# Service bulletin 19\-TR\-19EN

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: 10163635
- Published by NHTSA: 2019\-08\-12
- Manufacturer's number: 19\-TR\-19EN
- Manufacturer's date: 2019\-07\-10
- NHTSA component: ELECTRICAL SYSTEM:SOFTWARE

## NHTSA's summary

Service tip for the optional Preselect Optimization feature. The transmission will not initiate preselect downshifts when the engine brake is active, unless the service brake is simultaneously depressed. Correction: If closed throttle Engine Brake Preselect downshifts without depressing service brake are desired, then the ENGINE BRAKE: Automatic Preselect Optimization \(CMC\) setting must be changed to NONE using the reprogramming function in Allison DOC® \(see Figure 1\). The TCM will revert to the defined Engine Brake Interface, Input H / Output A or Input I / Output A parameters. The Engine Brake Automatic Preselect Optimization logic will be disabled. Grade Braking Automatic Preselect Optimization and Cruise Control Preselect Optimization will be unaffected

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2019/MC-10163635-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2019/MC-10163635-9999.pdf)

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

## Components

Electrical system, Software

## Vehicles listed

- ALLISON TRANSMISSION

JSON: [/v1/bulletins/10163635](/v1/bulletins/10163635)

[Report an error on this page](https://github.com/wenmar-pro/wenmar-open/issues/new?template=data_correction.yml&title=Data%20correction%3A%20Service%20bulletin%2019-TR-19EN&page=https%3A%2F%2Fopen.wenmarpro.com%2Fbulletins%2F10163635&vehicle=Service%20bulletin%2019-TR-19EN)