P0109

Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent

Car Fault Codes Fuel & air

Severity Medium Do not ignore it; it may get worse and cost more.
Can you still drive? With care, short trips only
Who can fix it? DIY with some experience
Typical repair time 30 minutes – 2 hours
Typical cost SAR 100 to 600

What it means

The engine computer has seen the manifold absolute pressure (MAP) signal drop out or jump suddenly for short periods and then recover. This usually points to a weak connection in the connector or wiring that reacts to vibration or heat.

Symptoms4

  • Check engine light that comes on and goes off.
  • Sudden jerking or stumbling while driving.
  • Brief stalling at idle.
  • Intermittent hesitation on acceleration.

Possible causes5

  • Loose or corroded pins in the sensor connector.
  • Wire rubbing on metal or cracked internally.
  • Weak shared ground point.
  • Loose sensor hose that disconnects at times, on cars that use one.
  • Intermittent internal sensor failure.

How to diagnose5

  1. Review the freeze frame data to learn when the fault occurred.
  2. Watch the sensor signal on a scan tool while gently moving the harness and connector, looking for sudden jumps.
  3. Inspect the connector pins and how tightly they grip.
  4. Trace the harness for rubbing points.
  5. Check the sensor hose and how well it is secured.

How to fix6

  1. Clean and tighten the connector pins, or replace the connector.
  2. Repair the chafed section of the harness and secure it.
  3. Clean and retighten the ground point.
  4. Secure or replace the sensor hose.
  5. Replace the sensor if its signal still jumps with good wiring.
  6. Clear the codes and road test under conditions similar to when the fault appeared.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The fix is often a low-cost connector or wire repair; the cost rises if the sensor must be replaced or tracing the fault takes a long time.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Why is this code hard to diagnose?

Because the fault is not present all the time, so the technician must watch the signal while moving the wiring or drive under the conditions when it appeared.

Can I ignore the code if it goes away?

It is not recommended, because a weak connection gets worse over time and can become a constant fault that causes stumbling or stalling.

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This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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