Break System light on after checking fuses

[AlexO]

I had a strange thing happen yesterday and hope someone here can help me troubleshoot.

It started with me trying to figure out why my AC doesn’t put out much cold air. It’ll barely keep the car cool in 75 degree weather. Anything above 75, it struggles.

I started by checking any AC related fuses in the under-hood fuse box. Pulled fuses A6, A16, and A41, saw that they are good and put them back.

When I started the car I now have a Brake System light on. Scan tool brings up DTC U0129 F-can Malfunction(ECM/PCM-Servo Unit).
Attached are images from the scan tool.

If anyone is able to guide me on some troubleshooting I will be very grateful.

Thank You

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[ModJPB]

Did you try clearing the ECU codes? A lot of the times the ECU triggers a code just by simply unplugging and plugging things in. It's only an issue if the code comes back after you clear/reset the system.

 

[AlexO]

Yes, I reset the ECU with the scan tool and disconnected the battery for several hours (I believe that also resets the ECU).
The code still comes back.

 

[Victorofhavoc]

Yes, I reset the ECU with the scan tool and disconnected the battery for several hours (I believe that also resets the ECU).
The code still comes back.

The servo error is for the epb most likely.

Try engaging and releasing it a few times. Go for a drive for 25mi, then try to clear again.

Did you unplug the battery while checking the fuses? With modern cars it's basically a requirement to do so, especially since the vehicle is looking for the epb signal to be constant.

It's also possible a fuse blew after being placed back in if battery was plugged in and sometimes they don't even look blown. A multimeter or ohmmeter would help verify it.

 

[UWU-mancer]

The servo error is for the epb most likely.

Try engaging and releasing it a few times. Go for a drive for 25mi, then try to clear again.

Did you unplug the battery while checking the fuses? With modern cars it's basically a requirement to do so, especially since the vehicle is looking for the epb signal to be constant.

It's also possible a fuse blew after being placed back in if battery was plugged in and sometimes they don't even look blown. A multimeter or ohmmeter would help verify it.

This. Disconnecting the battery before removing fuses on a modern car is the best play

it’s ok tho. At least your car isn’t German.

 

[AlexO]

Unfortunately I pulled the fuses with the battery connected. I looked through a service manual from a 24 Civic and this same code comes back as an issue with the electric vacuum pump.
I see that I have a vacuum pump but there is no fuse in the EVP slot.
Is this normal?

 

[Victorofhavoc]

Unfortunately I pulled the fuses with the battery connected. I looked through a service manual from a 24 Civic and this same code comes back as an issue with the electric vacuum pump.
I see that I have a vacuum pump but there is no fuse in the EVP slot.
Is this normal?

It's not the vac pump if you're getting the brake light and servo dtc. I'm 99% certain it's an epb malfunction dtc. Have you tried resetting the epb?

Keep in mind Honda does silly things with wiring. Diagnosing Honda fuses is like trying to figure out why your turn signal turns on the wipers and turns off a headlight in a corrado.

There's also a main fuse in the wiring attached to the battery I believe.

 

[AlexO]

According to this, the vac pump will light up the brake system light.
For some reason, when I try to open the EVP system on the scan tool, it tells me the system is not available. Maybe I need HDS for this?

Also, when I start the car, I don't feel it running; no sound from it and no vibrations.
Maybe, if someone has time, they could check on their Integra if there are obvious signs of it working.

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