P1109 - FAULT CODE - OBD2

P1109 ACURA, HONDA: BARO SENSOR CIRCUIT OUT OF HIGH RANGE

The P1109 OBDII fault code is a manufacturer-specific code, and in the case of Acura and Honda, indicates that it is set when the ECM (Engine Control Module) detects that the signal coming from the BARO Sensor (Barometric Pressure Sensor) is not within the expected range.

The BARO sensor provides the Engine Control Module with data about atmospheric pressure, which tends to change according to the altitude driven. This sensor works in conjunction with the Manifold Absolute Pressure sensor (MAP) so that the ECM can determine strategies to increase fuel efficiency, as well as better ignition timing.

• Check Engine light is on.
• The vehicle may remain idle.
• During acceleration, the engine decreases its power.
• Fuel consumption increases.

P1109 OBD2 diagnostic code is set for one or more of the following reasons:

• There may be bad wiring or connectors.
• The BARO Sensor may be defective.
• The MAP Sensor may be damaged.
• The MAF Sensor could be in bad condition.
• TWC (Catalytic Converter) may be clogged.
• ECM could have programming errors or other damage.

The steps to follow to give the respective solution to the DTC P1109 OBDII code are as follows:

• As a first step, you must consult the TSB (Technical Service Bulletins).
• With a scan tool, you should check if there are other error codes configured. If such codes are present and relate to faults specific to the sensors mentioned in this code or misfires, proceed to diagnose those codes.
• Check the wires leading to the BARO Sensor for corrosion damage, wear, or burns. Repair or replace as necessary.
• Verify that the air filters are not clogged. If so, make necessary corrections and replace the filter if necessary.
• Perform voltage checks on the Barometric Pressure Sensor The results you obtain should match those specified by the manufacturer. If there are inconsistencies, check the integrity of the wiring or replace the sensor.