How To Clean Maf Sensor On 2007 Trailblazer

Fifty-fifty a well-maintained engine volition collect deposits of dust, dirt, crud, carbon and oil — both inside and outside. These deposits can cause many problems, such as interrupted air period, fouled spark plugs or fuel injectors, engine overheating or skewed sensor readings. MAP sensor cleaning may exist necessary if yous're experiencing poor fuel economic system, crude idle, hesitation or stalling on acceleration, or an illuminated check engine light.

In fuel-injected engines, the engine control module (ECM) calculates fuel injector pulse based on several other sensor readings, such every bit engine RPM, engine coolant temperature (ECT), intake air temperature (IAT) and air–fuel ratio (AFR), among others. Air mass is a disquisitional measurement the ECM uses to calculate fuel injection, and nigh engines are either equipped with a manifold absolute pressure (MAP) or mass air flow (MAF) sensor. Some turbocharged engines utilise both MAF and MAP sensors.

You tin can usually tell if you lot have a MAP sensor if y'all cannot find a MAF sensor in the intake air tube before the throttle body. The MAP sensor is usually mounted directly to the intake manifold, somewhere afterwards the throttle body, though some are mounted on the firewall or elsewhere in the engine bay, connected to the intake manifold via a vacuum line. In some vehicles — older K-cars, for instance — the MAP sensor is mounted past the ECM, connected to the intake manifold via a long vacuum hose. The MAP sensor continuously measures the pressure/vacuum in the intake manifold.

Checking a MAP Sensor

You lot tin can easily exam a MAP sensor with a vacuum pump and multimeter. First, remove the vacuum line or remove the MAP sensor from the intake manifold. With the MAP sensor connected and the ignition in the "on" or run position, check the voltage output on the MAP sensor signal wire. Turbocharged engine MAP sensors volition also respond to pressure, and their pressure/voltage readings may exist unlike. Either way, check your repair transmission for the wiring diagram and specific voltage readings.

The typical MAP sensor should read around 4.7 5 when open to the air. Using the vacuum pump, you should see voltage drib to around 1 V at 20 inHg vacuum. Repeat the test and note that as yous draw and release vacuum/force per unit area, the voltage should respond instantly.

MAP sensors contain no moving parts, and they don't typically wear out, but cleaning the MAP sensor may be required if it'due south contaminated by carbon or other deposits from the engine. If voltage is wearisome to reply to pressure changes, contamination could be responsible.

MAP Sensor Cleaning Pace-past-Step

MAP sensor cleaning simply entails a few more steps:

Disconnect the MAP sensor connector and put on safety gloves to protect your peel. Safety glasses are a good idea, as well.
Employ an electrical parts cleaner on a soft rag or paper towel to clean the outside of the MAP sensor.
Spray the electrical parts cleaner into the sensor port — a couple of spritzes are usually sufficient. Milk shake out the excess and permit the MAP sensor dry.
Check the MAP sensor vacuum hose or intake manifold port for additional contamination. Make clean these with electrical parts cleaner and a castor if necessary.
Once everything is dry out, which shouldn't have very long, the MAP sensor should be clear of contamination. Reinstall the MAP sensor.

MAP sensor cleaning is an easy style to restore engine performance and fuel economy. To keep other air and fuel system parts clean, consider an intake organization cleaner the next time you maintain your engine.

Check out all the chemic productsbachelor on NAPA Online or trust ane of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more than information on MAP sensor cleaning, chat with a knowledgeable expert at your local NAPA AUTO PARTS shop.

Photograph courtesy of Wikimedia Commons.

Benjamin Jerew View All

Ben has been taking things apart since he was 5, and putting them back together once more since he was 8. After dabbling in DIY repairs at home and on the farm, he found his calling in the CGCC Automobile Repair program. After he held his ASE CMAT for 10 years, Ben decided he needed a alter. Now, he writes on automotive topics across the spider web and around the world, including new automotive technology, transportation legislation, emissions, fuel economy and auto repair.