Intermittent Fault 19558 2005 Passat

[jonlowe]

2005 Passat TDI
I'm getting the above fault intermittently. I removed the V157 intake manifold flap assembly and cleaned a bunch of soot off of it this weekend, but I'm still getting the fault. I cleared the fault, it stayed away for a few days, then set a DTC again. Is there a way with VCDS to cycle the flap assembly with the ignition on, but the car not running, so I can see if it is sticking or there is a dead spot in the motor that drives it? I know there is a way to cycle the EGR valve, but I haven't seen anything on the flap.
Thanks,
Jon

 

[jonlowe]

To answer my own question, yes there is. Go to the Engine control module, select Output Tests under Advanced Functions, and cycle thru the various tests until you come to the V157 test. If your engine is running, when this test cycles V157, the engine will die because it closes it completely.

I took the top off of my flap assembly as shown here:
http://pics.tdiclub.com/data/500/B5_IFM.pdf

It takes a fair amount of persuasion to get the top off since the contacts from the top press into receptacles on the bottom. I noted that the contacts in the top appeared to be brass or copper, and the ones in the bottom appear to be plated with something, so there may be a dissimilar metal thing going on here causing my intermittent MIL. I cleaned the contacts, and pressed the contacts together as noted in the PDF above. The gears were fine, and the mechanism rotated freely in both directions. Put it all back together, cleared the DTC, and now I have to drive it for awhile to see if that fixed the problem. I cycled it several times as noted above with my VCDS, and it always worked ok.

This thing is really pretty simple. The circuit board in the top just supplies current to the motor in the bottom half. There is no direct feedback mechanism from the gears or output shaft, so the electronics inside don't know what the position of the flap is. The circuitry may pulse the motor to provide intermediate flap positions, except at shutdown when the motor drives the flap totally closed for a brief time. Longer pulses close the flap more. A spring drives the flap to the fully open position when there is no current to the motor. There is no way this thing is worth what VW wants for it ($576 currently!), given its unsophisticated design.

The electronics are potted, so there is no way to see if anything is going on there. Since mine is an intermittent fault, I doubt it is the circuit board.

I didn't try to disassemble the bottom half with the motor, as the flap assembly is still in the car. If it fails completely, and I have to buy a new one, I will try to see if the motor has an issue.

If someone has one that was replaced, I'd be interested in dissecting it to see what the failure mode was.

Jon

 

[Lug_Nut]

Is there a text description of the fault, or could you describe the operational symptoms?

 

[jonlowe]

The VCDS says "Motor for Intake Manifold Flap (V157) - No Signal"

In my case, there wasn't a driveability problem, just an annoying CEL/MIL being set, and then going away, only to come back in a few days or a few weeks. I wanted to kill the issue, so that this CEL didn't mask a more serious problem if one came up.

It would come on just after starting the engine, and VCDS said that it was happening at zero RPM, so, for some reason, it was throwing the code during startup. Never had it occur anytime after startup.

EDIT: If it sticks shut, the engine won't run, as it cuts off all air to the intake manifold. If it doesn't operate, the engine will shudder during shutdown. It also works in conjunction with the EGR to regulate the amount of fresh air vs. recirculated exhaust that the engine gets.

Jon

 

[Lug_Nut]

OK, I just don't recognize the SAE code to cross reference it to the VW code.
My B5.5 had a different issue and I wasn't sure if your SAE code was related to the problem I had.

Is the intake flap a variable position device? It may just be an intermittant loss of electrical signal at some specific point in its stroke. Because it occurs at start-up I'd suspect zero (or 100) percent.

 

[jonlowe]

19558 equates to P3102. As I stated in my analysis of the device, it could have intermediate positions, but only if it is pulsed, as there appears to be no direct feedback mechanism from the flapper to the controller. It is spring loaded to the fully open position, and timed pulses could keep it open a predetermined amount.

So far, after cleaning the internal contacts, it hasn't thrown the code again, but I will know more in a few weeks.

Jon

 

[Keithuk]

Hi Jon.

You now have my Free EOBD II Error Codes software


VAG Error Code: 19558

EOBD II Error Code: P3102​

Fault Location:
Motor for Intake Manifold Flap (V157) - No Signal​

Possible Cause
Hard Shudder when turning OFF the Engine.​

Fuse(s) faulty.
Wiring and/or Connector(s) from/to Intake Manifold Flap Motor (V157) faulty.
Intake Manifold Flap Motor (V157) faulty.​

Possible Solutions:
Check Fuse(s).
Check Wiring and/or Connector(s) from/to Intake Manifold Flap Motor (V157).
Check/Replace Intake Manifold Flap Motor (V157).
Perform Output Test. ​

 

[Eliminateur]

To answer my own question, yes there is. Go to the Engine control module, select Output Tests under Advanced Functions, and cycle thru the various tests until you come to the V157 test. If your engine is running, when this test cycles V157, the engine will die because it closes it completely.

I took the top off of my flap assembly as shown here:
http://pics.tdiclub.com/data/500/B5_IFM.pdf

It takes a fair amount of persuasion to get the top off since the contacts from the top press into receptacles on the bottom. I noted that the contacts in the top appeared to be brass or copper, and the ones in the bottom appear to be plated with something, so there may be a dissimilar metal thing going on here causing my intermittent MIL. I cleaned the contacts, and pressed the contacts together as noted in the PDF above. The gears were fine, and the mechanism rotated freely in both directions. Put it all back together, cleared the DTC, and now I have to drive it for awhile to see if that fixed the problem. I cycled it several times as noted above with my VCDS, and it always worked ok.

This thing is really pretty simple. The circuit board in the top just supplies current to the motor in the bottom half. There is no direct feedback mechanism from the gears or output shaft, so the electronics inside don't know what the position of the flap is. The circuitry may pulse the motor to provide intermediate flap positions, except at shutdown when the motor drives the flap totally closed for a brief time. Longer pulses close the flap more. A spring drives the flap to the fully open position when there is no current to the motor. There is no way this thing is worth what VW wants for it ($576 currently!), given its unsophisticated design.

The electronics are potted, so there is no way to see if anything is going on there. Since mine is an intermittent fault, I doubt it is the circuit board.

I didn't try to disassemble the bottom half with the motor, as the flap assembly is still in the car. If it fails completely, and I have to buy a new one, I will try to see if the motor has an issue.

If someone has one that was replaced, I'd be interested in dissecting it to see what the failure mode was.

Jon

Jon, interesting, i have a failed ASV but hte failure mode in my model car is that it blows the fuse(which also feeds the cooling fans) so you get a v157 and then overheated engine... fun...
I opened mine (038 128 063G) and the electronics are not potted and vastly different, mine has a position sensor with a sliding potentiometer(terrible design decision), motor moved freely(it was flooded with oil) so i cleaned it throughly, checked the drivetrain with a bench psu and it moved somewhat(small psu) and it doesn't has contacts like yours either.
So we put it back together. flooded it with new oil, worked for a day then blew the fuse again.. it's been like that for a year