2013~2016 Dealer can't find problem in CX5 that blows fuses

I'll make this as short as possible, but I think the chain of events is important to figure out what to do:

1. Daughter leaves interior light on on 2015 CX5. Battery dies.
2. Tow truck driver apparently connects jumper cables wrong; then corrects himself and car starts.
3. All lights on dash illuminated. Power steering doesn't work. Car can be started, however.
4. Tows car to Trusted Mechanic who doesn't do electrical, so then car is towed to dealer.
5. Dealer replaces fuse**, charges her $180, and sends her on her way.
** There is some question as to whether this is a 7.5A fuse in fuse box or main fuse on battery.
6. Daughter drives car to East Jesus in Central Valley of CA and problem happens again but without jump start this time.
7. Has car towed back to dealer. Dealer spends a week but cannot find problem. Apparently replaces same 7.5A fuse.
8. Diagnosis: either the power steering, ABS, or SRS module needs to be replaced. Cannot determine which. Dealer says we'll put in a new SRS module ($1300) and see if that fixes it.

I now have the challenging decision of either allowing my daughter to drive a potentially dangerous car, or to blindly replace "modules" in the hope that it will solve the problem.

What do I do?

Thanks,

Chuck Hawley, new member and really in need of some good news.
 

madar

Contributor
:
2016.5 CX 5 Touring AWD, 2015 SCION XB
Does the dealer know about the tow truck driver's screw up? That kind of mistake can be harmful in so many ways...
 
:
Ottawa, Ontario
:
17 Mazda 6 GT
Make sure you document everything. Keep all receipts and a log of the activities you have had to endure.
This way when the vehicle is finally fixed, you can go after the tow truck driver/company for reimbursement.
No way should you be paying for his screw up.
Hooking up the cables backwards on today's vehicles, with all the electronics in there, is a sure fire way to fry something.
 

Ronzuki

South Central PA
:
2018 CX5 Touring
:
w/ Pref Pkg
Everything on that 7.5A circuit (or what ever it is, which is pretty important info to know in order to diag) is suspect at this point after the tow truck driver's screw-up. Since the PS didn't work initially after said screw-up as you say, and it's electric, I'd say that's a great place to start digging. Presumably the PS worked after mystery fuse was replaced the first time. It is now blown again, and presumably, the PS is no longer working, again? If not, the PS clearly was not happy about the reverse polarity condition. Doesn't mean anything else on that circuit, or the entire car for that matter, isn't subject to pre-mature failure. Reverse polarity protection is probably not something the nave automotive automation engineers have thought a need for...yet. that sort of 'feature' in controls and components costs more for certain. Dealer needs to know this occurred and you will likely need to fight the towing company to be reimbursed for the fix(es) which Mazda certainly won't cover when they learn the truth...which they'll need to know so they can fix the car.
 
Good idea re: documentation. Tow truck company owner is an a**hole, and was very rude to my daughter when she contacted him. Has TERRIBLE reviews on Yelp. Shoulda know better...

Chuck
 
There are about six 7.5A fuses, and one of them is identified as the SRS circuit. There is a 50A fuse for the ABS/Stability System. I can't find any fuse for power steering.

This appears to happen when the car is at rest.

I think the dealer, as well as Mazda US has given up, and is now in the mode of replacing expensive parts until the car stops failing...
 

madar

Contributor
:
2016.5 CX 5 Touring AWD, 2015 SCION XB
Good idea re: documentation. Tow truck company owner is an a**hole, and was very rude to my daughter when she contacted him. Has TERRIBLE reviews on Yelp. Shoulda know better...

Chuck
It wasn't AAA by any chance, was it?
 
I'd start by replacing all of the 7.5A fuses as well as the 50A fuse. The reverse poliarity may have fried something in more than one fuse, so the problem continues to exist as the chain remains broken despite the replacement of one fuse only. It's a cheap enough fix, and just may do the trick. If it doesn't, then you should try an experienced mechanic, other than the dealer ... replacing expensive modules blindly is no way to run a service department.
 
It wasn't AAA by any chance, was it?
No, as it turns out, it was the recommended tower for State Farm. Incidentally, we've had a series of not-our-fault accidents among my daughters, and State Farm has been A+ in taking care of the claims. I wouldn't normally call out an insurance company, but they have been fast and generous.
 
:
2010 Mazda 5 Sport
If the circuit is blowing fuses and all the devices attached to the circuit check out. Then it's the wiring harness. A wire got partially melted and is shorting.

Oh, and you need to dump this Mazda dealer. These guys are idiots.
 
Hi Friends,

Here's an update on the fuse-blowing CX5.

I took the car to my wonderful independent mechanic in Santa Cruz, Rusty. He narrowed the problem down to the SRS module, which was one of four modules connected to the SRS1 fuse. After replacing the module, the car ran perfectly for about 3 weeks and perhaps 1000 miles. However, yesterday, the fuse blew while my daughter was driving the car from Big Sur and sort of freaked her out. I think the PS, SRS, ABS and one other sub-system is on this fuse, or the power for those modules flows through SRS1.

I now have the option of asking Rusty to replace more modules, and I have NO idea if I can test the modules to see if one is the suspect. Any additional ideas?

Thanks for all of the helpful ideas.

Merry Christmas, Happy New Year!

Chuck
 

Avoidin Deer

Zoom Zoom, baby
Contributor
:
Central Virginia
:
2019 CX-5 Reserve
Take it back to Rusty. He found an issue that fixed it temporarily. Let him diagnose the problem further. Don't bounce around starting over with other mechanics. Heck, it could have been a defective SRS module...it happens.

I've had an electrical issue with my 2005 GMC Canyon (parasitic drain on the battery). Got it fixed, it was fine for 2 years, and the problem returned a couple of winters ago. Mine appeared to be the Body Control Module, but just like the SRS, it seems that lots of other stuff ties into it, so the causal issues can actually be further downstream. At least I can pull fuses when the thing sits to prevent the drain.

Good luck. Electrical system problems are frustrating enough on old school cars. These days you just can't self-diagnose.
 
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Ronzuki

South Central PA
:
2018 CX5 Touring
:
w/ Pref Pkg
Good luck. Electrical system problems are frustrating enough on old school cars. These days you just can't self-diagnose.
Hence the need for negotiating those 'waste of money' extended B2B warranties directly from the manufacturer. Everything in these damn cars are electrical. Low budget electrical...
Drop it off, get their loaner (and don't bother me until it's permanently fixed), pay the small deductible (if applicable), and go on your way...

Yeah, yeah...broken record....
 

Avoidin Deer

Zoom Zoom, baby
Contributor
:
Central Virginia
:
2019 CX-5 Reserve
Hence the need for negotiating those 'waste of money' extended B2B warranties directly from the manufacturer. Everything in these damn cars are electrical. Low budget electrical...
Drop it off, get their loaner (and don't bother me until it's permanently fixed), pay the small deductible (if applicable), and go on your way...

Yeah, yeah...broken record....
It's insurance. It all boils down to the odds, which are always stacked in the House's favor. If they weren't, the House wouldn't exist.

But I won't bash anyone for mitigating risk in their lives by using a 3rd party to aggregate resources in order to share that risk with each other. It's what makes 1st World economies hum...spending money to prevent/alleviate the bad things that happen in life. Heck, that's what my AAA membership is for.

Not many areas in life where one can buy peace of mind.

ps: Did we just Topic-Pivot?
 
4

40752

An intermittent short or high current draw on a circuit with multiple loads involved can be difficult to find.
Fuses blow for a reason. All the fuses were checked(in the whole car)? They check out OK?
I would start watching some Youtube videos, like this one:
In the video I’m surprised the mechanic didn’t address the problem of no voltage (therefore no battery connection) to the fuse block first.
 

Ronzuki

South Central PA
:
2018 CX5 Touring
:
w/ Pref Pkg
In the video I’m surprised the mechanic didn’t address the problem of no voltage (therefore no battery connection) to the fuse block first.
You shouldn't be surprised. The real problem here is a mechanic is... a mechanic. Being a mechanic doesn't mean you are capable, trained, experienced or qualified, to be an electrician, computer technician, IT pro, or software engineer. Again, I say the automotive industry has a very long way to go to learn the crucial lessons involved in what they are attempting to do with the modern-day automobile. They truly have 'leaped', in monumental fashion, before they 'looked'. Hence why the Mazda dealer/mechanic can not properly figure out why a fuse is repeatedly blowing. They do not have the proper people vetted, trained and employed to deal w/ what these vehicles have become.

My younger brother is an absolutely phenomenal mechanic. Meh-can-ic, period. My go to guy for assistance with anything in that realm. He absolutely blows at trouble-shooting anything electrical beyond a dead battery, blown fuse, or what a scanner directs him to specifically on a low-tech old-school automobile (lets define that as pre-2012 for the sake of argument here). Any deep electrical controls diag related to the level these cars are now requiring, he's lost as are the vast majority of 'mechanics'. Thus we arrive at the parts darts situation we are now seeing here in this thread, and we read about all to often, at great expense to you and me. Now days the dealers are referring to their mechanics as 'technicians', or techs. I chuckle at the implication everytime I here this now (by them merely stating it must make it fact) that these mostly mechanics are more qualified and capable ( watching YouTube videos doesn't qualify one to be competent at anything). Perfume on a pig. A Sanitation Engineer is still the dude slinging garbage.

The tow truck operator in this instance had taken a simple problem and rapidly elevated it to a legal level by shear stupidity.
 
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