× Auto Repair Pros Member Benefits TechHelp Knowledge Base Forums Resources My iATN Marketplace Chat Pricing About Us Join Industry Sponsors Video Members Only Repair Shops Auto Pro Careers Auto Pro Reviews
Join Now
International Automotive Technicians Network
The power of built in scan tool functions
Posted to Technical Discussion Forum on 6/27/2013 47 Replies

I had a 2005 Ford Taurus come my way requiring a drivability diagnosis. It had a dead misfire, and even taking the misfire into account it was idling very poorly. I checked Continuous Mode DTCs, the P0171 Freeze Frame, and PCM KOEO codes . There are many ways to handle this vehicle, but I'll share what I did with my IDS.

First, I checked power balance. Next, I checked relative compression. I then checked relative injector flow. I was already in the Fuel System tests, and I did have a P0171 so I thought I'd just check running fuel pressure and fuel pressure leak down really quickly. I already knew where I was going for the misfire, but before I got out of the driver seat I thought I'd just peek at some scan data.

At this point I already know I have an ignition system related misfire. Not hard to guess, certainly not hard to determine through other methods. I was able to quickly eliminate/confirm a variety of things and narrow my testing down to the most pertinent area.

I put my capacitance pickup on cylinder #3's ignition cable and checked Power and Waste secondary waveforms. The spark is not occurring in the combustion chamber. I put a spark tester set to 20kv on the end of the ignition cable, and a low amp probe around the coil common power wire. No spark at the spark tester.

100k on the odometer, original plugs, orginal ignition cables, and a defective coil. A set of plugs and cables, with a new coil and the misfire was corrected. A KAM Reset, fuel trims back to normal, misfire gone, and away goes the vehicle: fixed.

This was not a complicated failure, nor a complicated diagnosis. This vehicle certainly could have been diagnosed a number of ways utilizing a wide variety of tools and/or methods. Still, the power of the built in test functions of the Ford IDS for this vehicle made it a no risk, low effort, high comfort diagnosis.

Shannon from California

Files Referenced:

thumbnail thumbnail thumbnail thumbnail thumbnail thumbnail thumbnail thumbnail thumbnail thumbnail thumbnail thumbnail thumbnail

47 Replies Received (View Replies)

 

car Vehicle Data

2005 Ford Taurus SE 3.0L

Engine3.0 L
Trans4-speed Automatic (Electronic)

car Vehicle Data

2005 Ford Taurus SE 3.0L

Engine3.0 L
Trans4-speed Automatic (Electronic)