Felicia 1.9 D blinking glowplug light finally solved

[MikeFCriss]

Hello fellow briskodians

My first car is a 1.9 D 2000 vintage Felly and it has a problem, or should i say it HAD a problem.

 

So let me describe.

I had a problem where upon ignition,when the engine is cold and when it's warm outside, the glowplug light lights up for a second or so and then starts flashing, the engine will turn on but only after a second or so of cranking and the glowplug light flashes until the ECU drops the idle RPM, but when it's cold outside i need to crank a bit more 4-5 seconds.

Now when the engine is cold  that problem goes away and the glowplug light (as well as glowplugs) turns on solid and turn off as usual, which pointed to the infamous felly hotstart problem, but it isn't because if i immediately shut the engine off and then try to turn it back on again, no go ,same problem.

Same goes if the engine warms up after a bit of running.

I searched the internet far and wide and i never found anybody with the same, or similar problem.

 

And so My troubleshooting adventure begins

I checked the temp sensors resistances and according to the fellys official service manuals it's ok.

Then i checked the glowplugs themselves and measured both individual resistances as well as bulk current draw and ,

again compared to the service manuals they were fine.

The glowplug relay was ruled out based on the fact that when engine is cold glowplugs turn on.

So the only component left was the ECU for which i do not have excess money to spend on so i just got used to the problem. 

Then I (driven by the lack of money) tested the output from the ECU to the GP. relay and while testing that AHA , boom , There is yu'r problem !!! the glowplugs turned on as i put some sideways pressure on the relay itself.

At first i thought that relay plug contacts were bent and dirty but it turns out that the relay is faulty. I opened the relay and there is a small pcb inside mounted to the side, connecting the coil itself to the contacts to the bottom and a bleeder resistor across the coil, and there it was ,the cause of my agony, a bad solder joint on the on the coil , more precisely a cold solder joint, so when it is cold inside engine compartment the joint shrinks and it makes contact so the glowplugs turn on but as the ECU keeps the coil energised or 10 or so seconds the coil heats up (or when the engine compartment warms up) and the joint expands thus breaking contact and , sad day , NO GLOWPLUGS for me !!!

 

Key is turned - ECU tries to energise the relay - bad relay - no glowplugs -no current draw sensed by ECU - ECU confused - ECU flashes the glowplug light until it switches to the next routine.

 

Needles to say that a simple resoldering of the mentioned solder joint solved the problem :-) 

And the best part is that It was free!!!

 

Now the relay itself is not that expensive so i would probably buy it if i only knew that it was the cause of the problem, but the intermittent fault led me to the wrong conclusion. 

 

Afterall there is a moral of the story, that i should of gone by because it's the second commandment of electronics: "Never , and I mean NEVER assume anything when troubleshooting something. Murphy will get you"

I am interested , does anyone else have this problem.

BTW Sorry for the long post but i just wanted to share my experience as detailed as possible with You because i couldn't find any similar problem on the interwebs.

 

Cheers from the Knight in the white felly.

[RicardoM]

Congratulations for the persistence in solving the problem yourself and also for repairing the relay yourself   instead of buying a new one. Moreover, it is always a good thing  :clap: to share in detail the issues with your car and how you ended up solving it.

 

Now I will share some thoughts from my experience related to your problem.

 

Skoda Felicia is a reliable car. If an electrical fault occurs, it is most often due to corrosion and/or bad contacts. Always simple things. Never major faults, like the ECU. You need to do something really stupid to fry the computer. As I said, Felicia is a little tough car. As an aside note if the Czechs would have the liberty to build a new Felicia without VAG supervision, bye-bye VW Polo and Golf sales...

 

A VAG-COM scanner would have helped you a lot. The error 01050 (glow plug monitoring) would had been stored as a sporadic error. Read carefully chapter 01 (Self Diagnosis) from Diesel Injection & Glow Plug System in Skoda Felicia service manuals.