Start/Stop Button "Press Clutch to Start Engine" Problem

[sh!tmagnet]

So I subscribed to AllDataDIY (FYI used discount code renewDIY and you get 2 years for $12.95), and this is what I've found.

I've tried searching around for this Clutch Position Sensor, G476, but I haven't turned it up anywhere yet. May call the stealership and see if they have it listed for the B8s.

M/T - No Start Or Only Starts When Clutch Firmly Applied

30 Vehicle does not start or only starts when the clutch pedal is pressed very firmly
30 13 18
2028229/2
June 13, 2013
Supersedes Technical Service Bulletin Group 30 number 11-11 dated December 9, 2011 for reasons listed below.


Vehicle Information


Condition
^Customer may report that the vehicle does not start or only starts when the clutch pedal is pressed very firmly.
^The message "Press clutch pedal to start vehicle" may appear in the instrument cluster.
Technical Background
There may be clutch mechanism wear.
Production Solution
Not applicable.
Service
1.Check the clutch hydraulics and electrics as follows:
2.Depress the clutch pedal to the perceived end stop.
While the clutch pedal is depressed, have a second technician open the bleeder screw on the clutch slave cylinder.
^If the clutch pedal can now be moved further and the vehicle can be started, or if the message in the instrument cluster goes out, the sender of the clutch mechanism is correct. The issue is clutch mechanism wear; see the ElsaWeb Repair Manual for instructions. Do not replace the clutch master cylinder or slave cylinder, as doing so will not resolve this condition.
^If the clutch pedal still cannot be moved further, or if the message in the instrument cluster does not go out, check the operation of the Clutch Position Sensor -G476-.
3.Close the bleeder screw on the clutch slave cylinder.
Warranty
This TSB is informational only and not applicable to any Audi warranty.
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.

[Legacykid]

Update on mine, The issue is offically back. At time i have to fred flintstone the pedal to get the car started. Its going in for service tomorrow. 55k miles I wonder if they will blame the clutch, because they mentioned it on the phone before I said i was only at 55k.

[sh!tmagnet]

I've just been giving it a little extra hard push lately and it hasn't really acted up that much. I plan to try the slave bleed to see if that helps(just been too damn busy lately). It wouldn't surprise me that they effed things up and got air in the system when I had the 45k service at Barrier in Seattle. Was disappointed with they're shody service overall.

[Legacykid]

Such a stupid thing to have to worry about on a car like this.

[infinkc]

Update on mine, The issue is offically back. At time i have to fred flintstone the pedal to get the car started. Its going in for service tomorrow. 55k miles I wonder if they will blame the clutch, because they mentioned it on the phone before I said i was only at 55k.

i did further digging into the issue as its the same as yours and there is another member also with the same issue.

The clutch master is comprised of 3 switches in it!

there is the F36 Clutch Pedal Switch that is used for cruise control
there is the F194 Clutch pedal switch that triggers the "Press Pedal to start" part of the car
there is the G476 Clutch position sender which from my understanding measures how worn the clutch is by the amount of fluid passing through the master.

If anyone has further info on the G476 and how it operates, i would like to know as that is the problem my car has.

You can use a Vagcom to measure the blocks of both the switches. its block 265(F194), starter control clutch switch and block 266(G476) starter control, interlock switch (may be a few numbers different depending on what version vag you have loaded)

The last bit will change to a 1 when active.

Both need to be "1" for the car to start.

If you felt like bypassing the switch you can simply ground out the wire in the ecu box that gets triggered. blue gray is the F194 and green/gray is the G476. I haven't had time to physically measure the voltages at the wires yet.

I will be interested in what Audi finds on your car. All the posts i read, the clutch is the final answer.

[Legacykid]

i did further digging into the issue as its the same as yours and there is another member also with the same issue.

The clutch master is comprised of 3 switches in it!

there is the F36 Clutch Pedal Switch that is used for cruise control
there is the F194 Clutch pedal switch that triggers the "Press Pedal to start" part of the car
there is the G476 Clutch position sender which from my understanding measures how worn the clutch is by the amount of fluid passing through the master.

If anyone has further info on the G476 and how it operates, i would like to know as that is the problem my car has.

You can use a Vagcom to measure the blocks of both the switches. its block 265(F194), starter control clutch switch and block 266(G476) starter control, interlock switch (may be a few numbers different depending on what version vag you have loaded)

The last bit will change to a 1 when active.

Both need to be "1" for the car to start.

If you felt like bypassing the switch you can simply ground out the wire in the ecu box that gets triggered. blue gray is the F194 and green/gray is the G476. I haven't had time to physically measure the voltages at the wires yet.

I will be interested in what Audi finds on your car. All the posts i read, the clutch is the final answer.

Good to know

Dropped of this morning, the dealerships tune changed once i got there. It went from yeah bring it in, its happened before and they have a TSB for it warranty doesn't matter. To Its coming out of my pocket. So If that is the case Im going to call AOA.

[sh!tmagnet]

Good to know

Dropped of this morning, the dealerships tune changed once i got there. It went from yeah bring it in, its happened before and they have a TSB for it warranty doesn't matter. To Its coming out of my pocket. So If that is the case Im going to call AOA.

So any update, what happened?

[Legacykid]

So any update, what happened?

They ended up covering the repair. looks like they removed the clutch fork and replaced with updated one, also replaced fork pivot point and bearing. have not driven it much, but one of the times it did hesitate. will report back when i use it more.

[Legacykid]

So it has occurred 2 times since i have come back to the dealer randomly. idk what the issue could be

[boss2k]

happened with me today, car has 15k miles, what could the issue be?

[Legacykid]

Last time it was fixed for quite some time was when they replace the whole assembly. Fork and clutch master cyl. Because it's happening again

[salmjo1]

Add another to the list.
55k miles (out of warranty)
Car drives as it always has, no difference in feel of clutch.
Have to stand on the pedal to get it to start. Interestingly, it does not say "depress clutch to start car", which makes me think it's the G476 clutch position sensor switch not kicking to "1".

Sounds like the order of service is: bleed system; check function of both switches;
would be great to know how to use G476 to test clutch wear. I hate to tear it apart for nothing.
Of course if it is the clutch, I am (1) going to teach my 16 yo to drive on the thing now and then (2) upgrade the clutch and go to AWE/GIAC pulley and tune.

[MisterB8er]

I had my clutch replaced at 55k with a JHM stage 3 with flywheel. I forget the term they used to describe the problem that prompted the replacement, but basically if comes from shifting to too low of a gear at too high of speed. Overspin, or something, idk.

From shortly after getting the new clutch until now (66k) I have had to depress the clutch extra hard to get the car to start. I'm pretty sure this was not the case before the new clutch as that would probably would have kept me from buying the car. I have since taken it back to the shop that installed the new clutch and they attempted the master cylinder bleed option to no success. They plan to call JHM for advice. With that said it is hard to believe that clutch wear is the issue here since this was happening from installation of the brand new clutch.

I doubt that the clutch fork is the issue since it didn't solve legacy kids issue.

I think I will ask my shop if they did anything with the throw out bearing when installing the new clutch, as that seems to be a commonly mentioned factor in all these threads I'm reading.

[Legacykid]

Mine is acting up real bad again. Dreading bring it back in yet again for another issue. I feel like they will just blame the clutch.

[sh!tmagnet]

So legacykid, is there any components in there that they haven't replaced? You said they replaced your master cylinder at one point, so I would assume its not a faulty G476 switch.

As a thought, did they bleed the system properly by elevating the rear of the car sightly?

Another thought, is there anyway to permanently assign a 1 to the G476 reading using VAGCOM. Essentially bypassing the switch through the software?

[sh!tmagnet]

Forgot to mention, I'm going to be doing my Eurocode clutch kit here soon. Wondering if there's anything else I should consider replacing while I'm in there?

[Legacykid]

So legacykid, is there any components in there that they haven't replaced? You said they replaced your master cylinder at one point, so I would assume its not a faulty G476 switch.

As a thought, did they bleed the system properly by elevating the rear of the car sightly?

Another thought, is there anyway to permanently assign a 1 to the G476 reading using VAGCOM. Essentially bypassing the switch through the software?

I do not know if they bled the system in that manner or not. They have replaced a lot, hopefully at the end of the week or next I will bring it in.

Idk about the Vag Com, i do not have one but Id be curious if anyone else could check that out.

[pairadocs]

Mine is doing it too.

At first i thought i wasn't pushing the clutch down far enough - which would be weird since i been driving a manual car for almost 30 years.

What i have noticed is that it does the needle sweep/no start moreso when the car is cold/been sitting/not driven - like first thing in the morning i go get in it and have to double press - always starts on the 2nd try.

second weird thing i noticed, again with car relatively cold/recently started - i pull up to a red light, clutch pedal NOT pushed in, car not in gear - then i push in clutch and put car in 1st gear and get ready to go and i hear my engine rev up a little (AWE exhaust, so easier to hear this) - i look down at the tachometer and the needle is sitting at 1250 RPM, instead of the usual idle around 750 RPM.

I dunno whats wrong. my car only has 31000 miles, and not tracked and not riden hard or rough, and clutch feels good otherwise. mine is scheduled into the stealer on may 1st.

anyone else with the double clutch press to start car issue also have the RPMs up a little? anyone else notice it more when the car is cold/sat for a while?

[boss2k]

After 9 months i got the issue again last friday for few mins . Initially when i had reported the issue dealer bled the clutch and things were fine.

Any clue how to fix this damn message ?

[footbllpro30]

Mine is doing it too.

At first i thought i wasn't pushing the clutch down far enough - which would be weird since i been driving a manual car for almost 30 years.

What i have noticed is that it does the needle sweep/no start moreso when the car is cold/been sitting/not driven - like first thing in the morning i go get in it and have to double press - always starts on the 2nd try.

second weird thing i noticed, again with car relatively cold/recently started - i pull up to a red light, clutch pedal NOT pushed in, car not in gear - then i push in clutch and put car in 1st gear and get ready to go and i hear my engine rev up a little (AWE exhaust, so easier to hear this) - i look down at the tachometer and the needle is sitting at 1250 RPM, instead of the usual idle around 750 RPM.

I dunno whats wrong. my car only has 31000 miles, and not tracked and not riden hard or rough, and clutch feels good otherwise. mine is scheduled into the stealer on may 1st.

anyone else with the double clutch press to start car issue also have the RPMs up a little? anyone else notice it more when the car is cold/sat for a while?

Another one to add to this list. I am having the same issue of having to press the clutch pedal very hard to get the car started. It comes up saying "depress clutch to start car". If I press hard enough it will start. I also had the exact same issue as you pairadocs where I was sitting at a red light and my engine reved up to 1250 RPMS without pressing on gas. I have seen this issue numerous times. I took it in for service and they replaced the Throttle Body and it seemed to lessen the frequency of the issue, although I have seen it about 1 time in 5 months since them. Before the replacement of the Throttle Body, it was doing it almost every day.

I took my car to a shop here in town and they followed TSB 2028229/2 (as listed above on this page). After they did the bleed test, the issue seems to be partially resolved. It still requires about 10% more force on the pedal to start but no where near as bad as it was before. So this is encouraging in some ways.

I have my car going into Audi tomorrow to see if they will cover whatever the issue is under warranty. I will post my results once they diagnose. This whole issue has been extremely frustrating since my car only has 23K miles on it.

[S4'ed]

Same problem here.....
http://www.audizine.com/forum/showth...feature-glitch

[S4'ed]

So, here is a fix idea:
From pictures of the clutch master cylinder, it looks like is has a rubber gasket (grey ring on black cylinder body) between it and the firewall (on the engine compartment side). If you remove the gasket, or use a thinner one, then the master cylinder internal piston will be moved a little further into the bore when the clutch pedal is fully depressed, which might be the extra 3 or 5mm needed to get the start-switch to trip.

Maybe remove the gasket and use some RTV to seal against water entry....if it doesn't work it is easily reversible.

https://www.ecstuning.com/Audi-B8_S4...lic/ES2832727/

[sh!tmagnet]

Update: I know I started this thread and then disappeared, but that's what has happened for the last 6-8 months. Either muscle memory is pushing the pedal harder and I'm not noticing or the problem just went away. I know that doesn't help give a definitive answer. But its been fine for a while. I even installed the USP clutch line and its still starting fine.

Now I just had an idea, maybe that delay valve that the USP line bypasses could help remedy this issue?

[sh!tmagnet]

As a side note, when I was in changing this line out, the "sensor" on the clutch master cylinder can actually unclip (not the wiring but the actual sensor) from the master cylinder even though Audi doesn't sell it separately, or list it as a separate part.

[footbllpro30]

So, here is a fix idea:
From pictures of the clutch master cylinder, it looks like is has a rubber gasket (grey ring on black cylinder body) between it and the firewall (on the engine compartment side). If you remove the gasket, or use a thinner one, then the master cylinder internal piston will be moved a little further into the bore when the clutch pedal is fully depressed, which might be the extra 3 or 5mm needed to get the start-switch to trip.

Maybe remove the gasket and use some RTV to seal against water entry....if it doesn't work it is easily reversible.

https://www.ecstuning.com/Audi-B8_S4...lic/ES2832727/

The link to ECS tuning does not work. Can you provide some more detail as to how I could try this fix? I would like to try it on my S5. It would be great if I could fix a fix instead of replacing the clutch since that's what Audi says is the issue.

[E.Anderson]

I just got a brand new clutch master cylinder from the dealer under CPO. Even before my car left the dealer they told me that this is not resolved the issue and the next step would be to replace the clutch @ $5,100

I was also given the option of taking a gamble, paying them 15 hours of labor @ $155/hr to inspect the transmission and figure out if the issue is or isn't clutch related. Really something that shouldn't be the onus of the customer

[S4'ed]

The link to ECS tuning does not work. Can you provide some more detail as to how I could try this fix? I would like to try it on my S5. It would be great if I could fix a fix instead of replacing the clutch since that's what Audi says is the issue.

I am not sure how to give you any more detail on how try this.......but it might go something like this:
Under the dash, remove the cylinder endlink from the clutch pedal, then remove the U clip (?) that holds the cylinder to the firewall. In the engine compartment, pull the cylinder forward, out of the mounting hole, and remove the rubber washer, then re-install in reverse order.

As for the link, goto ECStuning.com, enter your car info as a Audi S4 B8, select drivetrain, then clutch, hydraulics, and select the master cylinder to look at the picture......

[S4_V6T]

Mine is doing it too.

At first i thought i wasn't pushing the clutch down far enough - which would be weird since i been driving a manual car for almost 30 years.

What i have noticed is that it does the needle sweep/no start moreso when the car is cold/been sitting/not driven - like first thing in the morning i go get in it and have to double press - always starts on the 2nd try.

second weird thing i noticed, again with car relatively cold/recently started - i pull up to a red light, clutch pedal NOT pushed in, car not in gear - then i push in clutch and put car in 1st gear and get ready to go and i hear my engine rev up a little (AWE exhaust, so easier to hear this) - i look down at the tachometer and the needle is sitting at 1250 RPM, instead of the usual idle around 750 RPM.

I dunno whats wrong. my car only has 31000 miles, and not tracked and not riden hard or rough, and clutch feels good otherwise. mine is scheduled into the stealer on may 1st.

anyone else with the double clutch press to start car issue also have the RPMs up a little? anyone else notice it more when the car is cold/sat for a while?

Have you had your car tuned? It may be the cold start feature that is raising your RPMs. With regards to the clutch pedal issue from personal experience of having the transmission out 3 times now I would say that it is the clutch fork that was the main culprit for me each time. I did replace the clutch and added a LWFW for good measures as well and have change the master slave twice also.
It seems like the clutch fork bent twice for me and was causing the issue of the clutch pedal failing to register being depressed and I really needed to put a lot of pressure to start the car. This in turn killed a couple of master slaves.
So far so good for the last install but I am just waiting for it to go again!

[Ze_Nardo6]

I am getting the same error 600 miles after having a Eurocode stageIII clutch and LWFW installed. It says engage clutch to start engine and I practically have my foot through the floor. Still no luck.

To all who have had this issue, what has remedied the situation? New clutch fork, master slave, or simply the sensor?

[S4'ed]

I don't think there is a permanent "fix" for this yet from Audi engineering, but see my proposed fix in above posts #62 and #67.

[Ze_Nardo6]

thanks!

[jimrobbington]

I am getting the same error 600 miles after having a Eurocode stageIII clutch and LWFW installed. It says engage clutch to start engine and I practically have my foot through the floor. Still no luck.

To all who have had this issue, what has remedied the situation? New clutch fork, master slave, or simply the sensor?

Same here. Brand new JHM stage 3 clutch and lwfw, 300 miles later, won't start unless I stand on the clutch pedal. Dealer immediately wanted to blame the new aftermarket parts that THEY installed. I'm hoping to get into a REAL shop soon and get it taken care of, but from what I've read, it's master cylinder.

[E.Anderson]

I had my master cylinder replaced at the dealer. It has only been 2 days but I haven't reproduced the problem....yet

[infinkc]

I had my master cylinder replaced at the dealer. It has only been 2 days but I haven't reproduced the problem....yet

xing fingers, i think im going to change mine out soon also. I wonder what downsides bypassing the switch would actually do, since there is the secondary switch still that wont allow the car to start.

[E.Anderson]

Although this has made the issue less pronounced, it has not completely fixed it. I don't have to press as hard as before, but I will still get the warning (especially when it's cold). Unfortunately i'm not going to pay for a new clutch at this time so I will just deal with it until it's time for a new one.....Or sell the car

[S4'ed]

Anybody want to sell me your old master cylinder? I will paypal you $20 to ship it to me.

[DGVR6]

I'm actually have the same problem, when I pulled codes out I got the same exact one.
Both key and car battery are new.. Doubt it's the key..

I guess the problem is still unknown ..

[Thurston]

Well I guess I won't be upgrading my clutch anytime soon until the cause of this little issue is figured out - I'm sure it will happen to me as well.

[F16HTON]

There are a couple of things that are going on that can contribute to the issue. Let me explain how the switch works, there is a plunger inside the master cylinder that has a magnet on it, the master cylinder in itself has three separate switches on it (as described earlier) which are activated when the magnet passes across the switch. I do not know that exact reason for failures, however I suspect that it is either

1.) The fluid in the circuit has air in it and is not allowing the plunger to move far enough to activate the switch or
2.) the magnet becomes weak and is no longer able to trigger the switch

You could try to do a full bleed of the clutch and remove all of the air out of the system, a vacuum bleed typically works best, or you can replace the clutch master cylinder. There is the possibility that the clutch master cylinder piston can have a bad seal too, this scenario will may keep the plunger from moving all of the way.

[Ze_Nardo6]

Replacing the master cylinder remedied the problem for me.