Electronic Parking Brake not working - 2015 Spark EV

[SmokeyPete]

Hello Guys,

I recently failed my state safety inspection on my 2015 Spark EV due to the Electric Parking Brake doing nothing in hold the car in place.

When I activate the parking brake I certainly can hear a motor noise. At first, I did not think I could investigate any further without obtaining an absurdly short T-25 Torx key/bit to remove what looks like two bolts that secure the vibration dampener. I am relieved to find that I was able to simply use a 13mm wrench on the top and 14mm on the bottom caliper bolts and the dampener stays attached to the bolt when removed.

I noticed that when I remove some of the plastic inside the wheel-wells and look upwards towards the trunk I see an electric actuator. Is this the one and only actuator?

So I could examine the brake shoe hardware and springs I placed a 2x6 piece of wood inside the calipers so I don't get squirted with Brake Fluid again when the piston accidentally pops out due to being forced to press the foot brake before activating the parking brake.

I removed the rotor and see the disc-drum (Aka Top-Hat) setup. When I activate the parking brake lever I see zero movement inside.

Has anyone any experience with this Delco 13501701 Parking Brake Module? It seems odd that it would be broken if it makes noise but then again ,maybe it never really worked 100% right to begin with. I hate to buy the part just to find it was something else.

 

[NORTON]

I would figure out how the brake pull cables are attached at the actuator and see it the cables are rusted up and causing the problem.

Good luck. Keep us informed!

Some libraries have access to mitchell manuals and you can print off the whole E brake section to take home.

It is a safety system and you should get it working.
You can pull up on that switch while moving and it should act like a hand brake.

 

[Kermit]

When we had to pass inspection in our old car we had to hit the parking brake and then hit the accelerator. When you hit the accelerator in the Spark EV the parking brake automatically releases. I guess I'm just curious of how they are testing that this keeps the car from rolling?

 

[SmokeyPete]

The guy at the inspection station told me the parking brake did not work. I asked him how one could ever determine that the car was not holding at 1300RPM when it was electric in the 1st place. He then said it does not even hold at all!

He then put the car in neutral, applied the parking brake and placed his foot outside the door and pushed it 2-3 feet.

That shut me up good.

Massachusetts 540 CMR 4

Brakes. (Non Commercial Vehicles)
(a) The inspector shall operate the vehicle to test the parking and service brake. The
parking brake on all vehicles will be tested by accelerating the motor to approximately 1,200
to 1,300 RPMs with the vehicle in the lowest forward gear against the brake in the applied
position. The vehicle will be rejected if the parking brake will not hold. The service brakes
will be tested at a speed of between four and eight MPH. Service brakes must be reasonably
equalized so that the vehicle does not pull to either side when applied. A test with the brake
meter shall be made at a speed of 15 to 25 MPH in all questionable cases.
(b) Brakes shall be adequate to stop the vehicle from a speed of 20 MPH in not more than
the following distances:
Service (foot) Brake Pleasure Vehicles 30 feet
Trucks and Buses 40 feet
Parking (hand) Brake All Vehicles 80 feet

 

[SmokeyPete]

Hey guys,

I ended up pulling the rear cover that covers the underbelly where the exhaust would normally be on an ICE Spark.
I found that the electronic actuator had somehow become disconnected from the right brakes themselves. I don't know how this could have happened or how I got through the last two inspections with the parking park in such a state but it is what is is.

I referenced by friends AllData to inch the brake cables closer and closer using the non-scantool method until I was able to hook things back together: (See Below)

----------------------------------------------------------

Electronic Parking Brake Cable Tensioning

With Scan Tool - Preferred Method

Block the drive wheels.
Install a scan tool to the vehicle.
Place the power button in Service Only Mode.
Select Configuration/Reset Functions from the electronic parking brake control module menu.
Perform the Parking Brake Calibration procedure.
Without Scan Tool - Optional Method

Block the drive wheels.
Place the power button in Service Only Mode.
Apply the brake pedal.
Place the transmission in PARK.
Momentarily lift then release the EPB switch to apply the EPB.
Momentarily press down then release the EPB switch to release the EPB.
Repeat step 5 and 6 to cycle the EPB on then off an additional 4 times.
The EPB module will be calibrated and proper tension will be applied to the parking brake cables.

 

[NORTON]

Smokey,
Thanks so much for this useful info!

 

[an7mal]

from https://www.brakeandfrontend.com/gm-electronic-parking-brake-procedures/ (website has a nice picture). Looking for the EPB module fuse. The only fuse I could find a reference for was the Electronic Brake Control Module Fuse, 41 in the engine compartment.

GM Electronic Parking Brake Procedures
The parking brake control module has an internal motor, apply actuator, release actuator and temperature sensor.

By
Andrew Markel
on
Jan 18, 2021
When replacing the rear rotors or pads on GM models with an electronic parking brake, it might be necessary to disengage the parking brake during the job. The preferred method is with a scan tool. But, it can be performed using the following procedure:
Block the drive wheels.
Turn the ignition switch to the ON/RUN position with the engine off.
Place the automatic transmission in PARK or manual transmission in NEUTRAL, as equipped.
Apply and hold the brake pedal. The brake pedal must remain applied throughout the parking brake cable tension release process.
Press and hold down the electronic park brake (EPB) switch for approximately 5 seconds.
Observe the PARK BRAKE lamp on the instrument cluster.
When the PARK BRAKE lamp flashes, release, then immediately press and release the EPB switch. The parking brake cable tension is fully released.
Release the brake pedal.
Parking Brake
Most 2014 and newer GM vehicles are optioned with either a manual or electric parking brake that utilizes a drum-in-hat arrangement. To adjust the manual system, lock the pedal in the full-release position and adjust the cable using the correct procedure listed in the service information. In some cases, the shoes will need to be adjusted to fit the rotor.

Vehicles with an electronic parking brake have a switch in the center console, which takes the place of the manual parking brake system (the foot pedal and release handle). In case of insufficient electrical power, the electronic parking brake can be neither applied nor released.
The parking brake control module has an internal motor, apply actuator, release actuator and temperature sensor. The parking brake control module also contains the logic for applying and releasing the parking brake when commanded by the EPB control switch. When the parking brake control module receives a signal from the switch, the internal circuit board temperature is checked to verify it is within operating range before the control module performs the requested operation.
The EPB module receives hard-wired signals from the apply/release switch. The module receives wheel speed sensor signals, engine torque, gear information, and brake pedal signals through the GM-LAN. The system can be calibrated using a factory or enhanced scan tool. If you do not have a scan tool, you can use the following procedure to adjust the module:
With the ignition ON, apply and hold the brake pedal.
Push and hold the EPB switch down for 5-6 seconds.
Release the EPB switch.
Momentarily push the EPB switch down.
Remove the EPB MODULE fuse and reinstall.
Apply the EPB.
Release the EPB.

 

[Flyrye]

Great stuff. Quick question. Other than not having it useable anymore, and other issues with leaving the parking brake fully released?

Recently did a rear disc brake replacement because I live in the rust belt and only recently learned the trick of occasionally braking in neutral to exercise the hydraulic brakes.

Hence mine rusted and seized up. I didn't do anything with the parking brake and now the drum part of the rotor/drum keeps getting hot.

 

[Flyrye]

None of that worked. And the fact that only the right side is hot and not the left? Could it be a wheel bearing? My mechanic friend says you don't always hear the hum

 

[SmokeyPete]

I do like to drive on the highway and when I see myself going downhill I put the car in NEUTRAL and then brake or shift into DRIVE at the last 200-500 feet for the battery savings/disc rust removal.

Obviously this is the dangerous hyper-miling behavior similar to that of what I used to do with my Jetta TDI Cup 6-Speed Manual (why I'm called SmokeyPete), but does this also possibly damage my transmission/electronics/motor etc?

 

[Infinion]

I do like to drive on the highway and when I see myself going downhill I put the car in NEUTRAL and then brake or shift into DRIVE at the last 200-500 feet for the battery savings/disc rust removal.

Obviously this is the dangerous hyper-miling behavior similar to that of what I used to do with my Jetta TDI Cup 6-Speed Manual (why I'm called SmokeyPete), but does this also possibly damage my transmission/electronics/motor etc?

Could use a dedicated thread about this.

Neutral will cut power to the auxiliary fluid pump located next to the 1ET35 coaxial gearbox and inside the drive unit [1] [2]. The case holds 4.2L of Dexron III transmission fluid and the aux fluid pump circulates it around the planetary and differential gear sets.

If you're coasting in neutral for brief moments, the wear from loss of power to the circulating pump will be minimal, but if you do something like coast down a big hill or tow the spark flat many miles at high speed, it will cause uneven wear. The faster the speed of the car in neutral, the more centripedal forces will flick off residual oil coating the parts. Some gears might dip into the case oil, while others remain dry.

The best way to coast while minimizing transmission wear, which is especially relevant at high speed, is to stay in DRIVE or L, have your dash display the drive power in kW, and feather the accelerator pedal, gently adjusting your foot pressure until the regen/drive power is around 0 kW. The software will keep the motor in a freewheeling zone without generating or motoring.

Same driveline configuration with the Bolt but different gear design:

The spark has a smaller and more compact 3.16 :1 (2015) and 3.87:1 (2014) final gear reduction driveline compared to the bolt's 7:1, so it can use the planetary gears in links 1 and 2 above instead of the large ring gears the bolt needs for its reduction.