Air Intake Inlet Manifold Flap Adjuster control unit diagnostic and repair guide
This is actually an electronic control unit for the intake manifold flap for several VW and Audi cars. I assume they are on other vehicle too but in some other shape. I would try to demonstrate as simple as I can how this unit is build up and how to diagnose.
Days ago, I got this part in my mailbox for diagnosing and repairing from a nearby car repairer garage. Actually the car comes up with several error codes and one of them was the ” P2015 – intake manifold damper sensor, implausible signal “. The first think what went over my head was, I deal with an electronic control unit who has an implausible signal on his sensor part.
Ok, most of the technicians would suggest you to buy a new intake manifold and change your intake manifold in your car. This is actually a big mistake and a very expensive game and you didn’t solve your problem with it. Let’s talk about how this unit is build up and from where directly this implausible signal is screaming from.
This is an example of an air intake manifold with an electronic control unit.
The electronic control unit is build up from several gears, a DC 12V brushless motor, a flap position sensor part and a magnet. It is very similar as the electronic throttle body as I wrote in one of my article before. Here is how this unit looks under the hood.
The most major problems why this unit is in a bad condition:
– Dirt in the air intake manifold and the flaps can’t move freely.
– Blocked flaps in the air intake manifold.
– Brocken parts like a broken spring or failed / broken gear.
– Bad control unit.
– Bad electro motor.
– Some calibration problem as it was the case in this unit, etc.
The spring is use to move back the flaps to its initial point. If ECU requests a specific position then the motor has to overcome the power of the spring and moves the flaps in a desired position what is initialized by the ECU.
The magnet is actually in a relation with a hall sensor which is integrated into the black housing. It is used to tell the ECU where the flaps are until operation condition.
The motor is used to move the flaps to a desired position or angle what is requested by the ECU
The motor is actually a 12v DC brushless component.
The diagram part:
On the J623 you can see the T60/50 or T60/27 or T60/10 this means the 60pin connector where the wiring is exactly on the 50 or 27 or 10 pin on the ECU side.
So, if you disconnect the T60 connector from the ECU and the T5q connector from the intake manifold control unit, than you can check for continuity the wiring between the ECU and the intake manifold control unit.
Testing the signals from the ECU:
Check if reference voltage +5V are coming from the ECU with a voltmeter between pin 1 and 3 on the T5q connector.
Check with scope between pin 4 and 5 is there a signal of 12V or a PWM signal from the ECU for a short time ( around 5sec ) until somebody turn on the car but not crank.
Testing the hall sensor part:
Connect to pin 1 +5V and to pin 3 GND.
Connect a voltmeter positive lead to pin 2 and the negative lead to pin 3.
When the adjustment arm is in a zero position, you should read a voltage
around 0.4v. If this condition is under that voltage you will get an error code of
” P2015 – intake manifold damper sensor, implausible signal ”
If you move by finger the adjustment arm to the max end position, than you should read a voltage around 4.5-5V. If this condition is over that voltage then you will got also the same error code as mentioned before.
If you measure continues the voltage until the adjustment arm is moving, you should get a rising or falling voltage between 0.4 – 5V it depend in which way is the adjustment arm moved. If you don’t have this kind of reading then you have a hall sensor problem.
Testing the motor:
This motor is a DC 12V brushless motor, and the terminals are directly connected to the ECU and have nothing to do with the hall sensor electronic, I decided to directly power from my lab power source.
My setup on the lab power source was U=12v @ Imax=1.5A.
The adjustment arm should start moving, if no movement or some squeeze noise, over current shown on the power supply, no current consumption than you have a motor failure.
Of course there could be some broken parts also the reason for a non working air inlet control unit.
The problem and how I solved this unit:
The problem in this unit was a miss calibration of the mechanical parts.
Let’s check in the picture what was happened:
The green arrows show the rotation direction of the mechanism.
On this picture the zero point is reached, but the stopping wings are out of calibration. Now the reading on the DMM is 0.25v because the corrupted distance. Check the next zoomed picture left. Also the problem on the other wing too. I think this weak point is made by the manufacturer because of the commercial nature.
The major problem is the 0.25v. This is an out of range signal and the ECU won’t initialize the whole unit. The ECU will set an error. If we go around somehow solving this corrupted distance and bringing the unit back to a reasonable position, where the initial voltage is not under 0.4v then we are in the race again.
Here is how I solved this and I got some “extra features too”
– Drilled a hole with a 2.5mm drill.
– Made a screw thread for the M3 bolt.
Now I physically corrected the moving path of the adjustment arm. With this bolt I can fine tune the correct position of the adjustment arm until it reach the 0.4v.
After this repair, I also made a software calibration of the air inlet control unit through my diagnostic tool and deleted the P2015 error from the car ECU.
The unit was put on the car and the car is on a test drive around 3 – 4 days without any problems and no error message comes on the vehicle dashboard any more.
Ok, this warning should maybe be on the beginning but I assume people read stuff before they do stuff. This is my way how I do stuff. So, what I found inside the unit when I lift the black cover was lot of dust. That dust is actually from the plastic parts inside the unit.
Let’s check what type of dust is it:
On this gear is written “PPA-GF30+15%PTFE”
PPA – Polyphthalamide, some sort of nylon
GF30 – Glass filled 30%
PTFE – Polytetrafluoroethylene is actually Teflon ( added 15% )
I assume this combination of dust is dangerous for human lungs. But! This information gives as another valuable info. Let’s say, we wish to glue together some material with this gear, then we have to use a glue who can glue PPA+G+PTFE and the other material let’s say iron Fe.
I hope you enjoy this tutorial and will save lot of repair time.
This article was prepared for you by Christian Robert Adzic from Novi Knezevac-Serbia.
Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.
P.S- If you enjoyed reading this, click here to subscribe to my blog (free subscription). That way, you’ll never miss a post. You can also forward this website link to your friends and colleagues-thanks!
Note: You can check his previous post in the below link: