Fix P1220: Throttle Position Sensor A Circuit High Input – Trust iCarsoft CR Eagle

If your check engine light flashes on and you experience reduced power, hesitation during acceleration, or even engine stalling, your diagnostic tool may retrieve P1220. This trouble code points to a critical issue with your vehicle’s Throttle Position Sensor (TPS) or Throttle Control Module—specifically a “Throttle Position Sensor A Circuit High Input” malfunction. The TPS communicates throttle position data to the Engine Control Unit (ECU), and a high input signal disrupts the ECU’s ability to adjust fuel injection and ignition timing. Ignoring P1220 can lead to severe engine performance issues, increased fuel consumption, and potential damage to other components. In this guide, we’ll break down P1220, its causes, and how the iCarsoft CR Eagle—an OE-level diagnostic tool—helps you resolve it efficiently.

What Exactly Is Fault Code P1220?

P1220 is a manufacturer-specific OBD-II trouble code most commonly defined as “Throttle Position Sensor (TPS) A Circuit High Input”. Key details to understand:

• The TPS is a sensor mounted on the throttle body that monitors the position of the throttle plate (open, closed, or partially open) and sends voltage signals to the ECU.
• A “high input” means the ECU detects a voltage signal from the TPS that exceeds the normal operating range (typically 0.5V to 4.5V, depending on the vehicle).
• This indicates a disruption in the TPS circuit—either the sensor is sending an abnormally high signal, or there’s a wiring/connection issue causing false high readings.
• P1220 applies to 1996+ OBD-II compliant vehicles with electronic throttle control systems, including popular makes like Ford, Toyota, Honda, BMW, Mercedes-Benz, and VW.

Why Does P1220 Happen? Common Causes

To fix P1220, identify the root cause first. Here are the most frequent triggers:

• Faulty Throttle Position Sensor (TPS): Internal electrical failure or wear causes the sensor to send consistently high voltage signals.
• Wiring or Connector Issues: Frayed, shorted, or corroded wires, or loose connectors between the TPS and ECU, create a high-resistance circuit.
• Throttle Body Contamination: Carbon buildup on the throttle plate or TPS sensing element interferes with signal accuracy.
• Faulty Throttle Control Module: Malfunction in the module that regulates TPS operation leads to incorrect signal transmission.
• Poor Electrical Ground: A weak or damaged ground connection disrupts the TPS circuit’s voltage stability.
• ECU Malfunction: Rarely, a faulty ECU misinterprets the TPS signal, leading to a false P1220 code.
• Damaged Throttle Linkage: Mechanical issues with the throttle linkage (e.g., binding) force the TPS into an abnormal position.

Symptoms of P1220

P1220 often presents noticeable and disruptive symptoms, including:

• Illuminated check engine light (primary indicator).
• Reduced engine power or “limp mode” (ECU limits power to protect the engine).
• Hesitation or delay when pressing the accelerator.
• Rough idling or engine misfires.
• Increased fuel consumption due to incorrect fuel-air mixture.
• Engine stalling (especially at low speeds or during acceleration).
• Inability to reach normal operating speed.

Why the iCarsoft CR Eagle Is Perfect for P1220

Basic scanners only read P1220, but the iCarsoft CR Eagle offers advanced features that simplify diagnosing and fixing the issue. Here’s why it stands out:

How to Diagnose & Fix P1220 with the iCarsoft CR Eagle (Step-by-Step)

Diagnosing P1220 with the CR Eagle is straightforward, even for beginners:

FAQs About P1220 & the iCarsoft CR Eagle