P1129 Honda Code - Manifold Absolute Pressure Sensor Circuit Higher Than Expected

Quick Answer

When a P1129 code appears in a Honda vehicle, it indicates that the Manifold Absolute Pressure (MAP) sensor circuit is reading a higher pressure than expected by the Engine Control Module (ECM). Common causes include Faulty MAP sensor, Wiring or connector issues in the MAP sensor circuit, Vacuum leaks in the intake manifold. 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

P1129 Honda indicates Manifold Absolute Pressure Sensor Circuit Higher Than Expected.

Common causes

Common causes include Faulty MAP sensor, Wiring or connector issues in the MAP sensor circuit, Vacuum leaks in the intake manifold.

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.

• Description
• Common Causes
• Symptoms
• How To Fix
• Cost to Fix
• Tech Notes
• FAQs
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Common Causes of P1129 Honda

Symptoms of P1129 Honda

How to Fix P1129 Honda

Cost to Fix P1129 Honda

Tech Notes for P1129 Honda

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Information for Specific Honda Models

• P1129 2008 Honda Accord — Manifold Absolute Pressure Sensor Circuit Higher Than Expected
• P1129 2009 Honda Accord — Manifold Absolute Pressure Sensor Circuit Higher Than Expected
• P1129 2010 Honda Accord — Manifold Absolute Pressure Sensor Circuit Higher Than Expected
• P1129 1996 Honda Civic — Manifold Absolute Pressure Sensor Circuit Higher Than Expected
• P1129 1997 Honda Civic — Manifold Absolute Pressure Sensor Circuit Higher Than Expected
• P1129 1998 Honda Civic — Manifold Absolute Pressure Sensor Circuit Higher Than Expected
• P1129 1999 Honda Civic — Manifold Absolute Pressure Sensor Circuit Higher Than Expected
• P1129 2000 Honda Civic — Manifold Absolute Pressure Sensor Circuit Higher Than Expected

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1129 Honda Code

1. What are common symptoms of OBDII code P1129 in a Honda?

- Common symptoms include rough idling, poor acceleration, engine stalling, and a decrease in fuel efficiency.

2. What causes the OBDII code P1129 in a Honda related to the Manifold Absolute Pressure (MAP) sensor circuit?

- The code is typically triggered when the MAP sensor circuit reports a pressure reading that is higher than expected by the engine control module.

3. How can I diagnose the OBDII code P1129 in my Honda?

- Diagnosing the issue involves checking the MAP sensor and its wiring for any faults or damages. Additionally, inspect the vacuum lines for leaks.

4. Can a dirty or faulty MAP sensor cause the OBDII code P1129 in a Honda?

- Yes, a dirty or faulty MAP sensor can send incorrect pressure readings to the engine control module, triggering the code.

5. What are some repair tips for addressing the OBDII code P1129 in a Honda?

- Start by cleaning the MAP sensor and checking the wiring connections. If the issue persists, consider replacing the MAP sensor.

6. Is it safe to continue driving with the OBDII code P1129 in a Honda?

- It is not recommended to continue driving with this code, as it can lead to further engine performance issues and potential damage if left unresolved.

7. Can a vacuum leak be a possible cause of the OBDII code P1129 in a Honda?

- Yes, a vacuum leak can disrupt the pressure readings received by the MAP sensor, potentially causing the code to trigger.

8. How do I reset the OBDII code P1129 in my Honda after making repairs?

- You can reset the code using an OBDII scanner or by disconnecting the car battery for a few minutes to clear the error code.

9. Are there any specific Honda models known to be prone to experiencing the OBDII code P1129?

- While the code can occur in various Honda models, some vehicles equipped with MAP sensors may be more susceptible to triggering the P1129 code.

10. Can a damaged or disconnected MAP sensor connector cause the OBDII code P1129 in a Honda?

- Yes, a damaged or disconnected MAP sensor connector can disrupt the sensor's communication with the engine control module, leading to the code.