Fabia 1.4 no spark

[Nick1664]

Hi All

 

I have a 2006 Fabia 1.4 petrol. Having been driving perfectly it suddenly stopped and has not run since. We have looked at the codes which suggest crankshaft sensor and ignition secondary circuit. We have changed the crankshaft sensor but its made no difference there is still no spark.

 

We checked the connections to the crank sensor and one of them shows 5v when the ignition is switched on

 

Any ideas fellas?

[Tech1e]

You should have 5v in, an earth and then a pulse signal out on the other wire. An LED test light should pick it up if it's working, obv test whilst connected.

Does the rev counter move when cranking?

[Nick1664]

Cheers for that

 

The rev counter doesn't move when cranking

[Tech1e]

Then the ECU isn't getting a crank signal.

[itavaltalainen]

Suggests that sensor itself has gone or the wiring to the sensor. Don't have a wiring diagram for Skodas but you should be able to find out which is GND, you seem to know which is 5V and the third will be the signal. Using an LED with appropriate resistor in line you can do an easy check to see if it's the sensor itself or the wiring.

 

Also does VCDS spit out any errors?

[Nick1664]

Thanks guys

 

sorry to be really thick but how to I use an led to test this. I know which is +5 and can find which is gnd. I know how to make an led light with resistor but i'm afraid im from the era of minis and rwd escorts. Also not sure what a VCDS is

 

Oh dear sorry guys

[Tech1e]

You need an LED test light. One that uses and LED rather than a bulb.

[Torbo]

Why not try another coil pack? Get a cheap used one. Good to have anyway. I have a pack under the driver seat... Paid about 50 pound..

Edited 29 May, 2016 by Torbo

[Tech1e]

If there is no crank signal a coil pack will make no difference.

[SuperbTWM]

What sort of sensor did you buy, its not beyond the realms of possibility that the new sensor is faulty, if you follow Techie's advice it will confirm this

Edited 29 May, 2016 by SuperbTWM

[TMB]

Is it the 16 valve or 8 valve?

[sepulchrave]

Thanks guys

 

sorry to be really thick but how to I use an led to test this. I know which is +5 and can find which is gnd. I know how to make an led light with resistor but i'm afraid im from the era of minis and rwd escorts. Also not sure what a VCDS is

 

Oh dear sorry guys

 

You can test the output from a hall effect device (crank sensor) using the AC volts setting on a multimeter, you should get ~0.5V AC between signal and ground while cranking the engine. Make sure the new sensor is mounted flush and you haven't left it proud at all otherwise it won't pick up the signal from the crank, the tip of the sensor should almost be touching the trigger wheel.

[Torbo]

If there is no crank signal a coil pack will make no difference.

 

Does he have a crank-signal?

[Tech1e]

Does he have a crank-signal?

No, the rev counter isn't moving.

[Torbo]

No, the rev counter isn't moving.

Then I understand!

[Nick1664]

Thanks everyone

 

will have another try this morning

[Nick1664]

Hi all

 

The saga continues........

 

We have rerplaced the crank sensor again and we now get a signal and the rev counter moves when cranking but it still wont start. We have re-read the codes and are now getting a P0353 code which is the coil pack on no.3 cylinder. Replaced the coil pack still nothing.

 

No. 3 coil pack has 2 brown wires which appear to be earths a thin purple wire and a thicker purple and Black wire. I only have a multimeter and on cranking the 2 purple wires do nothing on AC setting and show a small fluctuating voltage on DC

 

Lost me im afraid

[Tech1e]

A coil pack down won't stop it running, it would just misfire.

P0353 is an electrical fault on the coil. Assuming the plug is ok and swapping the coil pack to another cylinder does nothing then there is a chance whatever wiring fault you have is also effecting the other coils. Looking at the crank sensor issue and how that is resolved now I am wondering if that has been cured by the sensor of my moving wiring in that area. Be a good place to start looking.