Relay 109

Hello community,
I know this topic can already be found in a variety of ways using the search function. Therefore, I had already done some reading on the subject last night.
Okay, now for my problem: my car has been stopping more and more frequently since yesterday. The engine suddenly cuts out, and after about 2 minutes, it can be restarted, but the glow plug indicator doesn't light up beforehand. This happened once last week as well, where the car briefly stalled while driving, but didn't turn off completely. Later, I experienced the problem I described above. Of course, there were no error codes stored. So far, so good, and according to some technical articles, the relay mentioned is a possible cause. I also bought the necessary part today from the dealer, and sure enough, the car is running smoothly again without any hiccups.
Okay, here's the translation:

'But now, to my question: the technical article states that this relay may become unusually hot. Where is the line between 'unusually hot' and a normal temperature? Is it even acceptable for the relay to get warm? When you touch the relay's casing while driving or after driving, it is noticeably warm.' The car now has 125,000 kilometers on the odometer.
Thank you for your help and the answers!
Regards,
Marcus.

Hi Marcus,

If you have the opportunity to have someone drive you to a dealer to get a new 109, try gently opening the 109 using a tool like a knife or screwdriver.
If you see cold solder joints, then you know what's wrong. Just reflow the solder and it should be fine.

Best regards, Rainer.

Hello Rainer,

Thank you for the super-fast response. To put it simply: a new relay should not get warm at all, right? If that's the case, I will exchange the item again on Monday and hope that will resolve the issue.

Regards,
Marcus.

Marcus_Nbg. wrote:

In plain language, that means: a new relay should not get warm at all, right?

Incorrect.
In a coil with a resistance of approximately 70 ohms (if I recall correctly), a completely normal power loss of almost 3 watts occurs at a voltage of 14 volts.
The relay becomes noticeably warmer than its surroundings after just a few minutes.

If it gets almost too hot to touch, there's a resistance issue in the load circuit -> needs to be repaired or replaced.

@ Ulf
It's not that hot. It's noticeably warmer than the rest, but you can touch it without getting burned!
I'm just going to wait and see what happens. If the philosopher's stone ever materializes, I will, of course, share the results!

Regards,
Marcus.

Hi,

Since the 109 model isn't that expensive, it's possible that you'll end up getting frustrated and kicking things if you're stranded in the middle of nowhere at 1 a.m. and the car won't start again after just 2 minutes.

I certainly had a lot of fun waiting for the tow truck for 2 hours in -15°C temperatures.

Best regards, Rainer.

@Rainer
Sure, I understand that there are more pleasant experiences than the one you described! So, that means you've always had a spare 109-series tire in the vehicle since then?
I installed the new one yesterday. I'm going to take a look at the old one and, if it's still worth it, have it repaired by soldering. Then at least I have a spare part for emergencies.

Regards,
Marcus.

I also replaced the 109 yesterday. It costs 11.60 euros. You almost start to wonder if it's even worth plugging in the soldering iron...

What color was the old one (black?) and what color is the new one (white?)
There are at least 5 "109" models in stock (black casing). The replacement models are all white. None of the white models have failed yet. The black models started experiencing problems with cracked solder joints after 1 to 2 years. The solder joint lasted for a maximum of 1 year.
The problem is that the hole for the solder pin is too large (leading to fatigue failure due to vibration and temperature/expansion). Apparently, this problem no longer exists at the Weißen Gehäuse location.

PS: There are still some "friends" out there who are unaware of the 109 issue.

Quote:

Have you always had a spare 109 [item] in the vehicle since then?

No, a working, built-in .

Hello everyone,

The new 109 is gray, while the old 109 was black.
'With the new one, there are no more problems; the car is running smoothly again. I opened the old one, and sure enough, I could see the problem described by 'Taxiratte' at two soldering points. However, it seems to be from the first production run, as the production date is 18/96.' Cost: €12.50 at the friendly store.

Regards,
Marcus.

'I also replaced the old black relay 109 yesterday (after it started malfunctioning). It was also black, and the solder around the pin was completely broken off. The old one worked fine for over 170,000 km (7 years) without any problems, but it started acting up just yesterday.' According to all the forum discussions, the new gray version (now produced in Portugal) seems to be the permanent solution to the problem.

Could you please tell me exactly where the 109 relay is located?

I probably have a faulty part in the car...


Best regards,
Michael.

In the fuse/relay box, there is a marking that says 109 (or 601 ).

Dear fellow sufferers,

I also have a Caddy cargo van here for my internship, model year 2001, engine code AYQ!

The other day, I was working on a slightly elevated section of a road, and right at the steepest part of the access road: the engine stalled in third gear!

Restarting it didn't help either; I had to have it towed. An hour later, it started up again, seemingly by chance!

It didn't matter to me that the preheating indicator didn't light up when I turned the ignition on; it was mysterious. I was then told that the car had apparently caused similar issues with drivers before, but that nothing had been found so far.

Okay, I checked the system with the diagnosis tool, but of course, nothing was found. I read in the forum that relay 109 is the first suspect!

I then removed the cover for the relay, etc. I opened the fuse box and tapped on relay 109 – it appeared to be related to the intermittent failure of the glow plug light. Sometimes it wouldn't come on, but tapping the relay would make it work again...

I removed the relay, opened it up, but there are no obvious defects visible in the solder joints. It's the version with the milky-white casing!

If the relay is functioning correctly, the car runs perfectly fine - with absolutely no issues!

We still have another Caddy of the same model, I'll try swapping the relay - the question is, when will the problem occur again? :/

Are there any other ways to definitively determine if the relay is faulty or to rule out other causes (e.g., broken cable, loose connector, faulty MSG,...)?

Thank you very much!

Best regards, Alex.

Hello Dr. Zaziki!

I wouldn't hesitate; I'd replace the relay in the Caddy right away.
The costs for this are likely to remain manageable and are certainly a better investment than spending hours troubleshooting and/or dealing with repeated failures, breakdowns, etc.
I would only start with the rather complex troubleshooting process if the problem persists.

Best regards from Munich!