fault p1031

From looking at my logs the resolution is more like 1.6%.
Yes, your right, or 1.2 (98.8 - 100) but that would be unlikely, if the actual resistance element was only 1/10th of a turn, I think.
If there is a mechanism in there, it might well be possible to take it apart, and repair it. The worn or dry mechanism, (if there is one) could be another source of sticktion.
Mac.
 
Yes, your right, or 1.2 (98.8 - 100) but that would be unlikely, if the actual resistance element was only 1/10th of a turn, I think.
If there is a mechanism in there, it might well be possible to take it apart, and repair it. The worn or dry mechanism, (if there is one) could be another source of sticktion.
Mac.
The wiring diagram shows a transistor in the unit so there is more in there than just the potentiometer. Would be interesting to see what is inside.
 
It probably has another resistor and is functioning as a potential divider. The ECU will measure voltage rather than resistance.
 
http://www.volkspage.net/technik/ssp/ssp/SSP_253.pdf

Not sure if you have read this already. This is the Bosch Design and Function doc on the system
Thanks. This helps to get the terminology correct. As far as I understand it, if either the solenoid value (N316) or the potentiometer (G336) fail, the engine will operate in homogeneous charge mode. This means that the intake manifold flap will not be actuated and the air will flow through both ducts. So basically, if it moves the sensors should be good and it is either a mechanical or calibration (adaption) issue. If the 15mm value that Andy measured is correct, every 1mm of travel equals 6.67%.
 
While on the school run this evening I had a few minutes so hooked up the VCDS to see if I could figure out why it was reading 1.6% but now 33.7%. To my surprise it was reading 1.6%, so I immediately switched on logging. In my excitement I forgot to record the engine RPM but we know from the previous run that the swirl flap opens at around 3200 rpm. As everything seemed fine, I cleared the eror code then tried to go to Basic Settings. It showed ADP. Run and stayed like that. After a minute I switched the ignition off, left the car while I picked up the the kids. So far the engine light hasn't come back on and I have made at least one stop and restarted the car about five times.
The good news is that I have done two more school runs/commutes and the check engine light hasn't come back on for more than 24 hours. That is the longest time I haven't seen it on since I bought the car! If it helps, I could try to summarize this thread in a single post for others who have this issue. Just let me know where it should be located.
 
Thanks. This helps to get the terminology correct. As far as I understand it, if either the solenoid value (N316) or the potentiometer (G336) fail, the engine will operate in homogeneous charge mode. This means that the intake manifold flap will not be actuated and the air will flow through both ducts. So basically, if it moves the sensors should be good and it is either a mechanical or calibration (adaption) issue. If the 15mm value that Andy measured is correct, every 1mm of travel equals 6.67%.

That sounds about right but there are a number of sensors that must also be working correctly in order for the system to function correctly:

- the engine is in the corresponding engine load and speed ranges

- there are no exhaust emission faults in the system

- the coolant temperature is above 50°C

- the NOx sensor is ready, and

- the temperature of the NOx storage catalyst is between 250°C and 500°C

If the above conditions are met, the engine management system can change over to stratified charge mode.
 
So for example as I have an Exhaust temp sensor issue:

17861 - Exhaust Gas Temp Sensor 1 (G235) - P1453 - 35-00 - Open or Short to Plus

I'm guessing that this may be related and I will address this problem first before going back to the "7439 - Intake Manifold Tuning Valve (N316) - P1031 - 35-00 - Setpoint Not Reached" problem
 
So for example as I have an Exhaust temp sensor issue:

17861 - Exhaust Gas Temp Sensor 1 (G235) - P1453 - 35-00 - Open or Short to Plus

I'm guessing that this may be related and I will address this problem first before going back to the "7439 - Intake Manifold Tuning Valve (N316) - P1031 - 35-00 - Setpoint Not Reached" problem
Yes and no. If the setpoint is 0% it can be investigated without the engine running. If the set point is 100% then it tried to go into FSI mode.
 
Yes and no. If the setpoint is 0% it can be investigated without the engine running. If the set point is 100% then it tried to go into FSI mode.

Interesting you say that as my latest data upload (in my project thread) I believe shows 100% and 0% (requested) and there was no movement on the rod (same position of 24.3% recorded and also this was before the car was beyond 50Deg at which the car will not be permitted to enter FSi mode according to Bosch?, so I'm guessing if you are correct that after I fix the heat sensor I may still have a vacuum issue.
 
Interesting you say that as my latest data upload (in my project thread) I believe shows 100% and 0% (requested) and there was no movement on the rod (same position of 24.3% recorded and also this was before the car was beyond 50Deg at which the car will not be permitted to enter FSi mode according to Bosch?, so I'm guessing if you are correct that after I fix the heat sensor I may still have a vacuum issue.
I just had a quick look at the data. Engine off it expects 0%, Idle 100% (FSI mode) and 3200 RPM 0%. Your flaps seem stuck to the ECU. Disconnect the vacuum pipe at the solenoid valve, swivel it under the air intake and give it a good suck.
 
One thing that's come out of the last few days of this thread, for me at least, is that error codes/dash warnings, that are typically assumed to be a mechanical flap problem, may not always be so.
The flaps are moving constantly, other than on a long M/Way run, so getting gummed up may not be as likely as thought.
Mac.
 
I just had a quick look at the data. Engine off it expects 0%, Idle 100% (FSI mode) and 3200 RPM 0%. Your flaps seem stuck to the ECU. Disconnect the vacuum pipe at the solenoid valve, swivel it under the air intake and give it a good suck.

The flaps defo move just not with the actuator. I'll check for vacuum before I give it a good suck! :cool: there is a VAG special tool to test the system (VAS 6213), but I have found this which will do the same thing.

https://www.ebay.co.uk/itm/Eisco-PH01697-Hand-Vacuum-Pump/123608874649
 
One thing that's come out of the last few days of this thread, for me at least, is that error codes/dash warnings, that are typically assumed to be a mechanical flap problem, may not always be so.
The flaps are moving constantly, other than on a long M/Way run, so getting gummed up may not be as likely as thought.
Mac.

Just as likely to be another sensor failure or a vacuum problem unless the rod is actually broken which infers sticking.
 
Final bits of information. The potentiometer (G336) had 2.6v when the flap is open and 3.9v when the flap is closed. Here is a picture showing the travel of the vacuum actuator arm. With the engine off, I lined up the top of the bracket with the top of the bolt and made a Tipex mark. After starting the engine I did the same. You can see in the picture below the travel. This can probably be done more accurately and measured if the fuel pipes are moved out of the way.
p1031.jpg
 
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Good pic, and an easy basic step in troubleshooting. If you observe full travel (Andrew's 15mm), when the engine runs, and VCDS confirms it (100% no engine run, 0% engine idling) , your flaps, and their control system are fine.
Mac.
 
I am wondering if the voltage seen in group 142 is the set point. It looks suspiciously close to what I measured.
 
Final bits of information. The potentiometer (G336) had 2.6v when the flap is open and 3.9v when the flap is closed. Here is a picture showing the travel of the vacuum actuator arm. With the engine off, I lined up the top of the bracket with the top of the bolt and made a Tipex mark. After starting the engine I did the same. You can see in the picture below the travel. This can probably be done more accurately and measured if the fuel pipes are moved out of the way.
View attachment 59652

I posted a wee update on my project thread. I have now tested again moving the actuator rod and I can see the % move from 24% to 100%, however oddly enough the voltage does *not* move at all. The plot thickens!
 
I posted a wee update on my project thread. I have now tested again moving the actuator rod and I can see the % move from 24% to 100%, however oddly enough the voltage does *not* move at all. The plot thickens!
Voltage in VCDS? It is seems static. Try back probing the middle (yellow) wire on the potentiometer.
 
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