"K" Bus problems and the answer!!

Trophy Blue Tourer · 15th August 2012, 17:37

This post is just to follow up on a problem I had last year and the (eventual) solution!

Some might remember I was having K bus problems last summer resulting in the usual drivers door lock faulting/no main beam warning light/no dashboard indicator lights and "error" coming up on the Climate Control panel!!

After a lot of "chasing" possible causes with the help of members on the forum it was eventually traced (more or less by accident

) to the symphony head unit when it was unplugged to access the wiring and header conections located behind it!!

The short term fix was to snip the K bus wire located in the blue/green/yellow composite plug (3 plugs clipped together) attached to the head unit which got rid of the interferance - and the symptoms!! but left the unit unable to talk to the CD changer and control it but did leave the radio and tape player (combined in the head unit of course!!

) still working - This was Ok as a stop gap but didn't really answer the question was it the head unit or the CD player!!

I had had a "gut" feeling all along that it was going to be the head unit but didnt really want to lash out on one if it wasnt a "deffinate"!!

I did have the promise of a couple to try out as subsitutes but sadly they never appeared!!

About a month ago I got fed up/irittated with only having the radio so I brought one from ebay circa £30 delivered and when it arrived tried it out only to find that the code had (unusualy for a symphony) been activated and the supplier didnt have any idea what it might be (probably exspecting a bit much for a breakers TBF!!

)

After a couple of phone calls they apolagised and said they would refund and arrange for pick up!!

- YEH RIGHT!!

that never happened!!

That stalled things a bit untill I noticed a post on the forum about member Xpart02

who will supply a code FOC to subscribed members!! - sadly my subscription had just run out!!

- move on the the end of the month and having resubscribed come payday!

I contacted Stuart who dulely supplied the code for my new head unit and this morning I finally got around to fitting it and hay presto!! everything works again!! with no faults either in the head unit OR the CD player (Phew!!

)

So if you get the above symptoms and unpluging the FBH or the imobiliser doesn't help !! try the radio!!

HTH well somebody!!

Petetourer · 15th August 2012, 17:49

Good to hear it soreted the problem mate.....

Now, onto your next project...

Mike Noc · 15th August 2012, 21:46

Good work Andy. That's the problem with bus system faults, they can be anywhere in the circuit. TBH that's one of the last places I would have looked.

Mike

BigRuss · 15th August 2012, 22:51

Had exactly those symptoms on a car today but it wasn't that, I checked and no joy tried all other accessable K-bus points including all most of the Ecu's.

I think I know where the problem lies it's likely to be the K109 K-bus header beneath the carpet as the foam was sodden but without more time and dry weather I was unable to confirm.

Russ

Trophy Blue Tourer · 15th August 2012, 23:38

Quote:

Originally Posted by Mike Noc

Good work Andy. That's the problem with bus system faults, they can be anywhere in the circuit. TBH that's one of the last places I would have looked.

Mike

To be fair Mike!! It WAS the last place I looked!!

In fact I didnt actually look there! - what happened was that chrislloydie and I had removed both wheel arch liners to check for chaffed looms etc and I had not found anything other than both looms had lost most of their wrapping at the point where they split to go in 3 different directions and as I was re-wrapping them in self-amalagamating tape I got Chris to strip the C/C and radio out so we could check the headers etc behind them!! after we had opened them (headers) and reassembled them we realised the fault had gone so assumed that we had disturbed a bad conection!! - It wasnt until after Chris had left and I was reasemballing the center console that I noticed it had come back!!

so I started pulling plugs with the indicators on and flashing on the dash until they stopped and found the fault!!

- just sort of tripped over it really!!

Quote:

Originally Posted by BigRuss

Had exactly those symptoms on a car today but it wasn't that, I checked and no joy tried all other accessable K-bus points including all most of the Ecu's.

I think I know where the problem lies it's likely to be the K109 K-bus header beneath the carpet as the foam was sodden but without more time and dry weather I was unable to confirm.

Russ

Sounds likely Russ!! there not very water proof!!

- I just wanted to record another potential cause (even if its a bit of a rarity!!) for future seakers after the truth!!

Andy!!

P.S!! found a very enjoyable "classic music" tape in my new head unit too!! - "every little helps""

sworks · 16th August 2012, 06:17

Good to hear your finally sorted, I have the same fault albeit very random when it occurs. I have checked the radio etc after reading your origional thread. I will have to have a look for K109 header beneath the carpet Russ? I have allready checked the one above the LSM

Reebs · 16th August 2012, 06:50

The radio on my highline in the ZT-T wouldn't come on in a similar fashion, but after discovering a small lake under the front drivers side carpet due to a blocked plenum drain tube, the radio corrected itself back to full operation once it was all dried out. The shorting out of the header might explain it. It's always good to hear a follow up solution to a problem, thanks for posting your findings Trophy Blue

Trophy Blue Tourer · 16th August 2012, 10:53

WRONG WRONG WRONG!!!
so I started pulling plugs with the indicators on and flashing on the dash until they stopped and found the fault!!WRONG!!

IT SHOULD HAVE READ!!

so I started pulling plugs with the indicators on and ** NOT** flashing on the dash until they **STARTED** and found the fault!!

Doh!!

Still I dont feel to bad !!

You lot didnt spot it either!!

Andy

craig8661 · 16th August 2012, 12:21

Quote:

Originally Posted by BigRuss

Had exactly those symptoms on a car today but it wasn't that, I checked and no joy tried all other accessable K-bus points including all most of the Ecu's.

I think I know where the problem lies it's likely to be the K109 K-bus header beneath the carpet as the foam was sodden but without more time and dry weather I was unable to confirm.

Russ

Where is that's part fitted as mine the other week wipers would not work in drive and also ipk mpg screen stopped working climet would not change any settings would only make the noise to say a button has been pressed. Then next day same faults but Speedo was not working but abs was. Is that unit you refer to the body controls unit. I also have the symphony head unit think it is any was has the big power button and large display. My faults have gone it had been raining very heavy plenams where clear but passinger side carpet is wet

beinet1 · 5th November 2012, 08:43

Quote:

Originally Posted by BigRuss

Had exactly those symptoms on a car today but it wasn't that, I checked and no joy tried all other accessable K-bus points including all most of the Ecu's.

I think I know where the problem lies it's likely to be the K109 K-bus header beneath the carpet as the foam was sodden but without more time and dry weather I was unable to confirm.

Russ

Hi all,

Can anyone tell me excactly how it looks ad where this K109 connector is located?? My car is a LHD, but I think it is only "mirrored" compared to the RHD one`s.

I an dealing with a central locking issue, and I know somewone has found the problem in this connector due to corrosion.

Is there any other K-bus connectors in sthe system that may cause central locking issues??

15th August 2012, 17:37	#1
Trophy Blue Tourer Gets stuck in MG ZT-T Trophy Blue CDTI Join Date: Feb 2011 Location: Milton Keynes Posts: 883 Thanks: 11 Thanked 25 Times in 18 Posts	"K" Bus problems and the answer!! This post is just to follow up on a problem I had last year and the (eventual) solution! Some might remember I was having K bus problems last summer resulting in the usual drivers door lock faulting/no main beam warning light/no dashboard indicator lights and "error" coming up on the Climate Control panel!! After a lot of "chasing" possible causes with the help of members on the forum it was eventually traced (more or less by accident) to the symphony head unit when it was unplugged to access the wiring and header conections located behind it!! The short term fix was to snip the K bus wire located in the blue/green/yellow composite plug (3 plugs clipped together) attached to the head unit which got rid of the interferance - and the symptoms!! but left the unit unable to talk to the CD changer and control it but did leave the radio and tape player (combined in the head unit of course!!) still working - This was Ok as a stop gap but didn't really answer the question was it the head unit or the CD player!! I had had a "gut" feeling all along that it was going to be the head unit but didnt really want to lash out on one if it wasnt a "deffinate"!! I did have the promise of a couple to try out as subsitutes but sadly they never appeared!! About a month ago I got fed up/irittated with only having the radio so I brought one from ebay circa £30 delivered and when it arrived tried it out only to find that the code had (unusualy for a symphony) been activated and the supplier didnt have any idea what it might be (probably exspecting a bit much for a breakers TBF!!) After a couple of phone calls they apolagised and said they would refund and arrange for pick up!! - YEH RIGHT!! that never happened!! That stalled things a bit untill I noticed a post on the forum about member Xpart02 who will supply a code FOC to subscribed members!! - sadly my subscription had just run out!! - move on the the end of the month and having resubscribed come payday! I contacted Stuart who dulely supplied the code for my new head unit and this morning I finally got around to fitting it and hay presto!! everything works again!! with no faults either in the head unit OR the CD player (Phew!!) So if you get the above symptoms and unpluging the FBH or the imobiliser doesn't help !! try the radio!! HTH well somebody!!

15th August 2012, 17:49	#2
Petetourer This is my second home None at present Join Date: Sep 2010 Location: Portishead Posts: 5,337 Thanks: 203 Thanked 246 Times in 194 Posts	Good to hear it soreted the problem mate..... Now, onto your next project... __________________ My First Ever Rover!! A 2002 75 2.0 V6 Club SE Tourer Then a 2002 MG ZT-T CDTI + in Starlight Silver Then a 2003 ZT-T 2.5 V6 180 + in Royal Blue Then a 2002 Rover 75 2.0 CDTi Connie SE Then a 2003 ZT-T 2.0 CDTi + In Le Mans Green 2004 1.8T ZT-T + In Goodwood Green [SIGPIC][/SIGPIC]

15th August 2012, 22:51	#4
BigRuss Premium Trader 75 CDT Tourer,2.5 Launch Saloon, Omipro MG/Rover (T4) Join Date: Jul 2007 Location: Liversedge, West Yorkshire Posts: 5,416 Thanks: 1,105 Thanked 1,340 Times in 661 Posts	Had exactly those symptoms on a car today but it wasn't that, I checked and no joy tried all other accessable K-bus points including all most of the Ecu's. I think I know where the problem lies it's likely to be the K109 K-bus header beneath the carpet as the foam was sodden but without more time and dry weather I was unable to confirm. Russ __________________ Replacement Key Service http://https://the75andztclub.co.uk/...d.php?t=244732 Full T4 Testbook diagnostics available. Diesel ECU repair and replacement. Options enabled or disabled as required. Diesel X-Power 135 and "160", Rover 1.8T 150 to 160 MG 160 V6 to 177 upgrades available P.M. for details.

16th August 2012, 06:17	#6
sworks This is my second home Rover 75 Tourer, Classic mini Cooper S, Abarth 595 competizione, MG TF and a Hyundai Tucson PHEV Join Date: Feb 2007 Location: Cumbria Posts: 13,080 Thanks: 1,033 Thanked 1,686 Times in 1,040 Posts	Good to hear your finally sorted, I have the same fault albeit very random when it occurs. I have checked the radio etc after reading your origional thread. I will have to have a look for K109 header beneath the carpet Russ? I have allready checked the one above the LSM __________________ ................................................. 'Marmite' Possibly one of the most famous 75 tourers produced! left the production line as the last of only Three Rover 75 tourers produced in Trophy Yellow. 48 hours later Longbridge closed. The last sold ordered 75 Tourer. Paid for by the Phoenix Four and handed over by John Towers to the Warwickshire Northampton Air ambulance service as a Rapid Response vehicle

16th August 2012, 06:50	#7
Reebs Owners Club Director Rover 75 Conn SE V6 / MG ZT 260 SE V8 / MG ZT 180 SE V6 Join Date: Feb 2007 Location: Southampton Posts: 20,967 Thanks: 645 Thanked 6,851 Times in 2,537 Posts	The radio on my highline in the ZT-T wouldn't come on in a similar fashion, but after discovering a small lake under the front drivers side carpet due to a blocked plenum drain tube, the radio corrected itself back to full operation once it was all dried out. The shorting out of the header might explain it. It's always good to hear a follow up solution to a problem, thanks for posting your findings Trophy Blue __________________ Check your trim here . Check your spec here Check your colour here . Check Project Drive here Check your original price here

15th August 2012, 21:46	#3
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,579 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Good work Andy. That's the problem with bus system faults, they can be anywhere in the circuit. TBH that's one of the last places I would have looked. Mike

16th August 2012, 10:53	#8
Trophy Blue Tourer Gets stuck in MG ZT-T Trophy Blue CDTI Join Date: Feb 2011 Location: Milton Keynes Posts: 883 Thanks: 11 Thanked 25 Times in 18 Posts	Opps!! WRONG WRONG WRONG!!! so I started pulling plugs with the indicators on and flashing on the dash until they stopped and found the fault!!WRONG!! IT SHOULD HAVE READ!! so I started pulling plugs with the indicators on and NOT flashing on the dash until they STARTED and found the fault!! Doh!! Still I dont feel to bad !! You lot didnt spot it either!! Andy