About the Hitachi MAF sensor. --->
#1
AudiWorld Super User
Thread Starter
Join Date: Nov 2000
Posts: 4,219
Likes: 0
Received 0 Likes
on
0 Posts
About the Hitachi MAF sensor. --->
First you need a "tamper resistant" torx driver #20. That's the one with the whole in the bottom.
Taking the sensor assembly out reveals that it is, not surprisingly, a hot wire anemometer. The wire is replaced by more modern <b>thermistors</b> that are much more rugged than mere resistance wire. But it's the same principle.
<img src="http://pictureposter.audiworld.com/12010/hitachimaf.jpg">
This is looking at the sensor in the direction of the air flow.
<img src="http://pictureposter.audiworld.com/12010/hitachimaf2.jpg">
A closer look at the working parts shows one thermistor (green arrow) exposed to the free flow of air. It is probably the Air Intake Temperature Sensor. In the cavity two more thermistors can be seen. After passing those thermistors, the air is channeled to the right through a duct that is open to the intake flow but at right angles to it. This duct probably controls reverse flow at low RPMs.
<img src="http://pictureposter.audiworld.com/12010/hitachimaf3.jpg">
Finally, a look at the back of the sensor looking upstream against the flow.
This sensor appears to operate by a type of Wheatstone bridge circuit that's contained in the small cover space.
Happy Motoring.
Taking the sensor assembly out reveals that it is, not surprisingly, a hot wire anemometer. The wire is replaced by more modern <b>thermistors</b> that are much more rugged than mere resistance wire. But it's the same principle.
<img src="http://pictureposter.audiworld.com/12010/hitachimaf.jpg">
This is looking at the sensor in the direction of the air flow.
<img src="http://pictureposter.audiworld.com/12010/hitachimaf2.jpg">
A closer look at the working parts shows one thermistor (green arrow) exposed to the free flow of air. It is probably the Air Intake Temperature Sensor. In the cavity two more thermistors can be seen. After passing those thermistors, the air is channeled to the right through a duct that is open to the intake flow but at right angles to it. This duct probably controls reverse flow at low RPMs.
<img src="http://pictureposter.audiworld.com/12010/hitachimaf3.jpg">
Finally, a look at the back of the sensor looking upstream against the flow.
This sensor appears to operate by a type of Wheatstone bridge circuit that's contained in the small cover space.
Happy Motoring.
Thread
Thread Starter
Forum
Replies
Last Post
apoelistas
Q5/SQ5 MKI (8R) Discussion
78
05-29-2020 11:41 PM
S4AVT
A4 (B6 Platform) Discussion
3
05-08-2004 05:30 PM