The EOBD/OBDII error code P2100 indicates a problem with the throttle actuator control motor circuit. This article explains the code’s meaning, symptoms, causes, and diagnostic procedures. This issue commonly affects vehicles with electric throttle actuators, particularly Ford and Nissan models.
What is the P2100 Code?
The P2100 code signifies an open circuit in the throttle actuator A control motor. The throttle actuator, typically located on the engine’s front, top, inside the wheel wells, or against the bulkhead, receives electrical signals from the Powertrain Control Module (PCM). The PCM uses inputs from various sensors, such as coolant temperature, intake air temperature, engine RPM, and A/C system pressure, to determine the appropriate throttle position. When the PCM detects an open circuit in the actuator’s control motor, it sets the P2100 code.
Symptoms of a P2100 Code
A P2100 code often results in severe drivability issues due to its impact on engine performance. Because this is usually an electrical fault, the PCM’s ability to compensate is limited. Common symptoms include:
- Illuminated Malfunction Indicator Lamp (MIL): The check engine light will turn on.
- Fixed Idle Speed: The engine may idle at a higher than normal RPM, typically around 1000-1200 RPM.
- Lack of Acceleration: The engine may not respond to accelerator pedal input.
Common Causes of a P2100 Code
Several factors can contribute to a P2100 code:
- Open Circuit in Throttle Actuator Wiring: Damaged or corroded wiring in the throttle actuator circuit is a frequent cause.
- Faulty Throttle Actuator: An internal electrical fault within the throttle actuator itself can lead to an open circuit.
- PCM Failure: While less common, a malfunctioning PCM can also cause this code. Although rare, a faulty PCM can disrupt communication with the throttle actuator.
Diagnosing and Repairing a P2100 Code
Before beginning diagnostic procedures, consult your vehicle’s technical service bulletins (TSBs) for potential known issues and solutions.
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Visual Inspection: Inspect the throttle actuator connector and wiring for damage, such as scraping, rubbing, bare wires, burns, or melted plastic. Clean corroded terminals with electrical contact cleaner and apply dielectric grease.
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Code Clearing: After addressing any visible issues, clear the diagnostic trouble codes using a scan tool and check if the P2100 code returns.
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Actuator and Circuit Testing:
- Resistance Test: Disconnect the throttle actuator harness and measure the resistance across the actuator terminals using a digital multimeter (DVOM). Compare the reading to your vehicle’s specifications. An open or shorted actuator requires replacement.
- Power Supply Test: Check for 12V at the actuator’s power supply circuit using a DVOM. If voltage is absent, diagnose the wiring between the PCM, relay, and actuator.
- Ground Test: Verify a good ground connection at the throttle actuator using a test light. Activate the actuator with a scan tool and observe the test light. A flickering light suggests an intermittent connection.
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PCM Replacement: If all other tests pass, a faulty PCM might be the cause, although this is rare. Replace the PCM only after exhausting all other possibilities. Remember that a new PCM needs programming or calibration.
Conclusion
The EOBD/OBDII error code P2100 indicates a problem within the throttle actuator control motor circuit. This issue can significantly impact vehicle performance. By following the diagnostic steps outlined in this article, you can identify the root cause and implement the necessary repairs to restore proper engine function. If you are uncomfortable performing these diagnostics yourself, consult a qualified automotive technician.
