The EOBD/OBDII error code P1516 often indicates an issue with the throttle position sensor or its related circuitry. This code can trigger a “Reduced Power Mode” to prevent potential runaway situations. This article outlines diagnostic steps to help pinpoint the cause of the P1516 code.
Diagnosing the P1516 Code: A Step-by-Step Guide
Begin by inspecting the throttle body harness connector. Disconnect the connector and gently tug on individual wires to check for looseness. Visually examine the wiring along the connector pigtail for any signs of damage, such as cuts, separations, or aftermarket wiring connections (e.g., alarms, remote starters).
Next, use an electrical circuit spray solvent to clean both the throttle body connector insert and the harness connector. Allow them to dry completely before reconnecting.
With the engine idling, carefully manipulate the harness-pigtail wiring. Observe if the engine shudders or reacts to these movements. Any response suggests a possible loose or broken wire within the harness.
Connect an OBD2 scanner and monitor the ACC pedal’s high and low voltage PIDs (Parameter IDs). With the ignition key in the “On-Run” position (engine off), repeatedly depress and release the accelerator pedal while observing the voltage readings on the OBD2 scanner. Record the voltage fluctuations for both the high and low circuits. These readings can provide valuable insights into potential issues with the accelerator pedal module or the throttle body.
Common Causes of the P1516 Code
The P1516 code often points to a problem within the throttle body connector, harness pigtail, or the accelerator pedal module itself. In some cases, a faulty throttle position sensor within the throttle body might be the culprit, requiring replacement.
Why “Reduced Power Mode”?
The vehicle’s Powertrain Control Module (PCM) activates “Reduced Power Mode” as a safety precaution when it detects a potential issue that could lead to unintended wide-open throttle scenarios. By reducing engine power, typically by disabling one or more cylinders, the PCM prevents potential accidents. This mode is triggered by various conditions, including the P1516 code.
Conclusion
Diagnosing the Eobd/obdii P1516 code requires a systematic approach involving visual inspection, connector cleaning, and monitoring voltage readings with an OBD2 scanner. By following these steps, you can effectively narrow down the potential causes and address the underlying issue, restoring your vehicle’s performance and ensuring safe operation.
