<ul> <li><b>Engine Light ON (or Service Engine Soon Warning Light)</b>: <b>Engine Light ON</b> indicates a detected issue with the input/turbine speed sensor correlation. This can be caused by <ul><li>faulty input/turbine speed sensors</li><li>damaged wiring or connectors</li><li>issues with the transmission control module (TCM)</li></ul></li> <li><b>Erratic Transmission Shifting</b>: <b>Erratic Transmission Shifting</b> may occur due to incorrect speed sensor readings, leading to improper gear changes. Potential causes include <ul><li>malfunctioning speed sensors</li><li>TCM faults</li><li>electrical issues</li></ul></li> <li><b>Transmission Slipping</b>: <b>Transmission Slipping</b> can result from the TCM receiving inconsistent speed data, causing it to mismanage gear engagement. Possible causes are <ul><li>defective speed sensors</li><li>TCM malfunctions</li><li>wiring problems</li></ul></li> <li><b>Reduced Fuel Efficiency</b>: <b>Reduced Fuel Efficiency</b> may be a symptom due to the transmission not operating optimally, often linked to <ul><li>faulty speed sensors</li><li>incorrect gear ratios</li><li>TCM issues</li></ul></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 between the sensor and the ECU.</li><li>Input Speed Sensor circuit poor electrical connection: Loose or corroded connections can cause intermittent or incorrect sensor signals.</li></ul>

<ul> <li><b>Initial Scan</b>: Use an OBD-II scanner to confirm the presence of DTC P2784 and check for any additional codes.</li> <li><b>Visual Inspection</b>: Inspect the wiring and connectors related to the input/turbine speed sensors for any signs of damage, corrosion, or disconnection.</li> <li><b>Sensor Testing</b>: Test the input/turbine speed sensors 'A' and 'B' using a multimeter to check for proper resistance and voltage readings as per the manufacturer's specifications.</li> <li><b>Connector Check</b>: Ensure that the connectors for the sensors are securely attached and free from any debris or corrosion.</li> <li><b>Signal Verification</b>: Use an oscilloscope to verify the signal output from both sensors while the engine is running to ensure they are producing accurate and consistent signals.</li> <li><b>ECU Inspection</b>: Check the Engine Control Unit (ECU) for any signs of damage or malfunction that could affect the sensor readings.</li> <li><b>Test Drive</b>: Perform a test drive to monitor the sensor readings in real-time and ensure the issue has been resolved.</li> <li><b>Final Scan</b>: Conduct a final OBD-II scan to confirm that the DTC P2784 code has been cleared and no new codes have appeared.</li></ul>

<p>The DTC code P2784 indicates an issue with the correlation between Input/Turbine Speed Sensor 'A' and 'B'. This is a critical issue as it can lead to severe transmission problems.</p><ul><li><b>Immediate Actions:</b> Inspect and possibly replace the speed sensors.</li><li><b>Potential Risks:</b> Delayed repair can result in transmission failure, leading to costly repairs and potential safety hazards.</li></ul>