FordMPV Forum

Large MPVs -- Ford Galaxy / VW Sharan / SEAT Alhambra: => Ford Galaxy / VW Sharan / SEAT Alhambra => Topic started by: starg8 on April 02, 2015, 10:37:15 PM

Title: location of ecu (engine) on Mk1 sharan tdi
Post by: starg8 on April 02, 2015, 10:37:15 PM
Hi all
I hope someone can help with this, I am trying to locate the engine ecu on my 2000 mki sharan tdi 110. Is it located in the engine bay on the inner wing next to the battery?

I am currently attempting to trace the cause of several intermittent faults which cumulatively put the vehicle into limp mode, so I intend to check the connections and earthing to the ecu and replace relay 109. I have checked and cleaned all fuses in the main fuse box.

Any advice that can be offered will be gratefully received.

Many thanks

Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: Chrispb on April 03, 2015, 12:57:48 AM
Hi Merv
To get to the engine ECU you need to remove the instrument cluster.
The ECU on the wing panel is for the automatic transmission.
Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: starg8 on April 03, 2015, 09:46:22 AM
Thanks for  clarifying that Chris, I will continue with my investigations.

Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: marinabrid on April 03, 2015, 10:39:47 AM
have you done a code read with vcds vagcom ?
Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: starg8 on April 03, 2015, 02:50:21 PM
Hi Martin

I have done a diagnostic with vcds and previously reset fault codes, too many to list right now and I can't lay my hands on the print out at the moment.

After a short journey the car goes into limp mode, the underlying factor that seems to apply to a majority of the fault codes is that the faults show up as intermittent. This is why I am trying to check all electrical connections on the basis that there may be a dodgy earth or fluctuation in the positive side of the supply to the ecu ( i:e relay 109). Just looking for the simple stuff first.

When I track down the fault code print out, I will post them on here, currently unable to do another scan as the battery is off the car and fusebox hanging in bits awaiting the arrival of replacement relay 109.

Many thanks for your input.

Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: Chrispb on April 03, 2015, 03:03:17 PM
Always handy to keep previous print outs from a scan even if they don't seem relevant to your current problem some may even be years old if not been done recently.
Not surprisingly most fault codes come up as intermittent.
No harm in looking at the ECU there have been instances of chaffing behind the dash that has caused problems in the past but as you can see from the email I sent you it's not that easy but is doable.
Will be interested to see your codes when you have your 109 in place.
Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: starg8 on April 04, 2015, 04:37:42 PM
Hi Chris

I am in total agreement with you regarding keeping print outs for future reference. I hadn't binned them ,just temp. misplaced. Anyway I have recovered them and scanned them (see attachments). I have got fed up with waiting for the replacement relay 109, ordered it from a French online supplier who promised 48hr delivery, that was five days ago. I think they must be using a really slow snail to deliver it.

I have attempted a clean up and resolder of the original 109 relay, when it stops raining I will crack on with it. The car is outside, my garage is only half built, been like that since october last year. French builders are also a nightmare but that's another story.

Back to the fault codes, I have recently removed and cleaned the accelerator pedal unit as this was the first fault to manifest itself after owning the car for around four days. I closely followed the guide in the ref.library. after doing this it seemed ok for a few days then the grief really began. So if you or anyone can shed any further light on a potential solution giving consideration to the faults indicated I would be pleased to receive your input.


Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: Chrispb on April 04, 2015, 11:12:48 PM
Hi Merv
The list of codes you posted are they all recent? by that I mean have you recently cleared any codes then drove the car then rechecked to see whether any have come back

Apart from going into limp mode is any other problems with the car like electric windows and central locking not working

The speedo sensor and engine/transmission connections could be related  a disconnected plug while ignition is on will log a fault.

Airbag possibly broken clockspring

Heated rear window check gaiter to tailgate wiring

Immobiliser warning light check gaiter to drivers door

A/C pressure switch possibly out of gas

Fuel level sensor, is there a problem with the gauge?

Accelerator pedal you have done.

You don't appear to have any boost issues, well no codes anyway.

Relay 109 if it is faulty won't come up with a code, did you find any bad soldering on the old relay?

Once you have the car running again clear all existing codes then recheck after a drive.
Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: starg8 on April 05, 2015, 08:59:51 PM
Hi Chris

Thanks for the pointers, v. useful, today I refitted the 109 relay after it's clean up, I also removed cleaned and refitted the three crimp ring terminals connected to each of the pos & neg battery terminals, replaced one ring term on a v.small csa wire on pos terminal as the original was suffering badly with corrosion at the crimp point. Checked out the gaiter sleeve on drivers door wiring, ensuring that no wires in contact with door and sleeve is securely located.

I cleared all fault codes, took the car for a drive of approx 4 miles then ran a full auto scan with vcds, I am now left with only two of the previous faults, the airbag which in the absence of any detailed info I will leave well alone, and the fuel level sensor issue which I intend to investigate further tomorrow. I chickened out on pulling out the ecu at the moment as it appears to be a lot of hassle and if it is not necessary will be a lot of time wasted. However it's very useful to know where it is and the access procedure in the event that it is necessary to go in.

Regarding the fuel level sensor/gauge this issue occurred in the last ten days,intermittently upon turning the key to ignition position the gauge stays at empty and the low fuel light stays on, it is possible to start the engine, if it is then turned off and restarted the gauge will sometimes operate normally indicating true fuel level although it can go to fault condition in driving.

One other item that I have experienced a problem with is the coolant temp, gauge indicating a low reading, I have checked hose and rad temp. using a I/R thermometer, indicates 68c after a journey of approx 25 miles. I have today fitted a replacement temp sensor as it is a quick job , however makes no difference. I have a replacement thermostat which I will fit another day as the job appears to be a pita for access.
I did notice today that the main rad cooling fan appears to run when the climatronic front interior fan is selected on and goes off when the climatronic fan is turned off, noticed this at tickover shortly after starting engine, is this normal?, seems a bit odd to me. These are the only other problems electrical or otherwise that I have experienced.

I apologise for the length of this post and thanks once again for your advice.


Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: Chrispb on April 06, 2015, 01:09:09 AM
Was there any evidence  of bad solder joints on the relay.

Is the door led working as it should

Is the airbag warning light on all the time ignition is on

Fuel gauge may be faulty connector on tank  faulty tank unit or worst case instrument cluster

you should be able to test clocks for full sweep using vcds iirc output tests

The cooling fans running with the climatronic on is correct, so a good chance your aircon is working?

Sounds like the engine is running quite cool, probably thermostat and yes not very easy on a mk 1

And lastly heated rear window now working ok?
Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: starg8 on April 06, 2015, 07:34:15 PM
Hi Chris

109 Relay - nothing instantly visible on this, just reworked all solder joints plus cleaned switching contacts.

Door led - functions as it should

Airbag - no warning light on when ignition is on, although I am guessing here that if the resistance value of the igniter increases or becomes a permanent condition then the airbag light will stay on.

Fuel gauge problem appears to have ceased for now, had a look around the fuel tank but no wires or connector visible, can it be accessed through the floor from inside the car, (previously had a golf where this was the case).

All gauges show fsd upon testing.

The hrw is not operational, when the switch is pressed a relay in the fusebox clicks but does not latch, also the pilot lamp in the switch only lights whilst the switch button is held in.I wanted to check the switch so I have tried to remove the centre console facia after taking out the screws located behind the climatronic and below the bottom open shelf but It gives the feeling that it will snap upon attempting removal. Are there any other fixings that I should be removing. I have checked the wiring on the tail gate, found that the wiring gaiter has at sometime been discarded, no signs of surgery on the wiring so I guess it perished and was removed, the vacant holes have been filled with a piece of flexible electrical conduit and silicone,

Apart from that the car drives ok now ( for the time being)


Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: Chrispb on April 06, 2015, 10:24:34 PM
Does the airbag light come on briefly when ignition is switched on similar to the ABS light.

Trap in floor under middle row of seats.

The heated rear window switch does not stay in normally when switched on, the HRW relay is part of the GEM board, if your sure the tailgate wiring is OK the problem may lay with the relay or dodgy soldering of the relay to the board.
Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: starg8 on April 08, 2015, 09:20:23 AM
Hi Chris

Not even a glimmer from the airbag light when ignition is first turned on,

Still working on the hrw issue, there is a definite short to earth on the positive switched feed to the hrw, cable colour is black on tailgate harness but does not appear to be a black cable of that size on any of the plug in connectors on the GEM, awaiting arrival of a wiring diagram before I proceed further or I might pull all the connectors and use an insulation resistance tester to identify it at the connectors.

I do need to replace the hrw switch as the indicator lamp does not function, how do I access/remove the switch.

Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: Chrispb on April 08, 2015, 12:45:28 PM
Hi Merv

According to the diagram the colours change inside the tailgate
Title: Re: location of ecu (engine) on Mk1 sharan tdi
Post by: starg8 on April 08, 2015, 04:32:51 PM
 Many thanks for the wiring diags. and info re the console, after disconnecting the relevant plug on the GEM the white cable on pin 8 passed insulation test, no fault to earth/ continuity ok, If there had been a fault on this side of the circuit the fuse would have blown.

After more testing with VCDS I found that the fault occurs momentarily at the point the orange indicator lamp goes out upon releasing the hrw switch. After passing this point to the switch rest position (button fully out) no fault detected. I have tried another hrw switch which was with the car when I purchased it, results identical.

The existence of the second switch suggests that the previous owner had problems in this area but conveniently never mentioned it.

As the hrw circuit is actually operational without any issues  other than the above I will run the car as is for now to establish that the hrw issue has no effect on daily use of the car.

Many thanks for your advice, much appreciated.