Finding Misfires On pre-CAN Fords Using Mode $06

Finding Misfires On pre-CAN Fords Using Mode $06

Motor Age — Do you remember the days of OBDI? For those too young to remember, it was an era plagued with vague codes definitions, plenty of “ghost” codes, limited data access and a lack of standardization among the manufacturers. Many scan tools still offer OBDI connectors (there seemed to be hundreds!) but I found it just as easy to retrieve codes manually rather than clog up my toolbox with them. Out of necessity, we found alternative ways to troubleshoot these early systems and used them often enough to keep them fresh in our memories. As OBDII moved onto the scene, many of these same techniques carried over while others did not. And you know what they say, right? A skill learned and not used is a skill soon forgotten.

OBDII brought with it more diagnostic resources and some standardization across the OEMs. “Global OBDII” and its nine (now 10) “modes” provide access to information deemed necessary to troubleshoot and repair any fault that would result in increased emissions. Many of these modes you use on a daily basis. For example, mode $03 (the “$” indicates a hexadecimal number) is where you go to see what turned the Malfunction Indicator Lamp (MIL) on while mode $04 is the mode you use when you clear the codes and reset the MIL. Other commonly used modes you may know by a different name are mode $01 (live data stream), mode $02 (freeze frame data) and mode $07 (pending codes).

The mode we’ll be discussing in this edition of the Trainer is mode $06. This mode provides access to the results of all the tests the Engine Control Module (ECM) performs on its non-continuous monitors. Don’t worry, we’ll explain what that means in the video too! Mode $06 became popular when diagnosing misfires on Ford products that had not misbehaved enough to turn on the light and has since been used by many techs for troubleshooting a variety of complaints. And while the growth of Controller Area Networks (CAN) has made the live scan data more complete, some of the old techniques we used utilizing mode $06 are still worth practicing.

Source: Motor Age