P1121 Honda Code - Throttle Position Lower Than Expected
Quick Answer
The P1121 diagnostic trouble code (DTC) for Honda vehicles indicates that the throttle position sensor (TPS) is reporting a lower voltage signal than expected by the engine control module (ECM). Common causes include Faulty throttle position sensor, Wiring issues or corrosion in the TPS circuit, Malfunctioning ECM. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1121 Honda indicates Throttle Position Lower Than Expected.
- Common causes
- Common causes include Faulty throttle position sensor, Wiring issues or corrosion in the TPS circuit, Malfunctioning ECM.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P1121 Honda Description
The P1121 diagnostic trouble code (DTC) for Honda vehicles indicates that the throttle position sensor (TPS) is reporting a lower voltage signal than expected by the engine control module (ECM). The throttle position sensor is a crucial component of the electronic throttle control system, as it informs the ECM about the position of the throttle plate. This information is essential for the ECM to calculate the appropriate air-fuel mixture and adjust the engine's performance accordingly.
Common Causes of P1121 Honda
- Faulty throttle position sensor
- Wiring issues or corrosion in the TPS circuit
- Malfunctioning ECM
- Mechanical problems with the throttle body
Symptoms of P1121 Honda
- Poor acceleration
- Hesitation or stumbling during acceleration
- Rough idling
- Stalling
- Reduced fuel efficiency
How to Fix P1121 Honda
- Begin by diagnosing the specific cause of the P1121 code using a diagnostic scanner to read the TPS voltage signal and inspecting the throttle position sensor and wiring for any visible damage.
- If the throttle position sensor is faulty, replace it with a new OEM or high-quality aftermarket sensor.
- Check and repair any damaged wiring or connectors in the TPS circuit to ensure proper signal transmission.
- If the ECM is found to be malfunctioning, consider reprogramming or replacing it as necessary.
- Finally, clear the DTC and test drive the vehicle to ensure that the issue has been resolved.
Cost to Fix P1121 Honda
The typical repair costs for addressing a P1121 code in a Honda vehicle can range from $100 to $300, depending on the specific cause of the issue and the cost of parts and labor. It's important to note that the actual repair costs can vary based on factors such as the location of the repair shop, the vehicle's make and model, and the engine type. Additionally, the diagnosis time and labor rates at auto repair shops can also influence the overall repair costs. It's recommended to obtain quotes from multiple repair shops to get a more accurate estimate for addressing the P1121 code.
Need more information about the P1121 Honda code?
Need more information on how to fix the P1121 Honda code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P1121 Honda code diagnosed by a professional: Find a repair shop in your area
Information for Specific Honda Models
- P1121 1996 Honda Civic — Throttle Position Lower Than Expected
- P1121 1997 Honda Civic — Throttle Position Lower Than Expected
- P1121 1998 Honda Civic — Throttle Position Lower Than Expected
- P1121 1999 Honda Civic — Throttle Position Lower Than Expected
- P1121 2000 Honda Civic — Throttle Position Lower Than Expected
Frequently Asked Questions about P1121 Honda Code
No Frequently Asked Questions about P1121 Honda Code found.
Discuss the causes and fixes for P1121 Honda OBDII Code
Code P1121 Honda comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.