9/14/11 - See this thread for resolution.

8/21/11 - Update at bottom of thread.

I've been getting an intermittent SES, and finally pulled the codes last night. (With my brand new copy of AE from Clay!) Anyway, I think the light is coming from a P0107, which looks to be a failure of the barometric pressure sensor. On the PCM. (And another little piece of me dies...)

The fix appears to be replacing the PCM. Where can I get one of these and, more importantly, where can I get on that matches my code (EBM2), for which my F5 from Jody was tuned? Would Rockauto have something like this?

Second, Diane mentioned that some places repair PCM's. Do any of you know who might do this?

Lastly, can I drive the vehicle safely? I'm planning to take it to the hills (altitude from 5000 - 11000ft). If I run it in stock tune, or maybe 40T, I'm thinking it wouldn't overfuel too badly. (Diane mentioned this failure is likely the cause of the smoke I'm seeing off idle and on low rpm shifts in 80e. I assume it's overfueling because the PCM thinks I'm at a different altitude, and likely a lower one.)

Thanks!

Mark

 

The barometric pressure sensor in the 99-03 PCM is part of the circuit board. If it has failed, then the PCM must be fixed or replaced.....and I am unaware of anyone that will fix your existing PCM.

A P0107 will cause a very harsh upshift concern due to full transmission line pressure being commanded. It's not the best thing in the world for the vehicle, but that's the only noticeable symptom you should have.

 

Mark,

This just hit me. Contact Rocky Horn at Rockin S diesel. He may have a contact in CO or contact Tom S by pm. There's a guy I know who lives in Co who might tackle the repair. I will email him. Replacing the PCM will be your best bet.

Diane

 

Here you go, looks like there is one right in Denver 20 min from you that you could snag. I have grabbed them before for as low as $75 so just try and talk them down.

 

Maybe this place can help.
Auto Computer Exchange | Engine & Transmission Control Units

 

Duh. I should have thought of Rocky, too. I talked to him this afternoon, and he's looking around. Left a note for Tom, too. Thanks!!

I called these guys, and may yet stop by there. The guy tried to tell me there was no such code as EBM2, which made me nervous. Lovin' that AE from you, though. I'd have never found the problem if not for that tool. I'd have been bugging Diane about smoke forever.

Good suggestion. I'll try these guys if Rocky and Tom aren't able to help.

Thanks!!! This is an amazing place.

Mark

 

I had a bad experence with auto computer exchange. Check their rating with better business. Also check google under auto computer exchange complaints.

 

There is I assure you. Just go in like you own the place and don't listen to them

 

There certainly is an EBM2.

<TABLE dir=ltr border=1 cellSpacing=1 borderColor=#000000 cellPadding=12 width=863><TBODY><TR><TD height=0 vAlign=center width="7%">CODE
</TD><TD height=0 vAlign=center width="7%">YEAR
</TD><TD height=0 vAlign=center width="11%">CALIB.
</TD><TD height=0 vAlign=center width="9%">MODEL TYPE
</TD><TD height=0 vAlign=center width="10%">ECM PART Number
</TD><TD height=0 vAlign=center width="27%">APPLICATION
</TD><TD height=0 vAlign=center width="20%">MODULE APPLICATION
</TD><TD height=0 vAlign=center width="10%">TEMPLATE
</TD></TR></TBODY></TABLE>
<TABLE dir=ltr border=1 cellSpacing=1 borderColor=#000000 cellPadding=12 width=863><TBODY><TR><TD height=0 vAlign=bottom width="7%">EBM2
</TD><TD height=0 vAlign=bottom width="7%">2001
</TD><TD height=0 vAlign=bottom width="11%">1L119Y0B10
</TD><TD height=0 vAlign=bottom width="9%">DPC-452
</TD><TD height=0 vAlign=bottom width="10%">1C3F-XC
</TD><TD height=0 vAlign=bottom width="27%">

7.3L EXCURSION DIESEL - AUTOMATIC

</TD><TD height=0 vAlign=bottom width="20%">

50S

</TD><TD height=0 vAlign=bottom width="10%">

VRAA7Y5

</TD></TR></TBODY></TABLE>

There is also an EBM0, EBM1, and EBM3.

 

Yeah, I read it right off the PCM sticker...

So, I drove 150+ miles tonight, with 4-5 restarts, and had no SES issues, and no smoke. I ran it in stock tune, and it ran like, well, it ran like a ScaldedDog. I don't think Jody's "stock tune" is exactly stock. I could never hit 20psi at 8000ft with my old stock tune...

Mark

 

Update: I drove it, in stock tune, 360 miles over the weekend, with 20+ key cycles. No SES light, almost everything worked fine. The exception was, out of the blue, it wouldn't go into 4hi or 4lo, after one ten mile drive, despite repeated attempts. Tried it again after a few hours and another ten mile drive, it went in fine, and has done so several other times since. No SES or flashing OD light at any time.

I read the codes tonight, and found these:

P0107 - MAP/Barometric pressure sensor
P0500 - VSS/overhead console
P1832 - Transfer case diff lock failure

These were the same set of codes I had the night I started this thread, and I think they are the same ones a friend read back in early June right after the SES light came on the first time. I'd assumed the P0500 was from having a chip, but a little research tonight tells me that's not likely the case.

What's going on? I suppose I could have three totally unrelated sensors going bad at the same time, but intermittently. On a hunch, I took the piece of crap O'Reilly Ultima alternator I'm running in for testing tonight, and it passed three times. (I'd replaced a bad O'Reilly Autolite alternator in April.) Still, I'm wondering if an intermittently bad diode (is that even possible?) might be allowing noise back into the system.

Any ideas? I'm at a bit of a loss...

Thanks,

Mark

 

I'm still troubleshooting this, and I've started checking codes after each trip to see if all three of codes above always occur together, or separately and randomly. So far, they haven't reappeared, at all.

For anyone with AE, though, I have a question: What voltage does it show in the live data graph when "vehicle voltage" (or something like that - it's not in front of me right now) is selected? Mine shows 11.75 with the motor off, and max of 13.8 when the motor has run awhile. My voltmeter connected to the battery shows 14.4 in the running case, which I think of as normal. Are the AE values I'm seeing also normal?

Mark

 

9/14/11 - See this thread for resolution.

8/21/11 update - DP and Tom S from our local club have been helping me troubleshoot this, but, I'm still having weird issues, and they are both traveling today, I think. I now a have a specific question:

What can cause a P1397 on these rigs?

I swapped the alternator pigtail Friday night (just in case) and had the batteries disconnected. Had several engine starts and/or key cycles Friday night and yesterday, including an hour and a half tow with no issues. Last night I cycled the key a few times in the evening, with no SES light.

This morning I went to start the truck and, sure enough, had an SES. AE found a P1397, but describes it as having something to do with variable valve timing. Clearly it doesn't mean that on these trucks, but references to PSD's and that code have to do with voltage irregularities during KOEO tests, which I didn't perform. Ideas?

If you read through this entire thread you'll find I've had several seemingly random codes - P0107 (twice), P0500 (once), P1832 (twice), P1000 (nearly every time I check, no matter how long it's been since the batteries were disconnected, including this morning.)

Mark