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View Full Version : Problems with B1501 set to 'Disable'



jpgmtech
February 22nd, 2010, 07:05 AM
Hi All!

Just spend the better part of a couple of weeks isolating a real hair-puller. This applies to trucks running OS 12628954, affects LMM's from 2007-2010 (verified)

Condition: Setting 1501 EGR Control to 'Disable' has the following effects which seem to manifest themselves after the engine is warmed up or after a prescribed run-time:
• Injection timing surge
• Turbo pressure and vane surge, both on cruise and acceleration
• Intermittent extremely black smoke on shifts (suspect this is the EGR valve physically opening even though my logs do not show it.)
• Intermittent lag on acceleration

What appears to happen is the turbo and injection timing modes seem to cycle back and forth with some kind of phantom EGR mode, causing the surging and intermittent black smoke.

I have several logs that capture the surging condition if anyone wishes to look at them. Originally I backdated a few trucks to one of my older tunes until I had the time to isolate this. I just finished A-B-A testing on two different trucks. I have only used B1501 recently, most of my LMM tunes disable the EGR with the original methods - setting B1502-1506.

Bottom line - leaving B1501 in stock position 'Enable' will solve a number of phantom problems with LMM tuning.

duramaximizer
February 22nd, 2010, 09:52 AM
Yep, you have to go through and set the EGR parameters to these:

I set all EGR flow data in tables 1526, 1527, 1528 to "0."

B1501 Enable
B1502 -100.000000
B1503 320.000000
B1504 -57.932176
B1505 -2.900000
B1506 -100.000000
B1520 300.951932
B1521 302.000000
B1522 300.951932
B1523 302.000000
B1524 -57.932176
B1525 302.000000
B1529 6000.000000
B1530 5999.000000
B1531 284.000000

killerbee
February 22nd, 2010, 11:16 AM
A big high 5 Joel!

jpgmtech
February 26th, 2010, 05:23 AM
Hoping it saves some grief. I've noticed in other forums that a few guys have been setting B1501 to 'disable'. In one post, the guy noted that his tune had a couple of glitches much like the symptoms I described.

Had at least two guys up here wondering if I knew what I was doing when I had to take a few hours on their trucks instead of the usual 30 minutes. Not good for my customer base to see glitches like that, it hurts their confidence. Still, they are happy with the results!

duramaximizer
March 1st, 2010, 12:02 PM
Hoping it saves some grief. I've noticed in other forums that a few guys have been setting B1501 to 'disable'. In one post, the guy noted that his tune had a couple of glitches much like the symptoms I described.

Had at least two guys up here wondering if I knew what I was doing when I had to take a few hours on their trucks instead of the usual 30 minutes. Not good for my customer base to see glitches like that, it hurts their confidence. Still, they are happy with the results!

Ya no shit. :secret:

killerbee
March 24th, 2010, 06:47 AM
B1526-B1528 do not appear to function either, if I understand them. Are they suppose to stop egr opening when set to 0? I see no difference after entering all zeros.

JoshH
March 24th, 2010, 08:02 AM
I've not experienced any of the problems you state by setting that table to disable with that OS. Were you doing that in addition to changing the other tables, or were you trying to disable the EGR with just that enable/disable button?

jpgmtech
March 24th, 2010, 08:16 AM
I've not experienced any of the problems you state by setting that table to disable with that OS. Were you doing that in addition to changing the other tables, or were you trying to disable the EGR with just that enable/disable button?

I had set B1502-B1506 to disable EGR function originally, and the tunes I had problems with; I additionally set B1501 to Disable. I had in mind to shut down the EGR cleaning cycle that occurs after engine shut down, and that did fix that but introduced all of the above problems. I'm still cleaning up the odd truck that had B1501 set to Disable up here, including one today.

It could be that simply changing B1501 to Disable without changing any other parameters might be sufficient and may not demonstrate the problems listed above.

jpgmtech
March 24th, 2010, 08:17 AM
B1526-B1528 do not appear to function either, if I understand them. Are they suppose to stop egr opening when set to 0? I see no difference after entering all zeros.

I can honestly say I never have touched those parameters to even know.

JoshH
March 24th, 2010, 08:48 AM
I had set B1502-B1506 to disable EGR function originally, and the tunes I had problems with; I additionally set B1501 to Disable. I had in mind to shut down the EGR cleaning cycle that occurs after engine shut down, and that did fix that but introduced all of the above problems. I'm still cleaning up the odd truck that had B1501 set to Disable up here, including one today.

It could be that simply changing B1501 to Disable without changing any other parameters might be sufficient and may not demonstrate the problems listed above.
Hmmm, weird. I have done exactly what you said, and never experienced those problems. I have tried setting just the enable/disable to disable, but that doesn't disable the EGR (or at least it didn't for me).

killerbee
March 24th, 2010, 09:25 AM
B1526-B1528 do not appear to function either, if I understand them. Are they suppose to stop egr opening when set to 0? I see no difference after entering all zeros.

I should add to this. All zeros in the scheduling tables does create big problems, anomolous spotty chugging and ecm confusion, if leaving the EGR enabled in the parameters section. EGR position would go to 40%, reducing fresh air (maf) by 80%, and I think the fire started to go out.

Restoring the stock, non-zero values appears to have fixed it.

blaineGMC
November 18th, 2014, 04:00 AM
Yep, you have to go through and set the EGR parameters to these:

I set all EGR flow data in tables 1526, 1527, 1528 to "0."

B1501 Enable
B1502 -100.000000
B1503 320.000000
B1504 -57.932176
B1505 -2.900000
B1506 -100.000000
B1520 300.951932
B1521 302.000000
B1522 300.951932
B1523 302.000000
B1524 -57.932176
B1525 302.000000
B1529 6000.000000
B1530 5999.000000
B1531 284.000000

Those tables said they were out of Range.. This is how mine Came out . Am I doing something wrong?
Enable
100.000000
160.000000
57.926890
-2.900000
100.000000
150.000000
150.000000
150.000000
150.000000
57.926890
150.000000
6000.000000
5999.000000
120.920590

Mitco39
November 18th, 2014, 06:22 AM
Since that post is over 4 years old its possible that the calz files have changed since then and thats why they are different.

blaineGMC
November 18th, 2014, 06:39 AM
Since that post is over 4 years old its possible that the calz files have changed since then and thats why they are different.

Do those figures I have look like they will work?

DURAtotheMAX
November 18th, 2014, 07:12 AM
Its been a while since I have custom tuned an LMM in person...and I dont have access to one right now to verify, but the last one I tuned, I have all of the desired flow tables zeroed out, and B1501 set to disable. All of the other EGR tables are set to prevent the ECM from even trying, IE, temperature and RPM values set to almost maxed out.

The only tables I left stock are the EGR minimum/maximum duty cycle tables.

That seems to work fine for me......no issues or codes.

Ben

blaineGMC
November 18th, 2014, 07:31 AM
Its been a while since I have custom tuned an LMM in person...and I dont have access to one right now to verify, but the last one I tuned, I have all of the desired flow tables zeroed out, and B1501 set to disable. All of the other EGR tables are set to prevent the ECM from even trying, IE, temperature and RPM values set to almost maxed out.

The only tables I left stock are the EGR minimum/maximum duty cycle tables.

That seems to work fine for me......no issues or codes.

Ben

Anyone see a problem with this?17686

jay p
November 18th, 2014, 09:06 AM
Yes, the temps need to be above/below a temp the engine will see.

example: Min engine temp should be higher than the engine will ever see to keep EGR off ( like 300 deg). and Max engine temp should be opposite (-57 deg).

If you do that for all the temps, EGR should never turn on. I leave the cooler rpm settings and temp setting alone. I also leave the shutoff position and duty cycle settings alone.

Jay

blaineGMC
November 18th, 2014, 09:10 AM
Yes, the temps need to be above/below a temp the engine will see.

example: Min engine temp should be higher than the engine will ever see to keep EGR off ( like 300 deg). and Max engine temp should be opposite (-57 deg).

If you do that for all the temps, EGR should never turn on. I leave the cooler rpm settings and temp setting alone. I also leave the shutoff position and duty cycle settings alone.

Jay

It doesnt allow me to put the tables that high.

DURAtotheMAX
November 18th, 2014, 10:14 AM
It doesnt allow me to put the tables that high.

Do you have the units set to standard/US....?

blaineGMC
November 18th, 2014, 10:29 AM
They were metric.. Now I changed it to US and I was able to use Duramaximizers figures, Thanks Ben!