What the P1109 code means?
For most automakers, a code P1109 will be stored when the wrong manifold air pressure (MAP) sensor voltage reading is detected for a present amount of time, typically four seconds. A vehicle's MAP and BARO sensor work to provide the ECM with information related to the amount or degree of air pressure, or vacuum, that is in the intake manifold at a given point in time. The ECM will then use the data to help calculate the best fuel delivery strategy for the most efficient engine operation.
What causes the P1109 code?
1. Engine Control Module (ECM) outdated or incorrect software.
2. Faulty Engine Control Module (ECM).
What are the symptoms of the P1109 code?
1. Engine Light ON.
2. Engine rough idle.
3. Engine hesitation.
Common mistakes when diagnosing the P1109 code:
It is possible to misdiagnose the cause of a P1109 code to be either the MAP or BARO sensor, when the true problem is related to electrical wiring and circuitry.
What repairs can fix the P1109 code?
1. Replace damaged or corroded, loose, or shorted electrical wiring and related connectors.
2. Repair any mass airflow, manifold air pressure, and engine misfire codes that were also stored.
3. Repair any damage or problems with the MAF circuitry.
4. Repair or replace clogged or damaged filters.
5. Repair damaged or defective air inlet pipe.
6. Clear clogged catalytic converter.
7. Repair vacuum leaks.
8. Replace damaged or defective MAP sensor.
9. Replace damaged or defective BARO sensor.