or fail to engage properly. This can be caused by the sensor providing inaccurate speed data to the transmission control module.</li> <li><b>Reduced Fuel Efficiency</b>: Inaccurate speed sensor readings can lead to improper transmission operation, which may result in decreased fuel efficiency.</li> </ul>

<ul><li>Faulty Input Speed Sensor: The sensor may be malfunctioning, leading to incorrect readings.</li><li>Input Speed Sensor harness is open or shorted: Damaged wiring can disrupt the signal transmission.</li><li>Input Speed Sensor circuit poor electrical connection: Loose or corroded connections can cause intermittent signal loss.</li></ul>

<ul> <li><b>Check Technical Service Bulletins (TSB)</b>: Review TSBs for known issues and fixes related to the P2766 code for your specific vehicle.</li> <li><b>Visual Inspection</b>: Inspect system wiring and connectors for disconnections, corrosion, burns, or shorts. Repair or replace as necessary.</li> <li><b>Battery and Alternator Check</b>: Test the battery and inspect battery cables and ends. Test alternator output to ensure proper charging system function.</li> <li><b>Retrieve and Note Codes</b>: Connect an advanced diagnostic scanner to the diagnostic port, retrieve all stored codes, and note freeze frame data for future reference.</li> <li><b>Data Stream Analysis</b>: Use the scanner data stream to determine which circuit is at fault. Narrow the data stream to include only pertinent information.</li> <li><b>Inspect Sensors for Debris</b>: Check for excessive metal debris on magnetic surfaces of input and/or output speed sensors. Remove excessive debris before reinstallation.</li> <li><b>Inspect Interruption Grooves/Reluctor Wheel</b>: Inspect interruption grooves and/or reluctor wheel notches when sensors are removed.</li> <li><b>Test Sensors with DVOM</b>: Use a DVOM to test individual sensors according to manufacturer’s specifications. Replace sensors that do not comply.</li> <li><b>Check Sensor to Reluctor Clearance</b>: Ensure that sensor to reluctor clearance is within specifications and that mounting surfaces/threaded holes are clear of obstructions.</li> <li><b>Suspect PCM Issues</b>: If all system circuits and sensors are in proper working order, suspect a faulty PCM or a PCM programming error.</li></ul>

<p>The DTC code P2766 indicates an issue with the Input/Turbine Speed Sensor 'B' Circuit Range/Performance. This is a critical issue as it affects the transmission's ability to properly shift gears.</p><ul><li><b>Immediate Actions:</b> Inspect and possibly replace the Input/Turbine Speed Sensor.</li><li><b>Potential Risks:</b> Delayed repair can lead to severe transmission damage and unsafe driving conditions.</li></ul>