Engine light fault code P0479

gmacd78

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Hi Guys,

Im 3k miles into my 2020 GS1250 Rallye ownership. All going well until today when my engine check light illuminated when taking off.

Scanned it with Torque Pro which I use for cars and it came back with P0479

https://www.obd-codes.com/p0479

This code relates to Exhaust pressure control valve in a car so guessing it's the butterfly valve in the exhaust that's faulty/sticky/dirty? I'm nowhere near a BMW garage so anything I can try in the mean time to fix this?

I reset the code, engine light illumination went off but comes back after a couple of starts. No limp mode or restricted performance, goes just like it always has.

Any ideas gents?

Cheers
 
Leave it,


tamper at you peril ( warranty)

The valve is noise & emissions,

just get tt back to the dealer who will replace the zorst
 
Are these exhaust valves known to fail on the 1250 with so little miles? What is it that fails on them, mechanical or electrical?
Cheers
 
Are these exhaust valves known to fail on the 1250 with so little miles? What is it that fails on them, mechanical or electrical?
Cheers
It would appear that they fail with monotonous regularity. It seems to be on the whole a mechanical failure of the bearing surface upon which the flap pivots in the heat of the exhaust gases. My 1200 started to squeal as it cycled upon switching on the ignition. New headers installed under warranty.
A friend’s RT has his seized in the open position - it doesn’t register a yellow triangle on the dash fault, but is detectable with a GS-911wifi. The condition may have flashed up a fault if, like your bike, it had a TFT display.
The dealer is your friend in this matter because warranty work is chargeable to BMW so they will be happy to clock up workshop time on BMW’s bill.
Alan R
 
Ok guys thanks for prompt input. I'll get a dealer visit planned in. Poor design if these fails so easily, what's the common fix if out of warranty?
 
Ok guys thanks for prompt input. I'll get a dealer visit planned in. Poor design if these fails so easily, what's the common fix if out of warranty?
It will more than likely seize in the open position. Some reports on this site state that freeing the flap by hand and applying graphite based lubricant works for a while. There is also an electronic device available that can be connected to the servo wiring to fool the bike into believing that the servo is still connected. The now redundant servo, connecting Bowden cables and flap just sit there doing nowt.
Alan R
 
The valve isn't designed to seize until your two months out of warranty or your PCP is about to come to term. But In your case, you'll just get a new exhaust under warranty.

After warranty your local dealer will tell you you need £1000 for new headers and steer you to buy a new bike.

Your touch screen dashboard and shift cam motors will all be failing then too so maybe you will..

Best thing to do is remove the cables when it's it the open (default) position so the electric motor still turns freely letting the computer think everything is fine.

The flaps are for noise and very low rpm back pressure. It's not required or missed by anyone who's removed it.
 
The valve isn't designed to seize until your two months out of warranty or your PCP is about to come to term. But In your case, you'll just get a new exhaust under warranty.

After warranty your local dealer will tell you you need £1000 for new headers and steer you to buy a new bike.

Your touch screen dashboard and shift cam motors will all be failing then too so maybe you will..

Best thing to do is remove the cables when it's it the open (default) position so the electric motor still turns freely letting the computer think everything is fine.

The flaps are for noise and very low rpm back pressure. It's not required or missed by anyone who's removed it.
cynicism aside:rolleyes:
I’m almost sure that the ‘computer’ recognizes that when the servo operates with no flap spring resistance, it sees this as a fault in the same way that it recognizes when the flap is seized.
Alan R
 
cynicism aside:rolleyes:
I’m almost sure that the ‘computer’ recognizes that when the servo operates with no flap spring resistance, it sees this as a fault in the same way that it recognizes when the flap is seized.
Alan R

My dealer said the computer has to sense the 90 degree turn of the valve and a level of resistance, otherwise it throws an error code.
 
Just had my headers on my 2019 RT changed on Saturday, 6k and engine waring light. But did a weekend in Wales before having the exhaust replaced, no issues with the bike at all. Also had two sets of headers on my 2014 under warranty, same thing. Do a search, loads of posts about the flap :)
 
Your dealer is talking bullshit. I was a dealer tech for 8 years. Unless they have changed the servo motor on the latest 1250s then there is no issue whatsoever. I've been de-flapping 1200's for YEARS.

There is no resistance gauge on that motor. It just needs to go from one stop to another on start-up for a self test. BMW dealers are just warranty part fitting centers and most of them haven't got a single clue between them.

Pretty much every set of aftermarket headers for BMW's require you to remove the cables and leave the servo motor attached. Including the race headers sold BY BMW..

If you have been riding with a seized flap for a long time then you can damage the motor. This is where the persistent fault can arise. Because the motor has been damaged by constantly trying to move a seized flap.
 
Your dealer is talking bullshit. I was a dealer tech for 8 years. Unless they have changed the servo motor on the latest 1250s then there is no issue whatsoever. I've been de-flapping 1200's for YEARS.

There is no resistance gauge on that motor. It just needs to go from one stop to another on start-up for a self test. BMW dealers are just warranty part fitting centers and most of them haven't got a single clue between them.

Pretty much every set of aftermarket headers for BMW's require you to remove the cables and leave the servo motor attached. Including the race headers sold BY BMW..

If you have been riding with a seized flap for a long time then you can damage the motor. This is where the persistent fault can arise. Because the motor has been damaged by constantly trying to move a seized flap.

When I bought my -15 GSA second hand, it was equipped with Acra headers and a can(no flap), and the actuator had it's cables removed, but the motor was stil operating. It never showed a malfunction code for the flap.
 


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