The P2621: Throttle Position Output Circuit Low code indicates that the voltage in the throttle position output circuit is below the expected level. This problem could affect the throttle position sensor’s ability to accurately relay the position of the throttle to the engine control module (ECM), potentially leading to poor performance, hesitation, or difficulty in maintaining consistent speed.
P2621 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P2621: Throttle Position Output Circuit Low |
| Is it serious? | Yes, as low voltage in the throttle position circuit can lead to incorrect throttle control, resulting in poor engine performance, hesitation, or stalling. |
| Possible causes | – Low voltage supply to the throttle position sensor – Faulty throttle position sensor – Wiring or connector issues |
| How to diagnose? | – Measure voltage in the throttle position output circuit – Test the throttle position sensor for proper function – Check wiring and connectors – Replace faulty components if needed |
P2621 Meaning
The P2621: Throttle Position Output Circuit Low code means that the throttle position sensor (TPS) is receiving a lower than expected voltage. The TPS provides crucial information about the position of the throttle to help the ECM manage fuel injection and ignition timing. A low voltage signal can result from issues such as a faulty sensor, poor electrical connections, or degraded wiring, all of which can lead to inconsistent throttle response, hesitation, or decreased engine performance.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to determine if there are any other related codes present. Addressing additional codes may help provide further context to the issue. | OBD-II Scanner |
| Measure Voltage in Throttle Position Circuit | Use a multimeter to measure the voltage being supplied to the throttle position sensor. Compare the voltage reading to manufacturer specifications to determine if it falls below the required range. | Multimeter, Diagnostic Tool |
| Test Throttle Position Sensor | Test the throttle position sensor by monitoring its output signal while moving the throttle. Verify that the output changes smoothly and is within the expected range. | Multimeter, Diagnostic Tool |
| Inspect Wiring and Connectors | Inspect the wiring and connectors for any signs of damage, corrosion, loose connections, or shorts. Repair or replace damaged components as necessary. | Flashlight, Multimeter |
| Check Sensor Mounting | Ensure that the throttle position sensor is securely mounted. A loose sensor may cause incorrect or inconsistent readings, resulting in a low voltage signal. | Flashlight, Safety Gloves |
| Replace Faulty Components | Replace any faulty components, such as the throttle position sensor or damaged wiring. Ensure that replacement parts meet manufacturer specifications. | Replacement Parts |
| Clear the Code and Test Drive | After completing repairs, use an OBD-II scanner to clear the P2621 code. Start the engine and perform a test drive to monitor throttle response and verify that the issue has been resolved. | OBD-II Scanner, Vehicle Owner’s Manual |
| Recheck for Codes | Re-scan the vehicle to confirm that the P2621 code has been cleared. If the code returns, further diagnostics may be required to locate other underlying issues. | OBD-II Scanner |
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