Hi

 

Car is a 2008 Fabia II 1.4TDI (PD80)

 

I'm gonna start with the TL;DR.

Disconnected the battery for a longer time, maybe closer to an hour, to be able to clean a connector.

When i reconnected the battery i got a flashing Glow Plug light.

All fuses are intact.

All light bulbs are functioning.

Brake lights are functioning.

No fault codes from ECU when using ELM with Torque Pro app.

Emission DTC completes after a basic driving cycle.

All sensors i can see in the Torque app reads out normal.

Stereo and windows work just fine, stereo read "SAFE" for 5 secs on first startup.

Battery voltages 12.3v off and 14.4v on. Battery is 10 years old.

Engine is not in limp mode.

 

 

Now for the extra wall of text:

Car was in for a periodic check last week and only fault shop could find then was error on IAT-sensor(P0113), readings from that sensor was -40c.

Checked the IAT-sensor and it had around 2.5kohm resistance depending on temp around it.

Checked the wiring from the IAT-sensor and to the ECU and there was bad contact on pin 55 on the ECU connector itself.

Cleaned the contacts on the ECU with ISO and a plastic spatula, there was only visible corrosion on one of the pins.

Cleaned the connector to the ECU with ISO and a thin metal string.

Waited 30mins for the ISO to evaporate.

Applied vaseline to the mechanical parts of the ECU connector and the outside of the ECU connector to isolate moisture from entering the connector in the future.

Connected the ECU and then connected the battery, car runs better than it has done in years and now reads the IAT-sensor correctly.

 

Parts changed the last 5000km/2years:

Brake pads and disks.

EGR valve.

Timing belt, waterpump and associated parts.

IAT and boost sensor(combo unit G42).

The controller for the electrical windows.

Service parts like oil and filters.

 

 

Why is the Glow Plug light blinking and what can i do to fix it?

 

 

Sounds a bit sarky but, are the glow plugs ok?

1 hour ago, mrgf said:

Sounds a bit sarky but, are the glow plugs ok?

I would imagine that giving off some fault codes?

It starts as fast as i crank it and runs fine from the start.

Yeah, they are pre-heaters but I start straight up without checking they have gone out sometimes... Starts ok just might start easier, especially in the cold, if they have warmed up and the light has gone out! It just seems a basic thing to check. I have heard they are just a serviceable part, like tyres, brakes etc.

I cant figure out how to edit OP so il reply to myself.

 

Pulled the brake light switch out and it reports infinite resistance on pin 1 and 4 no mater what position of the switch. It also reports 0.07ohm on pin 2 and 3 no mater what position of the switch.

 

Now i need to find out where i can get a good new one quick, and can i drive the car without the switch there at all in the meantime?

@Truls84 - To get a new good brake light switch you need to buy from a VAG dealership.

 

As to driving the car without one, you do realise that this means having no brake lights?

I would not drive the car without the brake light switch fitted, just in case it is working okay some/most of the time, you will not have brake lights coming on when you brake.

 

Going back to what to what you have found buzzing out that removed brake light switch, that is exactly what you will find if you buzz it out while it is still in the "removed" configuration, it is only when you rotate it after fitting it that the switch can be buzzed out.

 

Edit:- KenONeill posted as I pressed submit, so, to add to or force the issue harder, buying from a VW Group dealership will mean that you will be buying the latest incarnation of that switch - and there have been a few over the years obviously revised/redesigned to try to make them work for longer.

Edited 4 May, 20188 yr by rum4mo

56 minutes ago, rum4mo said:

Going back to what to what you have found buzzing out that removed brake light switch, that is exactly what you will find if you buzz it out while it is still in the "removed" configuration, it is only when you rotate it after fitting it that the switch can be buzzed out.

Nice to know, I cleaned the switch with ISO and smashed it a few times, then I fitted it to measure it again. Now it works just as intended and the glow plug light disappeared.

 

1 hour ago, rum4mo said:

Edit:- KenONeill posted as I pressed submit, so, to add to or force the issue harder, buying from a VW Group dealership will mean that you will be buying the latest incarnation of that switch - and there have been a few over the years obviously revised/redesigned to try to make them work for longer.

Should i order a new one even tho i got the old one to work?

 

1 hour ago, KenONeill said:

As to driving the car without one, you do realise that this means having no brake lights?

I was to frustrated to think clearly, brake lights worked as soon as I installed the switch again.

Oh yes, time to get a new switch and maybe even a better one if your one is still the original as the design will have moved on.

 

So, if you get a new switch from any VW Group dealership, and it looks quite a bit different from the one that you have removed, the fitting procedure could be different from what is fitted at the moment. With original version and a few revisions, the switch was fitted with the brake pedal depressed out of the way, the later versions get fitted with the brake pedal in its normal "up" position.

 

Maybe you can work out why I know about these switches making no sense when removed from the car, the me the penny dropped when I checked a new switch against the old "all open circuit" switch, fitting something into the slot where the pedal metalwork is and compressing it allows you to rotate the switch to its normal "in position" configuration - then you can check the operation of the contacts.

So it seems to be the 'ol "broken" brake light switch scenario, Eh?  I thought you said the lights were coming on though? Perhaps an intermittent fault... The part is or should only be around £20 or so, buying a new one is most likely chapter than getting a used one from a scrapyard. Will last longer, too.

1 hour ago, mrgf said:

So it seems to be the 'ol "broken" brake light switch scenario, Eh?  I thought you said the lights were coming on though? Perhaps an intermittent fault... The part is or should only be around £20 or so, buying a new one is most likely chapter than getting a used one from a scrapyard. Will last longer, too.

The brake light DID work properly before i wrote the post, i checked them since i saw so many forum post about that switch. That was why i was baffled, no fault but stil blinking glow plug light.

 

2 hours ago, rum4mo said:

Maybe you can work out why I know about these switches making no sense when removed from the car, the me the penny dropped when I checked a new switch against the old "all open circuit" switch, fitting something into the slot where the pedal metalwork is and compressing it allows you to rotate the switch to its normal "in position" configuration - then you can check the operation of the contacts.

Not gonna check it again, but i know a brand new Audi A4 thats totalled just nearby, maybe i can snag the part from that car. The closest VAG dealership is a 2 hours drive.

You are having a laugh, I would not expect any newer VW Group cars to still have that design of brake light switch, things have moved on and cars get fitted with a Hall sensor in the master cylinder, a new correct brake light switch is the only way forward.