# Service bulletin SF633

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 10222236
- Published by NHTSA: 2022\-10\-04
- Manufacturer's number: SF633
- Manufacturer's date: 2022\-09\-26
- NHTSA component: PARKING BRAKE

## NHTSA's summary

Revised Field Service Campaign for FCCC School Bus Chassis Park Brake Alarm. On certain vehicles, the park brake alarm software parameter may be disabled. With a disabled park brake alarm, if the driver turns off the ignition without setting the park brake, the park brake alarm may fail to emit an audible sound. REVISION: Due to a software parameter change that was not updated at the host, the SF633 repair provided during August 2021 through August 2022 was not adequate. The host has been updated and the repair will now rectify the issue. SF633 has been re\-released with a new termination date of September 30, 2023.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2022/MC-10222236-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2022/MC-10222236-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Brakes, Parking brake

## Vehicles listed

- 2021 to 2022 THOMAS BUILT BUSES SAF\-T\-LINER C2

JSON: [/v1/bulletins/10222236](/v1/bulletins/10222236)

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