Why is macbook pro keyboard, mouse, and trackpad erratic after 10.9.3 update?

There are several possible causes for this issue. Please take each of the following steps that you haven't already tried until it's resolved. Some may not apply in your case.

1. Follow the instructions in this support article, and also this one, if applicable. A damaged or defective AC adapter could be the cause, even if it's the right kind.

2. Open the Bluetooth preference pane in System Preferences and delete all pointing devices other than the trackpad, if applicable. Disconnect any USB pointing devices. By a "pointing device," I mean a peripheral that moves the cursor, such as a trackpad, mouse, trackball, or graphics tablet. A plain keyboard is not a pointing device.

3. Start up in safe mode and test, preferably without launching any third-party applications. If you don't have the problem in safe mode, but it comes back when you restart as usual, stop here and post your results. Do the same if you can't start in safe mode. If there was no difference in safe mode, go on to the next step.

4. Reset the System Management Controller.

5. If you're using a Bluetooth trackpad, investigate potential sources of interference, including USB 3 devices.

6. A swollen battery in a portable computer can impinge on the trackpad from below and cause erratic behavior. If you have trouble clicking the trackpad, this is likely the reason. The battery must be replaced without delay.

7. Press down all four corners of the trackpad at once and release. If there's any effect, it's likely to be temporary, and the unit needs to be serviced or replaced.

8. There's a report that a (possibly defective) Thunderbolt Ethernet adapter can cause the built-in trackpad of a MacBook to behave erratically. If you're using such an adapter, disconnect it and test.

9. There's also a report of erratic cursor movements caused by an external display that was connected but not turned on.

10. If none of the above applies, or if you have another reason to think that your computer is being remotely controlled, remove it from the network by turning off Wi-Fi (or your Wi-Fi access point), disconnecting from a Bluetooth network link, and unplugging the Ethernet cable or USB modem, whichever is applicable. If the cursor movements stop at once, you should suspect an intrusion.

11. Make a "Genius" appointment at an Apple Store to have the machine and/or external trackpad tested.

It's not just the trackpad. As you can see by the original poster's subject line, the entire machine freezes sporadically. The trackpad and keyboard both are unresponsive.

For me, rebooting in safe mode fixed the problem, and then rebooting back to normal mode has, for a few minutes at least, eliminated the problem.

This is clearly a software issue with 10.9.3 that occurred after my recent upgrade from 10.6. Numerous people have reported this.

Clean the surface of the trackpad. Had this intermittent problem that tracking would stop. I used a window cleaner sprayed onto a sturdy tissue, not just a flimsey nose tissue, and wiped the pad well. It fixed the problem.

Not using any blue tooth but I notice that the track pad gest stuck.

Then the sensivity is raised so high that when you hover your thumbs over to do regular typing it over reacts.

It's just so painfully obnoxious and annoying.

Can't wait till the next Apple Computer gets killed by some other kids quantum computer they made in their back yard.

Yep Apple live by the sword so die by it.

I could send the laptop to get fixed but the problem is so random the tech might think he fixed it and then anytime the problem rises up again.

there was time when the man really cared and he was never called the man instead it was the dude. -inspired by the Big Lebowski :^)

Thank you, Kelly..it totally worked for me!

UPDATE:

After many experiments and many different BT headsets, and update to 10.9.4; I have this input: its the bluetooth connection. I'm using a Mid 2011 MacMini with BT keyboard and BT trackpad.

I've purged several "processes" and used disc Utility to correct permissions, and corrected an issue with Time Machine external drive (it sometimes didn't mount correctly and Spotlight would hang indexing) ...

Both the keyboard and trackpad would be working fine, until I connected my BT Motorola H390 headset or Patrionics BT headset. The audio is horrible and the trackpad immediately becomes erratic.

No more BT headset! Sprung for the In-Ear Headphones. Well worth it.

I'm on a MacBook Pro mid 2012, Yosemite with an external monitor. The magic mouse was ungovernable, either with the monitor connected or not. I bought an external bluetooth dongle but it didn't solve the problem.

After restarting in safe mode it was working fine. Then I repaired permissions and restarted, it seems to be working better, not sure if 100% but much better. I got some lag when loading a website, but during graphic work it seems to work fine.

Thanks Linc, great answer.

Reporting one day after: It's impossible to work with this mouse again.

I've seen posts from 2009 reporting this problem and Appe still does nothing about it. New iPhones and watches but the can't make a mouse work fine.

Excellent Apple, great job.

You should always try repairing disk permissions before any of these steps.

I have had this issue happen twice now with my 15" MacBook Pro Retina. For the first occurrence, the erratic behavior started suddenly in the middle of using my Mac, no inciting event. For the second occurrence, it started after I cleaned my trackpad with eyeglass cleaner.

BOTH times the solution was to repair disk permissions and restart my laptop. I'm not too terribly sure why or how cleaning a trackpad causes disk permissions errors but it did the trick. This solution wasn't listed so I thought I'd provide it.

Unplug external drives connected to USB.