Mazda 6 Forums banner
1 - 20 of 26 Posts

· Registered
Joined
·
10 Posts
Discussion Starter · #1 ·
Hello guys. Long story, short story.

Having electronics issues with my Mazda 6 2010 2.2 diesel manual.

Everything started with small issues like doors wont lock/unlock with remote, but like next day it works again. It was random time by time.

Then problems started to get more serious, like i wasnt able to start the car, everything lights up, but no cranking when i turn the key, like completely dead (but i hear that diesel pump works and some clicking under hood) but again same day after 2 hours, everything works just fine.

Week later after work, same problem, cant start car, left it overnight, came back, started the car, but all dash lights came up, went home, couple hours - lights off, only engine check was lighting, next day, its gone.

So everything seems fine again, but after some time, i was home, it was late night, and neighbor calls me and say i left lights on, i come to the car and seems i cant turn them off. So i start the car, left it running for some time, and was able to turn it off, that happened couple of times.

And now at the final, my gauge lamps not working, fogs lamps not working front and rear, rear lamps not working (only the braking ones lights up when i push the brake) license plate lights also not working. Inside spedometer lightning also dead. When i inster the key, arrows on spedometer lights up, but when i start the car, its off.

So i checked bulbs are just fine, all fuses fine, i clean all the grounding wires, checked everything with multimeter, battery is perfect, relays are perfect so i pretty much investigated lot of stuff.

So final i went down to BCM (body control module) and found this:

Table Wood Plant Rectangle Tableware

Material property Rectangle Wood Tree Plant

Finger Thumb Nail Wood Wrist


It wasnt wet when i took it out, but these connections doesnt look good, so my question, should i try to replace BCM or it just needs proper cleaning or its to late to clean and i should not waste my time? Cause the connections inside has the same corosion.

If i replace BCM will it be enough or the wirings needs to be replaced also?
If this needs cleaning, what tools should i use, to enter inside these plastic connections and what to clean with.

P.S i clean little what i was able to reach, so when i put it back, my front headlights used to work on "auto" and now it doesnt.

So for me feels like its good news cause something "happened"

Sorry for my English, im not a writer, hard to put all minds in correct order, hope its readable and waiting for any tips/ideas to solve this.

P.S i pretty much read every single post on whole internet about this electronic problem with Mazda, so there is like no situation, which have been solved, a lot of similar stories and that even the mechanics scratching their heads. So dont want to spend thousands in service for nothing. Cause i did so much by myself and learnt a lot of things also, so would be nice to make the job done!
 

· Administrator
Joined
·
18,860 Posts
Welcome to the forum!

Don't appoligze for your english, it's perfectly readible. Heck, you speak better than a lot of native English speakers :D

Ouch, that's quite the crazy problem, but glad you found your likely source.

Personally, I'd stay far away from that BCM and get a new one. Electrical gremlins can be a complete pain in the arse to pinpoint and there's no telling what else has been messed up on that board due to the corrosion.
 

· Registered
Joined
·
10 Posts
Discussion Starter · #3 ·
Welcome to the forum!

Don't appoligze for your english, it's perfectly readible. Heck, you speak better than a lot of native English speakers :D

Ouch, that's quite the crazy problem, but glad you found your likely source.

Personally, I'd stay far away from that BCM and get a new one. Electrical gremlins can be a complete pain in the arse to pinpoint and there's no telling what else has been messed up on that board due to the corrosion.

Thank you for your reply, glad to hear, thank you for positivity!

I dont know much about how this corosion can affect the part, just hoping for the best. Maybe its not receiving correct information, blocking or something, thats why im trying to get correct information. Must be someone who has knowledge about it, hehe.
 

· Registered
Joined
·
7,852 Posts
Electrical gremlins can be a complete pain in the arse to pinpoint and there's no telling what else has been messed up on that board due to the corrosion.
Especially since you didnt show the PCB.
 

· Registered
Joined
·
7,852 Posts
That tells me that the problem might be in the wiring then as i dont see any ruined traces. I would carefully open the harness and see if you can carefully peel back some insulation on a couple of the wires that match corrosion in the plug socket, and see if its leeched up the wiring or not. Id go at least an inch or two, cause if its farther up than that, youre hosed on replacing it.
 

· Registered
Joined
·
10 Posts
Discussion Starter · #7 ·
That tells me that the problem might be in the wiring then as i dont see any ruined traces. I would carefully open the harness and see if you can carefully peel back some insulation on a couple of the wires that match corrosion in the plug socket, and see if its leeched up the wiring or not. Id go at least an inch or two, cause if its farther up than that, youre hosed on replacing it.
Thanks, will check, but im still looking for the answer if this corosion issue could cause all the electric wierd stuff happening in my car? I mean what are the chances.
 

· Registered
Joined
·
10 Posts
Discussion Starter · #9 ·
chances are pretty good.
Where is that thing located and is there a water issue in that spot?
Vehicle Car Gear shift Motor vehicle White


Here. And these all connections is close to this plastic, and others deeper is perfectly fine as you can see in the pictures above. I dont see any water leak, it is always dry here. Car was on the hard rain all the night, i checked after its no signs of water, i was driving through water on thr street, also nothing.

One thing, i was worrying is grounding above the front driver side wheel, under air box i will add picture, surface is little rusty, but i have cleaned the exact place where it is connecting, can it be that rusty surface around somehow affects grounding wire?

Tire Automotive tire Hood Motor vehicle Tread

Automotive tire Motor vehicle Bumper Automotive exterior Wood
 

· Registered
Joined
·
10 Posts
Discussion Starter · #11 ·
just saying that by appearance, there is something that caused the corrosion. Like @TalonTsi90 said, it might have leeched up the wires, but what got in the wires to corrode them to begin with?
It could be that it got some water, but i mean i live in north Sweden, here is like 6 months winter, so it could be of bad isolation, sometimes during winters my windshield gets frozen from inside. All i know its not a winter car, it likes summer, but it also starts in -33 with maybe couple starter spins, knowing its diesel. But ok back to the problem.

I want to know, how this corossion is affecting my car, wires, devices, the last i want to know, how it got here.
 

· Registered
Joined
·
10 Posts
Discussion Starter · #12 ·
Sorry for double posting, but there is one more thing, from the engjne fuse box, there is one plug with a lot of wires forgot how its called adding a pictures how it looks like, and is it the same wiring which goes to BCM block?
Trunk Electrical wiring Bag Automotive lighting Eyewear
Hand Guitar accessory Finger Motor vehicle Nail

Tire Automotive tire Hood Font Machine
 

· Registered
Joined
·
7,852 Posts
just saying that by appearance, there is something that caused the corrosion. Like @TalonTsi90 said, it might have leeched up the wires, but what got in the wires to corrode them to begin with?
Water can leak down the harness and get into the plug and then work back up inside the insulation.
 

· Registered
2005 6s Grand Touring Wagon
Joined
·
280 Posts
It could be that it got some water, but i mean i live in north Sweden, here is like 6 months winter, so it could be of bad isolation, sometimes during winters my windshield gets frozen from inside. All i know its not a winter car, it likes summer, but it also starts in -33 with maybe couple starter spins, knowing its diesel. But ok back to the problem.

I want to know, how this corossion is affecting my car, wires, devices, the last i want to know, how it got here.
From the looks of your connectors, the corrosion is probably shorting pins in the BCM, causing odd behaviour.
First step is to try to clean it all out. Try contact cleaner spray or white vinegar to start. Second step is a new BCM if the first step doesn't produce the required result.

The connector in your engine is typically coated in dialectric grease so should be fine. I can't tell you what the wiring is on that as I don't have the wiring chart for the car.
 

· Registered
Joined
·
10 Posts
Discussion Starter · #16 ·
From the looks of your connectors, the corrosion is probably shorting pins in the BCM, causing odd behaviour.
First step is to try to clean it all out. Try contact cleaner spray or white vinegar to start. Second step is a new BCM if the first step doesn't produce the required result.

The connector in your engine is typically coated in dialectric grease so should be fine. I can't tell you what the wiring is on that as I don't have the wiring chart for the car.
Yes i will clean it for sure, can i use this nail polish remover? Im pretty sure its safe to use? And i still would like to hear if this type of corosion can destroy the connected device or is just blocking the circuit.
 

· Registered
2005 6s Grand Touring Wagon
Joined
·
280 Posts
Yes i will clean it for sure, can i use this nail polish remover? Im pretty sure its safe to use? And i still would like to hear if this type of corosion can destroy the connected device or is just blocking the circuit.
What would destroy the connected device is if voltage goes in where it shouldn't. I don't know how sensitive that device is to this condition, so can't say for sure, but if there is 12V where it should be 0 or similar, it might take out a component. I'm guessing the BCM is pretty robust, but who knows?
 
1 - 20 of 26 Posts
Top