Error C28

[Notty]

Thanks Snapey, she has already paid an *expert* to clean etc - he said its a common fault and needs a new part !! she has got hold of some throttle bodies complete as this is the easiest and cheapest way . Thanks for all the advice guys 

I hope she doesn't leave the throttle bodies with the expert as he'll fix them & sell on Ebay. If she doesn't want them I'm sure someone on here would enjoy pulling it all apart & fixing the offending STVA. While it's in pieces I like to flush the injectors too.

You guessed Snapey - the deal she has done is to have the replacement bodies and if they work £160 and he keeps the old ones  -as she can't do f..k all herself she has to pay her *expert* to fit them - FFS I told her she was a silly cow 
@Snapey @seth

[Snapey]

I suppose if the "expert" is running a business he has to make a quid somehow. Mind you, removing & replacing the throttle bodies is a prick of a job best left to those who know what they're doing but my tip with the sheet metal helps there to keep the rubbers in shape.

[Hooli]

Is it? I don't recall much hassle doing it, I've done a lot worse jobs on other things.

[KiwiCol]

I bet the 'expert' glues up her ones & charges her 160 for the replacements & labour to fit etc.

[seth]

If it gets her bike sorted all good but if he's taking a lend of her when he could just reglue her ones and refit them it's not right.
He might well just remove reglue and refit hers so tell her to mark them to make sure she's getting replacements .
It's always a problem when you can't do the work your a bit at the mercy of someone who can .

[Snapey]

Is it? I don't recall much hassle doing it, I've done a lot worse jobs on other things.

I find the air box doesn't go back far enough & without a couple of bits of sheet steel to aid removal then the rubbers & clamps can get distorted.

[Hooli]

I must just have the knack of it then.

[Notty]

Update - replacement throttle bodies including sensors fitted and still error 28 bike still ticking over at  2-2.500 . Advised her to get multi plugs,ecu etc  disconnected and use contact cleaner - (tip from Desert Fox, Scot could be battery?) - watch this space 
@seth @Snapey

[Blubber]

Have you cleaned the contacts in the ignition switch?

That might solve some mystery errors....
My k2 had errors related to the chip reader / keycode.  Cleaned the inside of my switch and I am error free....since 2017.

[Hooli]

Have you cleaned the contacts in the ignition switch?

That might solve some mystery errors....
My k2 had errors related to the chip reader / keycode.  Cleaned the inside of my switch and I am error free....since 2017.

What chip reader? UK bikes didn't get the chip in the key until K5.

[Hooli]

Update - replacement throttle bodies including sensors fitted and still error 28 bike still ticking over at  2-2.500 . Advised her to get multi plugs,ecu etc  disconnected and use contact cleaner - (tip from Desert Fox, Scot could be battery?) - watch this space 
@seth @Snapey

The big grey multiplug under the LH cover & ECU multiplug is where I'd start. I'm pretty sure that's where the STVA plugs into the loom.

[Blubber]

Have you cleaned the contacts in the ignition switch?

That might solve some mystery errors....
My k2 had errors related to the chip reader / keycode.  Cleaned the inside of my switch and I am error free....since 2017.

What chip reader? UK bikes didn't get the chip in the key until K5.

Thats my point...My k2 neither 

[Notty]

Update - replacement throttle bodies including sensors fitted and still error 28 bike still ticking over at  2-2.500 . Advised her to get multi plugs,ecu etc  disconnected and use contact cleaner - (tip from Desert Fox, Scot could be battery?) - watch this space 
@seth @Snapey

The big grey multiplug under the LH cover & ECU multiplug is where I'd start. I'm pretty sure that's where the STVA plugs into the loom.

Cheers Hooli - I did tell her to do this weeks ago but hey ho ..will tell her again 

[seth]

After what's been tried and said I'd go with a dodgy connection somewhere too .
As blubber says the lower half of the ignition switch is a common place for corrosion as from experience Suzuki didn't use much grease to protect the electrical connectors from damp getting in.
The big multi plug is also common as hooli has said.
The parts on these bikes only go faulty occasionally and are fairly well documented .
The biggest problem is connectors and our damp cold weather.

[Andre]

This is how it can go:

Ive got a STPS issue as well. 

Here is part of the conversation with the mechanic.

"I have removed your secondary plates but the shaft has to stay. Yours goes through all the right motions, doesn't get stuck
The mechanic has replaced the STPS and the STVA even though my old ones tested ok. Also tried with butterfly paddles removed, no difference.
I have have even removed the plenum to take it back to a STD bike and still have the error, Checked the side stand switch, check valve added, wiring harness checked, changed out throttle bodies with a different motor. I'm trying the same guy to see if i can get a complete ecu and dash setup to try. We have tested the wiring, The pins at the ECU, even replaced a set of throttle bodies with all the sensors from a running bike with out the issue, tested the resistance of your secondary motor through its cycle and it tests ok.
we have tested the wiring, ecu and the STVA, every things seems to work and is adjusted as per the factory specs. it just as soon as the stva operates we get the error,"

Sent ECU to Holland for fault diagnosis, repair and tested ok.

Everything operates as it should. STVA actuates at start up and moves as engine warms up but the STPS still throws up an error code.

He has run out of things to test.

Any thoughts @alfadave ?  He even disconnected the Supercharger and set back to standard. It's only been 5 months off the road 

The Good news is they found a broken wire in the harness between the Intake Air temp sensor and the map sensor. No more FI fault codes. Yippee!

I assume the above was a C29, but it was posted in a C28 thread.

Connectors and wires, even those that are not EFI-related need to be checked. Seem to remember that one had a faulty fan switch (or its wires) but can't serve with a quote/source.