Slightly unrelated, there’s also a good amount of effort for car manufacturers to make it much more complicated and expensive to keep your old car running, so either you pay a fortune keeping it running, or it’s planned obsoletion to get you to buy something new…
With that, I have a funny story to share regarding BMW’s. My E70 X5 is 11 years old and has 76k miles on it, and was kept in immaculate condition. The N55 engine is pretty rock solid, unlike the N54…But it’s everything around it with electronics usually ends up being problematic.
My car, like every other modern BMW, has an electric water pump that usually goes out around 75kmiles. Mechanically it’s fine, but it’s all the electronic encoders that the car’s ECU computer talks to to precisely control the water pump fails first.
Replacing the water pump, t stat, belts, and belt rollers wasnt terribly difficult. It was about 1 day’s job total for a garage mechanic. But when I fired the car back up, I had a check engine light up, and my OBD scanner lit up like a christmas tree with a bunch of errors about an electrical short.
BMW stealership knee jerk reaction was that “with such an old car”, the engine wiring harness needed to be replaced and rewired.. $1500-2000…. Oh hell no…
So I spent a few days (weeks) troubleshooting and found this very interesting thing. I blew a black box called the “integrated supply module” found in the engine bay…
This black box BMW says is a very intelligent one time use fuse that protects critical electronics in the engine from electrical shorts. If it detects there’s an electrical short in the engine electronics, it will blow and prevent catastrophic damage to the electronics in the engine…..
Well, for $200 MSRP, this one time use black box clearly must be really really sophisticated in the way it protects vital engine electronics and the ECU. I mean, my BMW already has 2 fuse panels that take standard fuses, and BMW chose to include this separate intelligent single use “integrated supply module” to protect engine electronics… So this $200 one time use black box clearly must be doing something special that regular fuses in a fuse panel cant do, right?
Well, I decided to cut mine open…
[img_assist|nid=27762|title=ism2|desc=|link=node|align=left|width=400|height=300]
I replaced this one from a box of 20 fuses I bought from Autozone for $4.99, and even that was expensive compared to Amazon…
[img_assist|nid=27765|title=ism5|desc=|link=node|align=left|width=400|height=300]
Really, BMW? Instead of putting these 7 fuses into the fuse panel that already exists in this car, you decided to put these in a sealed 1 time use black box that costs $200 to replace….Fvck you.
Oh, and back to the $1500-2000 engine harness rewiring that the stealership insisted I needed to for a car “this old”…(lol)….After a week’s of diagnosis, I found the short was most likely caused by a rodent or squirrel chewing these 2 wires…
….Which brings me to one of my previous points. If a modern car has an electrical problem, most of the authorized service centers don’t actually take the time to diagnose what the real problem is. They just recommend a complete replacement (part swapping)…which costs considerably more, and may/may not actually solve the original problem…
And part of the reason for this is the techs at these service centers probably aren’t trained that well to really diagnose electronic problems or be able to really do anything with them…
And, at least for BMWs, the electrical wiring in the engine bay isn’t really that well protected from the elements/weather/etc for this to last troublefree for many years. What you see in the pictures above are actual can bus wires that the engine’s ECU uses to communicate with critical engine components, and all these wires are in are plastic wire looms that aren’t really sealed from the environment and that also begin to crack and break over time…..So these aren’t built to last for 20-30 years…
Fortunately for me, troubleshooting and fixing shit like this is a hobby for me. Otherwise, after a week’s worth of troubleshooting, I was ready to kick my car off a cliff and get something else.
