P1108 - FAULT CODE - OBD2
Description of DTC code P1108 Generic
The P1108 OBDII fault code is powertrain-related and is manufacturer specific, which indicates an engine air and fuel metering problem. Basically, this code indicates that the Engine Control Module (ECM) has detected a fault in the Barometric Pressure Sensor (BARO) due to a voltage signal that is above the expected level. However, this code can also be set due to a failure of the MAP sensor (Manifold Absolute Pressure).
The BARO sensor provides information on atmospheric pressure, which varies depending on the vehicle’s altitude. The MAP sensor is used in the engine’s electronic control system. The information transmitted by the MAP sensor indicates the pressure in the intake manifold, and with this data, the air density is calculated and the engine’s air mass flow rate is determined. Both the MAP and BARO sensors work together in order for the ECM to determine strategies for better fuel utilization and ignition timing. If one of these sensors sends a voltage signal that exceeds the manufacturer’s allowable limit, the P1108 code will be set.
Symptoms of fault code P1108 Generic
- Check Engine lamp comes on.
- Instabilities in engine operation.
- During acceleration or idling the engine stumbles.
- Increased fuel consumption.
Causes of OBD2 P1108 Generic
The reasons for setting the P1108 OBD2 diagnostic code are as follows:
- Bad wiring or connectors may be present in the MAP Sensor or BARO Sensor
- The Manifold Absolute Pressure Sensor may be damaged.
- The barometric pressure sensor may be defective.
- There may be a programming error in the Engine Control Module.
Possible solutions of the DTC code P1108 Generic
To troubleshoot DTC P1108 OBDII you must do the following:
- To begin with, consult the TSBs. These are useful at the time of diagnosis. In addition, you need to check for other error codes, paying particular attention to misfires or those related to the MAF or MAP Sensor.
- Check all connectors and respective wires that are related to the MAP Sensor and BARO Sensor for obvious damage. If necessary, make repairs or replacements.
- Follow the diagnostic steps regarding the Barometric Pressure Sensor and Manifold Absolute Pressure Sensor. If you find defects in these, proceed to make the necessary corrections.
- Verify that the electrical values of the sensors related to this code match those specified and if you find large differences, make the necessary repairs.