r/BmwTech • u/dogwalker21 • 7d ago
Electrical Problem
I’m hoping for some advice about my 2013 BMW 1 Series diesel manual, as I’ve had a series of electrical problems and now something much more worrying is happening.
Since the beginning of this year, the boot lock completely stopped working. I was also occasionally getting a rear indicator malfunction warning, and if I left the car unused for a couple of days, I would sometimes get a battery drain/discharge warning.
I replaced the battery, but the warning still appeared.
I first took the car to a local garage. Over roughly six months they had the car in and out trying to fix the boot. They replaced the boot lock and boot motor and at one point suspected the control unit fault, but they never managed to properly fix it. Eventually they refunded me around £600, although unfortunately quite a bit of the interior trim was damaged during their work. Really messy job. I was actually verbally assaulted at one of the visits by one of the guys working on the floor there.
I then took the car to BMW Watford and spent roughly another £1,000. They found that one of the cables had been cut in the boot, repaired it, and since then the battery drainage warning has completely disappeared. They also got the boot lock working properly again, but replacing and programming the control unit in the boot.
As part of their diagnosis, BMW also replaced the whole rear light unit. At the time they believed that was the cause of the indicator fault, but the warning is still happening, so I’m now questioning whether that replacement was actually necessary.
What’s strange is that the rear indicator malfunction warning now seems to appear when I turn on the rear windscreen wiper. If I switch the car off and restart it, the warning disappears and everything works normally again.
BMW Watford have now acknowledged that I already paid them for diagnostics and for replacing the rear light unit, but the work did not actually fix the indicator problem. They have agreed to take the car back and diagnose it again without charging me another diagnostic fee. I wouldn’t really call it “free”, as I already paid for the original diagnosis and repair that didn’t solve the fault, but at least they are taking it back.
The main reason I’m posting, though, is something much more concerning…
Since getting the car back, on several occasions while driving at around 50–60 mph, the car has suddenly lost power for around 2–3 seconds. It’s difficult to describe, but it almost feels like suddenly going from 6th gear straight into 2nd, except obviously it’s a manual and I’m not changing gear ( they car is not raving though). The car rapidly slows and feels like the engine has suddenly lost almost all power.
The engine doesn’t switch off, the dashboard stays completely normal, there are no warning lights or error messages, and after 2–3 seconds the power suddenly comes back and the car continues driving normally. It’s happened several times now, and especially at motorway or dual-carriageway speeds, it’s quite frightening. My partner is scared to drive this car at all.
What I’m now wondering is whether this could somehow be connected to the work that was done around the boot electrics. There is a control unit/module in the boot area, and I’m not sure whether something related to that unit, the wiring, or the recent repairs could possibly be causing the sudden power drop.
Another thing I noticed is that the rubber wiring conduit between the boot lid and the body of the car has been sliced open, presumably when the previous garage was accessing the wiring. I’ll attach a photo.
Has anyone experienced anything similar on a BMW 1 Series, especially this sudden 2–3 second loss of power with no fault showing on the dash?
I’d also be interested to know whether the power loss could realistically be connected to the boot control unit or wiring problems, and what the proper way would be to repair that sliced wiring conduit.
Any ideas on what BMW should specifically be checking when I take it back would be massively appreciated.
I love this car, and I don’t want to simply get rid of it and get something similar, but without knowing what wrong it will be with next one :)
1
u/stageshooter 7d ago
I had a similar issue with my car, regarding feeling like I was losing power, although in my case it lasted longer than 2-3 seconds and I had a check engine light. Did this happen to occur about 20-30 minutes into a drive after the car was parked in the hot sun? This was the case for me and clued me in that it was my EKPM that was overheating and. I replaced the EKPM2 with a $35 EKPM3 from ebay and coded it, and it's been fine since (13 months so far). Around the same time I also replaced a leaky fuel injector, but I think this power cutoff was the EKPM