Electronic Engine Management Light

[MCFabia]

Hello All,

Could anyone assist please?  I have a 2002 Skoda Fabia 1.4 Classic 8 valve,.  The electronic engine management light (orange engine shape) is permanently lit and the car is running in limp mode particularly from start and low engine revs.   Having reached 45 mph it runs clear and smooth.

 

Originally diagnosed by the garage as a sensor, now diagnosed this morning by a main Skoda dealer as faulty wiring in the engine bay wiring loom.

 

Is this common?  Does anyone have any constructive advice before I spend circa £400 on  a replacement engine bay wiring loom?

 

Would appreciate any information which may help.

 

Thank you.

[Breezy_Pete]

If I were you I'd be spending some time having a damn good look around the wiring in the engine bay to see if I could find the damaged part(s). May be a straightforward cut/splice repair.

(For Skoda to have stated that a new loom will fix it, suggests to me that they have found damage.  They may/may not be willing to share the location with you, dunno? Nothing to lose by asking). 

 

Seems very unlikely to me that an entire new engine loom is necessary.  If Skoda won't give you any clues, check bits that go near hot/very hot bits first.

[MCFabia]

Thank you for your assistance.  Skoda main dealer advised  that the plug for the cam shaft sensor is damaged.  They removed the plug and found shielding wire to be damaged and wiring having been previously twisted together with tape.     This I guess is the reason they are suggesting a new engine bay loom.

 

Any further thoughts?

 

Thank you

[Breezy_Pete]

I wouldn't mind betting that Skoda/VAG sell a repair connector for this, with wire tails already installed. Make a nice job of soldering and heatshrinking that in place and you're >£380 up I reckon.  If you don't have the gear to do this, befriend someone who does!

 

If you were nearer I'd do it for you. 

 

Can you post a photo of it as-is?

[DanSej6]

There's two looms in the engine bay. There is the main one that links into the dash area - these have been known to gather water near the ABS pump and cause all sorts of issues, normally CAN-BUS related ones though.

 

Sounds to me like its the other sub-loom that's been diagnosed (the main one is nearly £1000 from what I remember).

I'm not aware of any replacement loom for the engine speed sensor like there is for boost sensors on the diesels. The issue with the sheilding wire may be the reason why the sub-loom has been priced up.

Where as normal wiring is just taped up, the sheilded wires have a rubber outer coating that has a metal sleeving inside and a wire is attached to that and then linked to the ecu. I don't see how that could be retained or replicated with a wiring repair. I suppose the 2wires from the engine speed sensor (lets call it the crank sensor from now on) could be ran directly to the engine control unit and the sheilding bypassed, but it's surely there for a reason?

 

If you fancy a nosey around, the camshaft sensor is located just above the oil filter on the front of the block. The crankshaft sensor is up on the right hand side of the block, near the gearbox. The single wire plug to the lower right is the oil pressure switch.

Edited 30 September, 2013 by DanSej6

[Breezy_Pete]

...Where as normal wiring is just taped up, the sheilded wires have a rubber outer coating that has a metal sleeving inside and a wire is attached to that and then linked to the ecu. I don't see how that could be retained or replicated with a wiring repair...

 

Trim back another few millimetres of outer insulation, pigtail a bit of the screen braid, solder a wire to it.

 

Or if it's a foil screen with a drain (un-insulated) wire, trim back until you've got enough of the drain wire to solder to.

 

I just can't believe that a 5mm reduction in screen coverage will affect function.

[MCFabia]

Thank you both for your advice and guidance, this has been most helpful.

 

As neither myself nor my husband can solder to any standard one may deem as acceptable, I will now give some further thought to my next steps.

 

Having bonded with my Fabia which has still only done 18,000 miles from new, I intend to persevere until resolved!!   My husband remains puzzled at my preference for the Fabia as I walk passed the SLK!

 

Thank you again.

[Olly87]

Could you not get an auto electrians advice? As theyre usually mobile and would repair if viable. Only a thought to try save buying a new partial loom.

[MCFabia]

Hello All

To continue my saga and once again seek further advice and guidance.

 

The car remains running in limp mode with the engine management light illuminated on the dashboard.  This despite the Skoda main dealer having today removed and replaced the engine bay sub loom, at a cost of £395, this has however failed to correct the fault and we remain in limp mode.

 

They are now advising further exploration of an additional section of the engine bay wiring.  Should this not be found to be the cause of the fault they indicate that it could possibly be the ECU itself.

 

There is an obvious limit as to the value of continued expense in respect of this 12 year old car, albeit that I treasure it and I would welcome any further thoughts, views or pointers as to possible next steps.

 

Thank you.

[fabrel]

I don't think the mpi has a limp mode. Have you got the fault codes from the garage? Did the sensor get changed as the first garage pointed out? Did you not take it to an auto electrician? Does it rev freely but struggle once you drop the clutch? Does it idle normally? Fuel consumption changed?

[MCFabia]

Hello All

Really begining to struggle now, feel its difficult to justify the price of a new ECU, if that's what it turns out to be.

 

A used ECU with matching numbers appear to be available on the internet for circa £30.   

 

Would a used ECU require re programming to match my car?  If so, how would I best achieve this?  Are there any independent garages/engineers that anyone could suggest/recommend in my area Scunthorpe, North Lincolnshire, that would undertake this?

 

Having spoken to two auto electricians they appear not to have the relevant software, or maybe they don't want the job.

 

As there are many knowledgeable people on this forum/site, I am sure someone will hold the key to solving this issue!

 

Many thanks