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Information only. This page provides general educational information about fault code P1129. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.

Recommended next steps

Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.

What does P1129 mean?

P1129 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Manifold Absolute Pressure (MAP) Sensor Signal Higher Than Expected.

Manufacturer-specific notes

Some manufacturers publish additional definitions or variations for this code. Always cross-check with your vehicle's own service documentation.

Acura Manifold Absolute Pressure (MAP) Sensor Signal Higher Than Expected
BMW Engine Oil Level Sensor Signal Oil Level Too Low
Ford Downstream Oxygen Sensors Swapped From Bank-to-Bank
Honda Manifold Absolute Pressure (MAP) Sensor Signal Higher Than Expected
Jaguar Manifold Absolute Pressure (MAP) Sensor Signal Higher Than Expected
Land Rover Manifold Absolute Pressure (MAP) Sensor Signal Higher Than Expected
MINI Manifold Absolute Pressure (MAP) Sensor Signal Higher Than Expected
Mazda HO2S-12 (Bank 1 Sensor 2) Signals Swapped (Self-Test)
Volvo Manifold Absolute Pressure (MAP) Sensor Signal Higher Than Expected

About Oil System codes

Oil system codes monitor engine oil quality, level, or pressure. Some are sensor-driven (oil quality monitors) and largely cosmetic; others (oil pressure low) are critical and indicate stop-driving-now conditions.

P1129 is one of 123 codes in this category. Browse all Oil System codes →

What we know about P1129 specifically

We record the SAE J2012 standardised definition and the system this code belongs to, but we have not yet published detailed driver-reported symptoms, common causes, or step-by-step diagnostic guidance for P1129.

Rather than invent that information by generating generic content from a template, we leave it out. For specific guidance, the most reliable sources are:

  • your vehicle's own service manual or manufacturer-specific technical bulletins
  • a qualified mechanic with a manufacturer-level diagnostic tool
  • a marque specialist familiar with your make and model

Spotted an issue or have something to add? Mechanics, technicians, and drivers who have first-hand experience with P1129 can submit a correction or expansion. We review every submission before publishing, mechanic submissions are prioritised.

Information only, not professional advice

The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →

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