You would think that if a customer rolled in with a vehicle that had been to other dealerships

four times to solve an illuminated MIL concern, that the service writer would be smart enough

to get some time on the job. But no… not this one… Yes Sir! We can fix it while you wait!

Thanks a lot…

So lets look at it…

Now don’t let the “2000” throw you. This truck uses the same 7.4L engine as the 96’s. I drove it to my stall and noticed nothing unusual (seemed to drive ok) except, of course, the service engine soon lamp (MIL) was on.

First step today is to hook up the Tech 2 and see what codes are stored…

Ok, the DTC that illuminated the MIL was a P0446. But we also have a P0102 that set sometime after the first failure (and set failure record) for the P0446. Now we need to take a look at the DTC Info screens. After that, we need to view the Freeze Frame and Failure Record data. Hold off on digging out those books and looking for enable criteria… Leave that for the experts who don’t fix cars for a living <g>

So here we have two basic problems.

· · The Evap system is not venting properly

· · The MAF frequency output is too low.

I have gone over what the above parameters mean before so I won’t do it again today. But please take

special notice of the “Since Clear” section and then later watch for Pass and Fail Counters. Now its time

to view the Freeze Frame Data:

Now how about the Failure Record Data starting with the same P0446:

	I would think these screens should put to silence those experts who will tell you to buy their enable criteria books and RUN THEM MONITORS! For crying out loud… can’t they see how futile that becomes? But no, they will keep preaching the same old thing… They don’t have to fix this stuff…. <g> Sorry for the editorial here… I had to fill some white space since this had 3 pics… <bg>

Now lets move on to the P0102 Failure Record Data

	Oh crap… more white space to fill… Lets see, what do we have here? I would have thought I would have seen at least 1 pass count. Do you think this DTC was present when it was at the other dealers? Why or why not? When and under what conditions did this code set? Do you still feel that Freeze Frames and Failure Records are not of much value?

Well, lets look into that P0102 first; the P0446 might get ugly.

Good! Nice and easy. The MAF connector as you can see is not fully snapped into the MAF sensor. That ought to be worth at least 2/10 warranty pay… Lets move on to the P0446. I think I’ll start off with taking a snapshot and plotting the fuel tank pressure to see how the system is purging and venting.

The downward trend is when I had the engine cranked up and the evaporative system was purging normally (vent open). When tank pressure hit – 5 in H20, I let up and the system started venting (no purge and open vent). Note: Except for the text on the graphic, this is an actual picture of the Tech 2 screen after I ran it thru a few color filters. What do we do now? It seems to be venting ok? Oh yes, I’ve gone down this road before; I know what I’m gonna do. Do you??

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