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P1129 2000 Honda Civic Code - Manifold Absolute Pressure Sensor Circuit Higher Than Expected

Quick Answer

The P1129 code in a 2000 Honda Civic indicates that the Manifold Absolute Pressure (MAP) sensor circuit is reading a pressure that is higher than expected by the Engine Control Module (ECM). Common causes include Faulty MAP sensor, Wiring issue in the sensor circuit, Vacuum leak 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 2000 Honda Civic indicates Manifold Absolute Pressure Sensor Circuit Higher Than Expected.
Common causes
Common causes include Faulty MAP sensor, Wiring issue in the sensor circuit, Vacuum leak 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.
What is this?
Table of contents Created and updated by William Orellana on Sep 12, 2024
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Code P1129 2000 Honda Civic Description

The P1129 code in a 2000 Honda Civic indicates that the Manifold Absolute Pressure (MAP) sensor circuit is reading a pressure that is higher than expected by the Engine Control Module (ECM). The MAP sensor plays a crucial role in the engine's operation by measuring the pressure inside the intake manifold and providing this information to the ECM. The ECM uses this data to calculate the air-fuel mixture needed for efficient combustion. When the MAP sensor circuit reads a pressure that is higher than expected, it can lead to several performance issues in the vehicle.

OBDII Code P1129 2000 Honda Civic - Manifold Absolute Pressure Sensor Circuit Higher Than Expected
P1129 2000 Honda Civic Code - Manifold Absolute Pressure Sensor Circuit Higher Than Expected

Common Causes of P1129 2000 Honda Civic

  1. Faulty MAP sensor
  2. Wiring issue in the sensor circuit
  3. Vacuum leak in the intake manifold
  4. Clogged air filter
  5. ECM malfunction

Symptoms of P1129 2000 Honda Civic

  1. Decreased engine power and acceleration
  2. Rough idling or stalling
  3. Poor fuel efficiency
  4. Increased emissions

How to Fix P1129 2000 Honda Civic

  1. Begin by inspecting the MAP sensor and its wiring for any visible damage or corrosion. Replace the sensor if necessary.
  2. Check for any vacuum leaks in the intake manifold by performing a smoke test or using a vacuum gauge. Repair any leaks found.
  3. Inspect the air filter for any clogs or restrictions and replace if needed.
  4. Clear the diagnostic trouble codes from the ECM using a scan tool and test drive the vehicle to ensure the issue has been resolved.

Cost to Fix P1129 2000 Honda Civic

The typical repair costs for addressing the P1129 code in a 2000 Honda Civic can range from $100 to $300, depending on the specific cause of the issue and the cost of parts and labor in your area. It's important to note that diagnosis time and labor rates at auto repair shops can vary, so it's recommended to check with local shops for a more accurate estimate. Keep in mind that rates may be higher at dealerships or in metropolitan areas, while independent shops may offer more competitive pricing.

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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 2000 Honda Civic Code

1. What does the OBDII code P1129 on a 2000 Honda Civic indicate?

The P1129 code in a 2000 Honda Civic indicates that the Manifold Absolute Pressure (MAP) Sensor Circuit has registered a voltage higher than expected, suggesting a potential issue with the MAP sensor or its circuit.

2. What are common symptoms of the P1129 code in a 2000 Honda Civic?

Common symptoms include engine misfiring, hesitation during acceleration, rough idling, decreased fuel efficiency, and the check engine light being illuminated.

3. What could cause the P1129 code to appear on a 2000 Honda Civic?

Potential causes include a faulty MAP sensor, electrical issues like shorted or frayed wiring, vacuum leaks, or a problem with the Engine Control Module (ECM).

4. How can I troubleshoot the P1129 code in a 2000 Honda Civic?

Start by visually inspecting the MAP sensor and its connections for any obvious signs of damage or disconnection. Check the wiring for shorts or corrosion, and test the sensor's voltage with a multimeter to ensure it aligns with manufacturer specifications.

5. What steps should be taken to fix the P1129 code on a 2000 Honda Civic?

Depending on the identified issue, repairs may involve replacing the MAP sensor, repairing or replacing damaged wiring or connectors, fixing any vacuum leaks, or in some cases, reprogramming or replacing the ECM.

6. Is it safe to drive a 2000 Honda Civic with a P1129 code?

While you may be able to drive with this code, doing so can lead to reduced performance and fuel efficiency. Continuous driving with this issue can potentially lead to further engine damage, so it is advisable to address the problem promptly.

7. What tools are required to diagnose the P1129 code on a 2000 Honda Civic?

Tools needed include a digital multimeter for testing sensor voltages and continuity, a scan tool to read and clear the code, and possibly a vacuum gauge to check for leaks in the intake manifold.

8. Can a faulty MAP sensor affect the overall performance of a 2000 Honda Civic?

Yes, a faulty MAP sensor can significantly affect the engine's performance. It can alter fuel delivery and ignition timing, leading to issues like stalling, hesitation, and reduced fuel economy.

9. How often does the MAP sensor need to be replaced in a 2000 Honda Civic?

The MAP sensor doesn't have a specific replacement interval, but it should be replaced if diagnostic testing confirms it is faulty or if it is physically damaged. Regular checks during routine maintenance can help catch issues early.

10. What preventive measures can be taken to avoid the P1129 code in a 2000 Honda Civic?

Regular maintenance checks including inspecting the MAP sensor and associated wiring, keeping the engine and its components clean, and addressing any engine performance issues promptly can help prevent this code from appearing.

Discuss the causes and fixes for P1129 2000 Honda Civic OBDII Code

Submit a New Comment

  • my 02 Honda 1.7 timing belt broke off 5 teeth on the timing belt then it bent intake valves. So i replaced the bent valves and put my head back on. went to start the motor and it is rough running and when i push the gas peddle it didn't have power and code p1129 came on . still runs rough and i don't know if i should put a new map sensor . Need help

    Reply to Comment

  • Yes you should start by replacing the sensor. Bad sensor could cause the engine to run rough.

    Reply to Comment