Tach Gone Crazy! Need Help
 

Hello everyone, I am super new. Just bought my BRZ and this has been a dream car for a long time. It is a 2013 BRZ with manual transmission. The issue I have been having is that about 50% of the time when I start the car up the idle RPM reads really high (like above 4500 RPM). Its idling where it should be but it's reading very high. As I rev it up it continues to climb way past redline and sometimes around to the ODO. I have been doing a lot of research and can't find anyone that is having the same issue. Also the other half of the time when it reads correctly it seems to be dead on. It seems strange that none of the other gauges are messed up at all. IDK what to do. please help.

The first pic is at idle and the second pic is about mid rpm. (obviously not 12,000)

i'm gonna take a guess on this.
I think the needle is just misaligned or loose from it's mounting.
You can probably take it apart and align the needle.

or just replace it as a whole assembly.

Welcome to the group!

Oh, I hope the engine isn't running at the indicated RPM?

Assuming it's not, I reckon a tune-er or the dealership should take a look see and see what is whacked out.

Or you could try disconnecting the battery for a minute and hook it back up, to see if the ECU will right itself.


humfrz

Do the RPMs stay high all the time after you start the car or settle later? Does turning car off/on fix it?

Connect an OBD2 cheap adapter and see if the RPMs show correctly on the adapter vs. the cluster. If that is the case, you probably need a new cluster (ECU output is the right RPMs but the cluster is not delivering them right).

I rule out a misaligned needle because in that case you'd have a faulty RPM reading all the time, not 50% of the time.

If it's not isolated to the cluster, you have an electrical problem and those can be a pita to find.

There appears to be tool marks above the speedometer so I would suspect that cluster has been out for one reason or another. You may want to look into that, maybe there's a loose connection back there.

Most modern clusters are on the canbus, so it's possible to read internal faults, command the stepper motors and test display segments.

Checking that would be my initial instinct.

I'm having this issue too. Was just trotting around town when my tach became offset by 3000rpm. Is there anything I can do short of bringing it to the dealer?

You might disconnecting the battery for a few minutes to see if the UCU will re-set it - :iono:

Bubba suggests to rap on the face of the dial with your right hand middle finger's knuckle to see if it's stuck.

(don't be maken fun of Bubba, till you have drank as much beer as he has)

bubba's info was accurate for the time when the gauges were operated by spinning cables. it's no longer the case though!

Thanks, I'll let him know - :D

After that happened I kept on shutting down and restarting the car with no success, so I left for dinner. I came back to my car after a few hours and the needle was fine... Maybe it needed a reboot.