"Electric Parking Brake Malfunction" "Vi$it your dea£er"

2016 RX350 rear brake squealerstarted sounding.
Installed new rear brake pads.

Could not push the brake caliper pistons in because thelectric parking brake motors had moved out compensating for the thinning brake pads.
Removed each motor and screwed its “pawl” in.
Pushed the hydraulic brake pistons all the way in and slipped the calipers over the new brake pads.

Brakes work fine but now the parking brake, which we do not use, will not operate. (Also Cruise Control does not operate.)


Thank you.

Since I am not familiar with the electric parking brakes, I would take it to someone who is.

I have electric parking brakes. Although I’ve never worked on any, I did read somewhere that before you replace pads you’re supposed to put the car in service mode and retract the e brakes electronically. Then do an e brake reset when you’re done. This is forum information only so I’ve never verified it.


Are the parking brakes part of the rear brakes on this vehicle? That’s different then what Toyota/Lexus has designed in the past 20+ years. The parking brakes on ever Toyota/Lexus we’ve own since 2005 are shoe brakes built inside the rear rotor. The rear rotor is also a drum. Pads on the outside for rear brakes, and then small shoes inside the rotor/drum.


Thank you.
I do not khow to place in Service Mode. Nor how to retracthe brakes electronically.
(Assume thathe brakes push out until certain level of resistance is detected through the motors. That way they keep compensating for the brake pad wear.)
Shall try disconnecting the battery and reconnecting after 10 minutes.

Yes. Thelectric brake motorscrew-tighten a threaded shaft againsthe inside of the caliper brake piston causing both brake pads to clamp down onto the brake disk - just as the brake fluidoes.

When released, each motor reverses and its threaded shaft retracts to presumably the previous position.

Things could well be different with your Lexus, but I can tell you the Subaru tool kit includes a special tool for manually retracting the electronic e-brake if it freezes in the “on” position. Have you checked to see if Lexus provides something of this nature?

Once that tool is used, one must have the system serviced–preferably at a dealership. Luckily, this system has never malfunctioned in the 11+ years that I have been driving it, but I’m prepared to use that tool to manually release the e-brake, if necessary.

Edited to add:
Subaru extended warranty coverage to 15 years/unlimited mileage on their 2010-2014 vehicles equipped with an electronic e-brake. Have you checked to see if Lexus might have provided similar extended warranty coverage?

I use a scan tool to retract the parking brake. After completing the brake repair, the indicator light is flashing. To initialize the parking brake, lift and hold the parking brake switch for ten seconds.


“Drum-in-hat” rotors are mostly gone now. Instead of 2 separate systems, the rear brakes and parking brake have been integrated into one simple system. Rear service brakes operate conventionally and the parking brake is operated by electric motors that push the piston to engage. Fewer moving parts to wear/seize.

@Robert-Gift just didn’t use the proper procedure to replace the rear brakes.

1 Like

OP, is there a reason you don’t seem to be using a repair manual procedure that applies to your specific make/model/year when you work on your car’s brakes? Or is the problem that the procedure doesn’t explain how to deal with the parking brake?

Access to Toyota repair manuals cost;

$20 for two days

$90 per month

$480 per year.

I miss the days when you could buy a printed factory service manual, and use it as many times as you want, for as long as you own a compatible car. Paying for a time-limited “subscription”, which often uses technological measures to make it very difficult to print anything is just not something I’m willing to do.


Repair manual? We don’ need no stinkin’ repair manual.

Have been replacing brake padsincearly teens.
Did not realize that I would create a problem by screwing the threaded shafts IN to allow the pistons to clear thew brake pads.

Assumed the motors would operate and screw the electric parking brake threaded shafts OUTo where the resistance would indicate the new pads were againsthe brake disks.
Then back awayvhen the parking brake was disengaged.
But NOOOOOOooooooooo.

The hydraulic brakes are fine. Fortunate thathelectric parking brake is off.
It will not operate but we do not use it. (A switch controls whether it engages in PARK or not.)

Have you applied and released the parking brake using the switch?

But that paper manual is obsolete the day after you use it. It will not provide updated repair info, part supercessions, revised service procedures, software updates, etc. You get the picture.

Your local garage has (or should have) subscriptions to at least 2 of these types of service information providers. They have to spend all that money they make on something.


Thank you.
Know nothing abouthat. But I caused the “malfunction”. Would a warranty cover that?

Thelectric motors have two internal hexagonal screws which I removed with an Allen wrench.
Then the threaded bolt which pushes the piston head out to apply the brake pads is visible.
The bolt has an internahole in which I.nserted a flathead screwdriver to turn the bolt. The motor has a shaft which inserts into that hole to turn the threaded bolt.

Good idea!
Nothing happens when turning the switch on to apply the parking brake.
Nothing happens when turning the other switch on which automatically applies the parking brake when the vehicle is placed in PARK.

True, but on the other hand, for the price of the 2 day subscription you can download the entire manual. That’s really not a bad deal at all.

$20 for 2 days of access sounds better than fixing the electronic parking brake

Any time I see something I’m not sure about, I inform myself BEFORE tackling the job

That might mean the factory service manual, identifix, the factory technical website, maybe even a video, etc.

Better to get an idea of how the system works and what the repair entails before possibly damaging something


ESPECIALLY when it’s the brakes.