VW Sharen 1.9tdi 2001 - engine management light

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Fri 24 Oct 2014 22:00
VW Sharen 1.9tdi 2001 - engine management light - sparky100

Hi, I wondered if anyone could shed any light on why the EML starts to flash sometimes while driving and goes out and may flash again 30 miles later for a few minutes and then go out. There doesn't seem to be any pattern to it. Could it be a sensor or maf unit playing up. Car drives as normal and starts well. Thank's for any info. Sparky100.

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Fri 24 Oct 2014 23:01
VW Sharen 1.9tdi 2001 - engine management light - 659FBE

The usual advice is to scan for fault codes, but as it's a PD I'll hazard a guess for you, based on the symptoms you describe.

VAG in their infinite technical wisdom potted the engine temperature transducers in hard epoxy. When heat cycled (remember where they live) the differential expansion within a rigid brass tube breaks the delicate thermistor elements and they fail intermittently open circuit.

The early transducers have a black body, the later (slightly improved) version is green. Good replacements are available cheaply from GSF. Remember to renew the "O" ring seal and buy a new plastic "horseshoe" retaining clip if you think you might lose or break the old one.

It's located at the transmission end of the of the cylinder head next to the tandem pump. Replenish any lost coolant with the correct G12 mixture and vent as required. It may take a few start cycles to extinguish the light - if this is the problem.

659.

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Fri 24 Oct 2014 23:36
VW Sharen 1.9tdi 2001 - engine management light - The-Mechanic

It won't be the coolant temp sensor at fault as when that faults the EML will stay on permanently and you'll have either poor starting when cold or poor running when hot.

My best guess is its the glow plug light that's flashing ( the coil shaped one, not the engine shaped one) yes ? If that's the case, check all the brake lights are working. The Sharan like other VW's have two brake switches, one for the lights, one for the ECU's EPC (electronic performance control). Both need to send the signal simultaneously and if one or the other is faulty you get the symptoms you describe.

If this is indeed the fault, get both switches changed and recheck the brake lights.

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Sat 25 Oct 2014 00:49
VW Sharen 1.9tdi 2001 - engine management light - 659FBE

The PD engine control software uses fuel temperature as a reversionary mode if the coolant temperature sender gives "implausible" (VAG terminology) information. The engine will start and run in this condition with barely noticeable degradation in performance.

I would however agree that if the glowplug lamp is flashing, a cause can be a fualty stoplamp switch. Accurate information is needed.

As always, diagnosis over the wires is not straightforward. The VAG diagnostic system is comprehensive and generally works well. However, for the price of a sender, if the original is black, I would change it as a first move - I've seen far too many faulty ones.

659.

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Sat 25 Oct 2014 21:55
VW Sharen 1.9tdi 2001 - engine management light - sparky100

Hi thank's for that. I have checked the brake lights and sometimes they work sometimes they don't. Could you tell me where the two switches are located, i have tried to have quick look behind the brake pedal but seems very congested and then run out of daylight. Will have a better look in the morning. Will the two switches be in the same place.thank's for any help. Sparky 100.

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Sat 25 Oct 2014 22:29
VW Sharen 1.9tdi 2001 - engine management light - elekie&a/c doctor
There is only one switch on these.It is located on a bracket just above the brake pedal metal arm.It can be a bit tricky to access as it mounted very close to the steering column.It will either be a 2 pin or 4 pin connector.
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Sun 26 Oct 2014 20:14
VW Sharen 1.9tdi 2001 - engine management light - sparky100

Hi, just managed to get brake switch off, not the easiers job for a simple operation. Took switch to bits and found burnt contact. Filed contact and cleaned, reassembled and put back. Seems to have done the trick so far. Thank's for your comments, saved me taking to have the codes read for something so simple. Sparky100.

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