Intro - Tooth Logger - Tooth Logger - Composite Logger - Sync Error Logger Examples page

Introduction

Within the MS2/Extra code there are four internal tooth/trigger loggers for diagnostics. They can record 341 samples of information, which equates to a number of revolutions of the engine and is typically a handful of seconds of data. Be sure you are using firmware 2.1.0 or newer (e.g. 3.2.1) to have full support.

All of these loggers are supported by TunerStudio which enables the logger within the MS2, fetches the data and gives a visual display. To access these, click on the Diagnostics tab and then choose your logger.

Tooth logger

This records the tach events that are received by the main tach input (crank) after any noise filtering. The height of the bar on the screen represents pulse length. The taller the bar, the longer the pulse.
(It does NOT give any information about the analogue voltage coming from your crank or cam sensor, if you need to examine that you will require an oscilloscope.)

TunerStudio Screenshot of simulated 36-1 signal on bench.


In the above 36-1 screenshot you can see 34 normal teeth and the single long "missing" tooth.

TunerStudio Screenshot of real 60-2 signal during cranking with compression effect.


In the above 60-2 screenshot you can see 57 normal teeth and the single extra long "missing" tooth. The cyclic nature of the teeth is due to the engine speeding up and slowing down during cranking. The OEM has place the missing tooth in a good place to avoid confusion with the compression effect. With poor choice it can be difficult for the code to reliably detect the tooth.

Trigger logger

This records the 'decoded' and filtered tach events and is one pulse per normal ignition event.

Composite logger

The basic tooth logger records enough information to analyse a typical missing tooth wheel on the crank. However, if the engine uses both cam and crank sensors, then a new logging method is required. This third 'composite' logger records both crank and cam signals and under some circumstances it will record both edges of the input signal. It could be used as a crude two channel oscilloscope.

This log shows Subaru 6/7. This is a 'single edged' signal so the visualisation can only show a point/line.

This log shows an example 'double edged' signal with some noise.

TunerStudio Screenshot of simulated LS1 crank and cam signal.

Sync Error Logger

This is a variant of the composite logger. During normal engine operation it will show nothing at all, but if a sync-loss event occurs (due to noise) it shows the tooth pattern that led up to the loss of syncronisation. This allows you to pinpoint the problem without searching for the needle in the haystack as would be the case trawling through large composite logs.
To use this logger, it is usually useful to capture to a log file. Tick the "Capture to log file" box and save the filename. Then start the sync error logger and drive or ride around. (You can datalog at the same time.) When you have finished, Stop the logger and un-tick the "Capture to log file". Then review the captured data or post it on the support forum.

Examples page

For many more real-world examples of tooth logs - see the examples page.

If you have a question, comment, or suggestion for this FAQ please post it on the forum.

No part of this manual may be reproduced or changed without written permission from James Murray, Ken Culver and Philip Ringwood.