Car won't start, key works? (BKD)

Hi everyone,

Amazing phenomenon: When I turn the ignition key back out, the engine keeps running. I had the key in my hand last and realized the car was still running. The only option seems to be to stall the engine, which I don't really like doing in the long run.

I have a feeling it might be related to the ignition switch, but I'm not entirely sure whether it's an electrical or mechanical issue. Does anyone have more experience with that?

VCDS log will be added later.

Best regards,
Yasin.

What vehicle, what year of manufacture?

Generally, a modern diesel engine with an engine control unit (ECU) requires a supply voltage to continue running, unless it is burning its own oil (e.g., due to turbocharger damage). Only older, purely mechanical diesel engines could continue running without voltage if the shut-off valve in the electronic stability program (ESP) was stuck.

That means the MSG (Main System Module) seems to be still receiving power. Whether it's due to a stuck relay or a faulty ignition switch, that needs to be investigated. However, disconnecting the battery won't change either of those issues. This means that even after disconnecting the battery, there should still be voltage at the MSG and a corresponding current flow, which should quickly drain the battery.

What about other consumer devices like the instrument cluster, etc.: Do they turn off after the key is removed?

I'm looking forward to the car scan.
Sure, here's the translation:

"Guste" is a German word that means "gust" or "gust of wind." It can also be used to describe a sudden burst of something, such as laughter or anger.

Oh, sorry - here are the details:
Golf 5
Manufactured in 2004.
Engine BKD.
Refurbishment to 30-byte Highline (but that was over 1.5 years ago).

When I remove the key, the combination instrument dims to approximately 50%.
The remaining power consumption continues even after the key is removed from the ignition (e.g., radio, subwoofer with remote control, ventilation).

When I bring the car to a stop (by shifting into 6th gear and releasing the clutch while braking), I experience the same phenomenon as when I normally park the car. Also, the "coming home" feature runs its timer and then turns off.

It has been like this for two days now - I think it's less likely that the battery is being drained (we hope so, at least ).

I'm also curious to see what the log reveals.

Hi,

A few weeks ago, I had a problem with my Seat: the relay 109 was stuck.
Very rarely did the engine stall, but later on, starting problems began to occur.
Tap the corresponding relay.

Best regards,
Adrian.

I would remove the casing, then disconnect the cable from the ignition switch and see what happens.

Okay, here are three log files (see description).

These were created as follows.
1) Read for the first time since the error occurred.
2) Errors cleared, engine started and stopped (yes, that worked), and then data was read.
3) Error code read after approximately 70 km of driving.

The errors for missing tail lights can be ignored (this is due to the conversion to 30-byte format).

After I cleared all the errors last night, I was able to start and turn off the car normally. This morning, I drove to work, and upon arrival, I saw the same error again - hence the third log file.

I'm curious to see what your opinions are.

EDIT:
@Adrian - Thanks for the tip, I can definitely see that, since almost all the errors are listed as "SPORADIC." A relay malfunction would explain that to me.

EDIT2:
To Adrian again: Relay 109 has already been replaced before (see /viewtopic.php?p=218380).
I could still try to force the old one back in.

jarobaldu wrote:

I had this problem a few weeks ago in my Seat: Relay 109 was stuck. Very rarely, the engine did not turn off.

I initially considered that as well, but if the 109 is connected, then the other appliances (lights, ventilation, etc.) should still turn off. However, that's not what's happening with this particular device. How was it for you?

A Golf V shouldn't have a 1.09-liter engine anymore, or am I mistaken?

Hi,

The Golf 5 still has that relay.
Unfortunately, I haven't had a chance to continue the analysis yet - I expect to do that on Sunday.

Currently, the "Exhaust System" warning light is still on (I think it's related to a malfunction in the intake manifold control valve).

My upcoming analysis steps:
- Check all fuses.
- Disconnect the battery for 30 minutes and then reconnect it.

Do you have any other ideas?

So... I've completed my initial analysis.
My idea: Throttle valve. I disconnected it, and the behavior is the same.

- All the fuses are okay.
- The battery was disconnected for 30 minutes, and the vehicle was started and stopped several times - without any issues. However, as soon as I drive a few kilometers, the problem reappears.

Regarding disconnecting the ignition switch:
- When exactly should I connect it? (With the engine running, or beforehand? --> Surely not beforehand, right? Keyword: immobilizer...)
- Where exactly should I connect it? As far as I can see, everything is connected to the steering column control unit.

Therefore, my next theory is:
Could it be that my steering column control unit is malfunctioning?
This is also a replacement part being used during the renovation work, specifically for the 30-byte Highline or multifunction steering wheel.

Quote:

So... I have completed my initial analysis.

You wouldn't have, otherwise you wouldn't have messed with the throttle valve.

The initial step would have been to read the posts here and try to understand them...

Please read the tips provided above again!

Best regards, Rainer.