2017 CX-5 Electronic parking brake malfunction

[alexjagal]

Hello experts,
I recently replaced my rear brake pads. while doing so I accidentally damaged the EPB actuator and replaced it with new one.
Now the EPB only engages on one side and not the other side. Also the warning is "Electronics parking brake malfunction" and I am so confused as why on Earth would this happen just after replacing the brake pads. I am not even able to get it out of the service mode. Any idea.

 

[edmaz]

... the warning is "Electronics parking brake malfunction" and I am so confused as why on Earth would this happen just after replacing the brake pads. ...

Well, based on your own words, you did quite a bit more than just replace the pads

The actual physical position of the actuator (i.e. the percentage of 'winding') must exactly match the last position that the EPB controller previously saved. There's no self-correction built in, if there's a mismatch between those two.

So you'll have to try getting them to match by manually turning the actuator to be fully opened up, while the dash is showing that maintenance mode is active. You might want to look at a picture of a new actuator, in order to see what the 'home' position looks like.

Also, the small tabs of the caliper piston need to be oriented exactly N/S, so turn the piston a slight bit if necessary to get that positioning. Then reattach the actuator, and hope you got it right. If not, retry after doing a very small actuator winding adjustment, until it works. Good luck with it!

 

[alexjagal]

Thank you; based on the workshop manual it does mention that the controller will learn the new position of the EPB motor. As in my case it should.
I also made sure that the Piston position is oriented exactly N/S.

ELECTRIC PARKING BRAKE CONTROL MODULE REMOVAL/INSTALLATION

What I have tried so far is
a. Swap the Actuator motor Left & Right.
b. Replaced both the Left & Right calipers.
c. Tested with new EPB control module.

My diagnostic tool shows error codes C2005:13 and C112A:77.

 

[edmaz]

Thank you; based on the workshop manual it does mention that the controller will learn the new position of the EPB motor. As in my case it should.
I also made sure that the Piston position is oriented exactly N/S.

ELECTRIC PARKING BRAKE CONTROL MODULE REMOVAL/INSTALLATION

What I have tried so far is
a. Swap the Actuator motor Left & Right.
b. Replaced both the Left & Right calipers.
c. Tested with new EPB control module.

My diagnostic tool shows error codes C2005:13 and C112A:77.

I have no idea under what conditions and circumstances the controller will learn the new position of the EPB motor. But I can say for certain that there have been MANY posts similar to yours on various sites, where failure to do maintenance mode correctly resulted in a persistent EPB issue that would not go away on its own.

And the description of that C112A:77 code is: 'Incorrect electric parking brake motor gear unit position". So it seems apparent that this controller is not very good at 'learning'. The only other thing I can think of, aside from continuing to try reassembling the EPB actuator, is the bleeding of the ABS. Although I've never had to do it myself, I believe a scan tool is required to successfully bleed ABS, if any air gets in.

Now that said, I can't imagine why air in the ABS would produce that motor gear position error code, and I'm not saying that bleeding ABS is likely to fix your issue. Perhaps if you retry the EPB actuator reinstall, and check the codes each time, maybe something will change and give you more information about what the root cause is. I hope you're able to get this sorted out!

 

[alexjagal]

Well, your suggestion of "The actual physical position of the actuator (i.e. the percentage of 'winding') must exactly match the last position that the EPB controller previously saved." seems to be correct. I was curious to know why it might have happened and repaired the old actuator and connected and there you go. All the error codes disappeared because the old Actuator position matches the EPB Controller configuration. This confirms that the EPB Module is still functional, and I still need to replace the actuator with a new one. Thank you very much for the suggestion.

Just FYI, This is what the repair manual suggests.

If the electric parking brake control module is replaced, perform the automatic configuration and related parts check using the following procedure.

(1) Switch the ignition ON (engine off or on) and wait for 30 s or more.(2) Switch the ignition off and wait for 3 s or more.(3) Switch the ignition ON (engine off or on) to allow the electric parking brake control module automatic configuration to be completed.(4) Using the M-MDS, perform a DTC inspection and verify that DTCs U2300:55/U2300:56 are not displayed. (See DTC INSPECTION [ELECTRIC PARKING BRAKE].)
• If DTCs U2300:55/U2300:56 are displayed, go to the DTC troubleshooting procedure. (See DTC TABLE [ELECTRIC PARKING BRAKE].)
(5) Operate the electric parking brake and perform the related parts check.(6) Release the electric parking brake.(7) Verify that the brake system warning light and the electric parking brake warning light turn off.
• If the brake system warning light and the electric parking brake warning light do not turn off, perform a DTC inspection because an electric parking brake malfunction may have occurred. (See DTC INSPECTION [ELECTRIC PARKING BRAKE].)
(8) Operate the electric parking brake again.(9) Verify that the brake system warning light turns on and the electric parking brake warning light turns off.
• If the brake system warning light does not turn on or flashes, or the electric parking brake warning light does not turn off, perform a DTC inspection because an electric parking brake malfunction may have occurred. (See DTC INSPECTION [ELECTRIC PARKING BRAKE].)

 

[edmaz]

Well, hats off to you for hanging in there on this, and getting the problem resolved! Based on reading and participating in a great many DIY efforts such as this over the years, I'd say that 99% would have given up somewhere along the path you traveled to get this done and taken it to a shop instead. Well done indeed

 

[alexjagal]

Ok, Now I finally replaced the broken EPB Motor with the Genuine Mazda parts and the brake light starts flashing and the EPB does not function, any idea?

 

[edmaz]

So you're not quite finished with this just yet. Some of the just don't want to give it up. Are the codes the same as the ones you posted previously? Did you put the damaged factory part and the replacement side by side, to confirm they're an exact match, including the amount each one is turned?

 

[alexjagal]

Thank you for the response edmaz. Yup the code was same. I figured it out that the connector was bad. After replacing the connector the new EPB Motor start working. So for this whole time the connector that connects to the motor was the culprit. Lesson learned. I am all done. Thank you.

 

[stickerbush]

Congrats for sticking with it and fixing your obscure problem! Good work.

 

[edmaz]

Nice detective work to get this finally buttoned up and in the rear view mirror

 

[Matt M]

Hi there i just saw that you had the same issue as i do have now.

While changing the rear brake pads I put the car into brake service mode, after changing the brake pads on the left wheel, in the garage wasnt enough space so i had to turn the car the other way, for the right wheel i forgot to put the car in maintance mode so the pistone got all the way out, I ordered new caliper with actuator, I changed it and when i turn the parking brake on, the brake warning light is on on the dashboard and on the obd shows the code " right actuator mechanical failure".

Could you please let me know how did you resolve the problem on your car?

How did you find out that the conector was the problem, and where did you buy the new conector from?

 

[alexjagal]

Hi there i just saw that you had the same issue as i do have now.

While changing the rear brake pads I put the car into brake service mode, after changing the brake pads on the left wheel, in the garage wasnt enough space so i had to turn the car the other way, for the right wheel i forgot to put the car in maintance mode so the pistone got all the way out, I ordered new caliper with actuator, I changed it and when i turn the parking brake on, the brake warning light is on on the dashboard and on the obd shows the code " right actuator mechanical failure".

Could you please let me know how did you resolve the problem on your car?

How did you find out that the conector was the problem, and where did you buy the new conector from?

I understand the hassle as I myself went through this, if you already replaced the the caliper set than it all should be good.
The way i found out was by swapping the actuator left to right, than i knew that whatever i do only one side is engaged so i tested with multimeter and figured it out. I did not have to replace the connector because the pin was bent while i removed the old one so, I straightened the pin with pliers to make sure it has a good contact with the actuator.