Car Info: Mazda CX5 2015 Sport

Note: This issue is still being diagnosed, so some of the information provided may not be applicable or accurate. Please read at your own risk.

Description of failure: The 7.5A SRS1 fuse in engine compartment position 42 continues blowing for no apparent reason. See link_1 for the actual location. This fuse keeps blowing, crippling the electric power steering. All dashboard lights, including the check engine light, come on when this fuse blows.

Causes of the problem: Because the condition is intermittent, its cause is unknown. We know the fuse blows after a few hours of the car being off. Once, while driving, a fuse blew, posing a major safety risk. It seems that as soon as the start button is pressed, the fuse blows. The problem started unexpectedly, the fuse blew after 2.5 hours parked, and the fuse broke when trying to start the automobile.

What has been done so far:

1. Following the electrical diagram, my mechanic has located the subsystems attached to the SRS1 fuse.
   1. Airbag systems
      
   2. electronic power steering
      
   3. ABS Module
      
2. Full reset of all computer codes after the failure first appears. This "fix" provided a few hours without the fuse blowing up.
   
3. Verify no burn cables under the dashboard. All good there.
   
4. Took the card to the dealer initially and after replacing the SRS1 fuse they declared the issue as fixed. Fuse blew the next day.
   

Next steps for troubleshooting the issue:

1. Disable the power steering motor and see if the fuse continues to blow. If not, the power steering motor/module could be the cause.
   
2. Disable the ABS module and see if the fuse continues to blow. If not, the ABS module could be the cause.
   

Link_1: https://fuse-box.info/mazda/mazda-cx-5-2013-2016-fuses
Link_2: https://cardiagn.com/mazda-cx5-2018-...ematic-4-of-4/

To the Mazda Forum community:

Does anyone have a similar problem with their Mazda CX5? If not, does anyone have any suggestions? Also, does anyone has a copy of the Mazda CX5 2015 Electrical Diagram? All I would find was one for a 2018 CX5 (see link_2).

Thank you in advance,

 

I found this information on an older model CX-5

This is the second occurrence of the same issue, but while driving the vehicle at highway speeds, all dash lights illuminated (check engine, turn signals, temp warnings, etc) simultaneously and the information screen displayed an alert "engine inspection required". the incident also resulted in a loss of power steering/heavier-than-normal steering effort and brake warning indications, on the first instance (July 10, 2014), Mazda roadside assistance was contacted, and the vehicle was towed to the dealer with no fault/cause found. On the second instance (July 15, 2014), the vehicle was driven directly to the dealership. Technicians were able to diagnose the issue to a loose ground connection in the passenger front fender well.

 

Hmm funny seeing this after a interesting thread and my response sabout the cables. LOL

Nice find as always Lobstah

You can see the small gauge OEM ground cable. And the large gauge additional ground cable I installed and routed directly to the engine head.



The oem cable is attached to the top of the strut tower on a small tab. They barley kept the paint off the area of the cable contact. And that's it for the ground on many new MAZDAs








The blue cable is one of 2 that I added of which one goes from the engine to directly attaching it to the alternator and the other chassis ground to engine mount. That would be the solid part of the mount not insulated by rubber.

 

I don't tax the power on my 4-wheel vehicles at all, so I rarely have the need to upgrade anything but the battery.
The cheap *** "miniature" stock batteries they come with now just plain suck.
But when I had my motorcycles, especially the sport touring ones, I always upgraded the battery and cables and occasionally the alternators.
Though my BMW sport tourers were all pretty beefy in that department.
It was a PITA upgrading in motorcycles but when you're running heated gear, radar detectors, GPS, phones, cameras you'll be stranded in a hurry if you don't.
The same would apply to one's car/suv/truck if additional electronics were added, like a 200w power amp and a keg cooler for instance

 

We took a trip to Texas 2 weeks. I failed to connect my battery tender when I returned the battery voltage was down enough that I charged it before attempting to start it to reduce the battery damage. So I was well aware of the electronics that can slowly use up battery power when a Mazda is not started over short periods of time.
I would think in Maine during both winter and summer months you would value the peace of mind of having better cables? LOL I guess the first time the ole Mazda leave you calling AAA... hahahahaha

On many of my bikes I went the other direction. Smaller lighter batteries or battery eliminators.

 

There are many types of bad/loose grounds.
While it is true that a loose ground in itself will not cause a fuse to blow should that loose/bad ground come in contact with something charged it usually will.

My thought is the issue he's having is a bad wire and/or fuse/fuse box connection as it continues to happen after the vehicle is shut-off.
I've also seen rodents work evil magic on vehicles causing all kinds of bizarre electrical issues.

 

Very true very true. I'm hoping for the original posters sake that your example or somebody else hopefully can chime in that has the exact same problem. Fortunately and unfortunately for the original poster Mazdas have pretty decent wiring. Sure ain't no Dodge that's for sure. Those vehicles are nightmares. Especially with the grounds!

 

That would be ALL Chryslers products.
And don't forget the old Rambler products with the 6-volt systems.
On second thought, I'd like to forget that...

 

Generally this is correct but remember......
A bad ground is a little different than a lose ground. An electrical motor will surge power demand during starting if the ground is not making good contact and intermittently grounds during that start phase the fuse protecting the circuit will blow. The Some Mazda models ELECTRIC ASSIST POWER STEERING MOTORs

 

Hello Everyone, here is an update:

My MAZDA CX5 2015 is not longer blowing the SRS fuse. The car was at the mechanic shop for a few weeks trying to find the problem. My mechanic provided a list of items he worked on in order to get the short to go away. In my opinion we (mechanic and I) are not entirely sure of the root cause for the problem but here is the troubleshooting process that went on for the record. The list below comes from the invoice my mechanic provided.

NOTE: My mechanic did an outstanding job and I cannot believe all he went thru to get this car going.

• Remarks and Labor Description

1. 7.5 APM fuse that controls electric steering and SRS systems has a short
2. Diagnose electrical problem
3. Problem with the car includes time to road test, hook up test equipment and trace the problem to its cause
4. Trace short to SRS control module under the center console
5. Remove and installed: SRS control module (U) 14127836
6. Short in connector from fluid (my mechanic thinks there was a drink or something like that spilled on the center console that prompted the short)
7. Clean both connector and cover to protect from fluid from cup holder. (my mechanic cut a small plastic bottle and encapsulated the connectors in question to avoid liquids going into them in case of an accident)
8. Short in front crash sensor (right front). (after replacing the SRS module apparently there was a shorted crashed sensor as well. Apparently the car had been an in accident prior to me purchasing it used)
9. Remove front bumper cover and lights assy, missing bolts to headlights housing found bad ground (paint covered)
10. Remove tape from right front crash sensor ground, remove paint ground mounting points and retest
11. Short cleared at this time. Reinstall 7.5 AMP fuse and retest 3 days. Ok. (my mechanic had to take a segmented approach to troubleshooting the problem since the car seem to fail every time it had been idle overnight)
12. Installed missing bolts and clips.
13. Check tire pressure and set to manufacturer specs

Total cost for the repair including labor, testing and a "new" SRS module from eBay was $773,88.

As you can see by the notes my mechanic did not provide an specific root cause for the problem. It could had been the drink that was spilled on the center console, the SRS module, the crash sensor, the bad ground he found or all of the above. However, I wanted to documents this for the forum since the car seems to be working now. I will try to update some time in the future to let you all know if the car is still working ok.

Thank you all for your advice and kind help,

- Suutuko