Rear wiper inop but ok with vcds test

[Pypo]

I all i hope you re fine during these strange days....

I have a pb with my rear windshield wiper on A4 avant 2009

So , when actioning at the control wheel , it doesn't t work , with vcds test it s ok and also when i drive rearward .

Anyone could provide me help ? drawing or what to check ?

Thanks for your support

Cheers

Francky

[Theiceman]

i dont have an avant but it sounds like the car is locking out the wiper through software for some reason . it sees a condition it doesnt like. Id run a scan with vcds and see what it is telling you . I think some other condition is setting. like a door sensor or hatch open warning or something like that

[Pypo]

thanks will try that

[Smac770]

Sounds more like a problem with the wiper stalk than the wiper.
When you move the wiper stalk back from rear wiper off to rear wiper enabled, do you get the one sweep of the wiper?
When you push the wiper stalk back to activate the rear wiper washer, do you get nothing, washer spray, wiper movement, or washer spray and wiper movement (that last one being the correct execution).
That the output test is ok (I've never done, it moves the wiper? And the wiper moved?) and that the wiper moves when in reverse while the front wipers are active would imply the wiper motor is just fine.
You should check the measuring blocks of address 0x16 and see if the J527 is acknowledging all the movements of the wiper stalk.

[RPMtech147]

Sound like the multifunction switch. Are there actual values (groups) for switch position/button activation in VCDS?

[Theiceman]

why would the switch fail when driving forward but not backwards ?

[Smac770]

The reverse engagement is not dependent on the wiper being enabled at the stalk. If the front wipers are active, be it on or rain sensing, the rear wiper will wipe when in reverse.

Yeah, all the stalks and wheel buttons and toggles can be monitored in the measuring blocks of the J527, steering, address 0x16. Looks like the turn signal and high beam operations are in block 01, wiper stuff is in block 01 and 02.

So I see Not Oper for rear wiper, but if I push the right stalk back one notch to enable the rear wiper, the value changes to Activated, and the rear wiper wipes every few seconds (my fronts are in the intermittent position).

[Theiceman]

Wow.....only the Germans....


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[Pypo]

HI guys sorry for the late reply so i have this on vcds :

Steering wheel multifunction wrongly coded
code 01044 in groupe 16

When i went thru it says , rear shield wiper not installed , washer not installed

Looks like when the garage replaced the steering rack they made a mistake for coding ?

If anyone could help how to fix this, i m a rookie with vcds

Thanks

Francky

[Smac770]

What value is coded at address 16 currently?

[Pypo]

[Pypo]

- - - Updated - - -

As said i m not at ease with vcds ,

[Smac770]

Mine is 00 00 17. What is bit 0 of the third byte for?

[Pypo]

Ok problem fix, just change to 17 , rear wiper was not selected was set as 16

Cheers Mate

[WtA4WtQ5]

Nice! I was not so lucky with my 2011 Q5, it was the multifunction switch and VCDS pointed to it as the issue.

[Fast4esT]

I am in this same boat, my rear wiper on my 2014 Q5 has stopped working all together however the sprayer still works. I would like to connect with VCDS before I resort to pulling the trim and panels off to check out the pump/wiring itself.
I do not know what to do after I connect with VCDS, which block to look at, how to decipher if my multifunction switch has failed.
any pointers?

thanks

[Smac770]

Go to control module 16 - steering electrics. Then measuring blocks. You should see labels for the blocks, and you'll just have to sort which one(s) have the values for the status of the wiper stalk. Once you find them, you should see the values change as you move the stalk around.

[Fast4esT]

sweet, thanks!

[Fast4esT]

connected VCDS, the rear wiper shows up as inactive
when I push the switch forward it says active
when I push the sprayer on:
sprayer says active
wiper says inactive

Im assuming this is correct operation

following this TSB
https://testing-public.carmd.com/Tsb...107425/A921511

with wiper switch pushed forward to activate rear wiper I read the following values

I get 11.32 volts between pins 1 and 4
I get 6.5 volts between pins 4 and 3
I get 11.32 volts between pins 4 and 2

voltage difference was more than 0.5 volts between pins 4/3 and 4/2

according to TSB I may have a broken wire?

then I noticed that the wiper had wiped he glass, it started working momentarily. then stopped again

I then jumped pins 1 and 2 and the motor works.

so I narrowed out the motor being bad and believe the switch also to be ok.

for fact that the wiper worked for a moment I thought the break in the wire must be in the rear hatch opening. I pulled the trim and undid the harness black sticky cloth and saw no broken wires, I went as far as I could see into the roof following the harness, nothing broken. I did not proceed into the wiring going down the side of the hatch, cannot imagine wire breaking down there, it all stays pretty still.

I did not check the harness as the TSB states to do in the driver door opening, guess that will be my next inspection.

I just don't get why it started working for a minute

[Smac770]

The V12 rear wiper motor has four pins:
1 - ground
2 - from J519
3 - from J519
4 - fused 12v (in an A4, right rear fuse block, column D, fuse 8; Q5 might be the same)

So 4 to 1 should measure battery voltage.
It's unclear exactly what the signaling is on the two lines (pins 2 and 3) from the J519 are.

J519 T17l (black 17-pin) pin 3 > gray/red > to V12 wiper motor pin 2 and to V5 washer pump pin 1
T519 T17l (black 17-pin) pin 4 > gray/black > to V12 wiper motor pin 3 and to V5 washer pump pin 2

(on a sedan, it's just J519 to V5, no V12 wired in; the V400 front wiper motor is managed completely separately)

That your 4 to 1 is only 11.32 volts, that's low. Real low if that's actual battery voltage. Any voltage below 12.0 is possible to cause odd behavior.
If you measure battery positive post to battery negative post, what do you measure?
If that measurement is fine, if you measure from the fuse noted above to the battery negative, what do you measure?

As for testing the wires from the J519 to the V12, probably easiest to pull the black 17-pin off the J519 (under the dash, behind the relays behind the headlamp switch) and do a diode test (voltage drop test) to measure the drop from the pin 3 to the V12 plug pin 2, and from the pin 4 to the V12 plug pin 3. If your meter doesn't have diode mode, then just a resistance measurement. Yes, it's going to need some long meter leads. But better than cutting open the harness if there's no measurable voltage drop from J519 to V12.

[Fast4esT]

Thanks for that, I’ll check my battery voltage and go from there

[a4audi4fun]

On my B7, I had an intermittent rear wiper problem because water from the sprayer had leaked into the rear wiper motor. For that model year, the water path went through the spindle of the wiper motor - would think there's a high probability the same design is used on the B8.

BTW I don't know what wiper blade is used for the B9 Avant but I switched over to the Q5 rear Aeroblade wiper arm and it does a much better job of wiping than the original B7 blades.

[Smac770]

Bosch is the normal supplier for the rear wipers.

C6 A6, Bosch H383, 375mm (15") plastic tree
A4 B7, Bosch H772, 350mm (14") plastic tree
Q7 4L, Bosch H772

A4 B8, Bosch A402H, 400mm (16") beam
Q5 B8, Bosch A332H, 325mm (13") beam
Q7 4M, Bosch A360H, 350mm (14") beam
A4 B9, Bosch A402H?
Q5 B9, Bosch A360H
Q8 4M, Bosch A402H
C8 A6, Bosch A402H

So starting with the B8 release, Audi moved from the old plastic tree design to the beam design. Different lengths depending on vehicle application. The A blades might be better than the H blades, but I find them to still be poor at the outer most couple of inches on both ends of the blade.

[Fast4esT]

pumps are the same from what I gather from B6 to B8, my pumped looked clean, no sings of leakage from the sprayer

im just miffed that the wiper worked for a moment with the hatch open, really made me believe the wire break was back there