Automotive DIY:Barometric Pressure Sensor Replacement
A Barometric or ManifoldAtmospheric Pressure (MAP) Sensor is a device used to monitor barometric or atmospheric pressure relative to your vehicle. The intake manifold's atmospheric or barometric pressure as well as the air inside it is sensed by this sensor, which sends a signal to your Engine Control Unit (ECU). The ECU then uses this info along with data on the temperature of the air to calculate air density and how much fuel should be added to the mixture for efficient operation.
What You'll Need
- New sensor
- Soldering iron
- Wire stripper
- Wire cutters
Step 1: Mount the new sensor somewhere inside the engine bay area. Remove the old sensor and put the new one in the same place. It's easier to install this MAP sensor if it's mounted on the engine bay's passenger side. When removing your old sensor, know which wire is the signal wire for it. Also keep in mind that the ECU is typically found under the passenger's side carpet.
Step 2:Bypass the old sensor if you're installing an aftermarket sensor. You'll need to splice the power wire from the new sensor to the stock sensor's power wire. This should also be done with the ground wire.
Step 3:A vacuum source should be established for the sensor to measure pressure correctly. You should connect the vacuum line that runs from the sensor the source by running all the sensor wires through the firewall into the passenger side's door. From there, wire the sensor into the old sensor's power source.
Step 4:The breakout board comes with five connections called pins or holes that you can solder header pins or wires into. When it comes to connecting the wires to the board, you could use a male/female jumper wires and solder a five-pin length of male-male header strip to connect the wires unto the board.
Step 5: Your car manual should provide you the information on which plug goes to where. For example, a barometric pressure sensor can include an interface with two digital wires, a flexible voltage range of 1.8 to 3.6 volts, and factory-calibrated wide barometric pressure range. Some of them are even 5-volt compliant with an i2c level shifter circuit and a 3.3-volt regulator.
Step 6:Connect your breakout board'sSDA pin to the I2C Data (Analog 4), SCLpin to theI2C Clock (Analog 5), the GND pin to ground, and the VIN pin to the 5-volt voltage pin. Don't forget to make sure you're using the right microcontroller for your barometric pressure sensor.
Step 7:Calibrate the sensor.Use a UTEC menu for it. They're found under Edit Maps, Parameters, and Special Constraints. The two MAP calibrations cover one for the gradient and one for the intercept. Aftermarket sensors come with a minimum to maximum voltage and pressure figures to help you determine the gradient and intercept. The line equation can be calculated using Excel or a calculator.
Step 8:Once the sensor is mounted and calibrated, test drive the car around to make sure that your new equipment is running as smoothly as possible. Any problems coming from the MAP or barometer pressure sensor is likely due to loose or poorly soldered wiring.
The barometer pressure sensor typically offers a 300-1100 hPa pressure measuring range with accuracy of 0.02 hPa during the advanced resolution mode. You should specifically search for rugged, high-precision chips with long-term stability and is factory-calibrated.