Introduction

There is a great deal of confusion in the DSM community about how the engine control unit (ECU) actually operates, and why it operates the way it does. Although this information is readily available, the terminology used is unfamiliar to some, which leads to significant misunderstandings. This document is intended to provide all the requisite information necessary to properly understand the ECU and it's operation on the DSM vehicles.

For those who are familiar with this information and want more details, you will need to get the $2 DSM Technical Manual. All of the information you could ask for is contained in this reference, and I'm not attempting to duplicate it here. Get it at the Backup Manual CD home page.

Table of Contents

1. Open-loop systems
2. Closed-loop systems
3. Closed-loop operation on DSMs
4. Open-loop operation on DSMs
5. Determination of open vs. closed loop operation on DSMs
6. Open-loop operation on modified vehicles
7. Fuel cut in the DSM ECU

This document was last updated on November 03, 2001.