Jump to content

Guide: Cleaning MAF sensor


Recommended Posts

This works for both 2.4 and 3.0. This guide is based on the 3 litire model, but you can do the same process with the 2.4. You just need to locate your MAF sensor beforehand. This will be situated after the air Filter box and the engine.

MAF Sensor on the Toyota Alphard - 3.0 V6

What is a MAF sensor?
Your mass air flow sensor or “MAF” detects the volume of air as it enters your engine by heating up a thin wire or resistor. The computer in your car then measures electrical resistance through the MAF as the air flowing through the sensor cools its components down. With a firm understanding of how much air is flowing into your engine, the computer can then direct fuel injectors to add more or less gasoline to the air/fuel mixture.

First off you are going to need a can of Isopropyl Alcohol (excuse the state of my old can :D ) Also be weary of buying MAF sensor cleaner. It's the same stuff and it's twice the cost. Go to your local maplin or ebay and purchase a can for around £4

20170817_171513.thumb.jpg.447e32af2764821a1a343c254c4e37f1.jpg

 

You also need a stubby screwdriver. I lost mine so using a short screwdriver.

20170817_171956.thumb.jpg.70e9f5a1ba59b79083502ccd4de9b5e0.jpg

Unscrew the top housing of the sensor and gently remove.

20170817_172106.thumb.jpg.01ba8e97aca51280459159e6fa4d30d6.jpg

This will expose the red diode (does not look red at the moment as it's dirty) Spray this diode with Isopropyl liberally.

 

20170817_172703.thumb.jpg.4b89b70695224e9c7921ed01dd0543ea.jpg

Now for the dodgy bit. Some people recommend not to touch the sensor, however, i have always given mine a very light rub with a cotton wool bud. So be careful here.

 

20170817_172830.thumb.jpg.ce05c342a34791b254e5b4c6fe84b712.jpg

The dirt is now off the diode.

 

20170817_173051.thumb.jpg.9bb6a27ba45315aff9fbde3e27ae9e41.jpg

Now look inside the may sensor assembly and you will see two small blades. Give then a good squirt. 

Shake off residual alcohol and wait for the sensor to dry. Takes about 5 mins.

Refit to car.

If you had a Check engine light due to the MAF sensor then this is a good time to disconnect the negative terminal on the battery for 15 mins to reset the ECU and clear any codes. I have seen the car also go in to limp home mode by simply having a dirty sensor.

The dealer hates people knowing how to clean these as most of the time all they need is a simply clean while the dealer wants to help himself to £200 from you for simply replacing a dirty sensor. All Done for just £4 and 15 mins you could say a whole bunch of notes.

 

  • Like 2
Link to comment
Share on other sites

  • 9 months later...

MAF problems seem common on these motors... More common when people have fitted certain brands of paper air filter which seem to leave a bit of a film of dust on the MAF. I've fixed many problems on these engines caused by dusty MAF's. 

Don't confuse the air flow meter part of the MAF unit with the intake air temp part of the MAF unit, there are two sensors (IAT and MAF sensor) inside the MAF housing, a dusty IAT sensor is very unlikely to give problems but the MAF (further inside the unit) does give problems if dusty. 

 

Simon

Link to comment
Share on other sites

  • 3 years later...
  • 2 months later...
  • Alphard Club changed the title to Guide: Cleaning MAF sensor

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.