Latest Software Upgrades

[CCR91]

Hello,

I have a 2001 that I purchased in Nov 2000. I just moved from Hawaii to Virgina and noticed that on cold mornings the idle has a bit of a surge. I also have the downshift to fourth when towing with crusie control problem. Would a software flash fix these and be covered under the 5-yr/100,000 mile warranty? I only have 43,000 miles on it.

Thanks.

[01max]

there were a few updates for the engine and updates for the trans. when you say you down shift to 4th how do you do it? If you move the gear selecter down one gear you go into 3rd. the 01 &02 cannot select 4th unless the truck has had a manual button installed. also a slight surge is normal if its under 100 rpms, if it's over that it may have a bad fuel pressure regulater

[mark45678]

this maybe covered but even if its not it will only take a TEC 20 mins with a test drive to cure your complaints!

My 2001 GMC lb7 had the same exact problems, with cruise on the trans down shifted way to easy in to 4th when it was pulling a grade.... with updated software this is much better. the surgeing is about cured but not 100% , its liveable once the update is done.

[mark45678]

FYI the early 2001 duramax trucks had a small problem with the air box , there is a piece of foil tape that can cause a blockage so its suck air in and water was getting in it also. I drilled holes in the bottom of mine so the water didnt collect and to let air in if the foil tape was to block the opening. I think the updated air box had the hole side opened up much bigger then the early 01's

[DmaxMaverick]

Originally posted by mark45678:
FYI the early 2001 duramax trucks had a small problem with the air box , there is a piece of foil tape that can cause a blockage so its suck air in and water was getting in it also. I drilled holes in the bottom of mine so the water didnt collect and to let air in if the foil tape was to block the opening. I think the updated air box had the hole side opened up much bigger then the early 01's The 2001's had a snorkel that went into the fender. No mastic (foil tape). Problem was, the snorkel allowed water into the air box from the fender. The fix was to replace the air box with one that had a large opening on the fender side, and the fender hole covered with the mastic. Later, we found the mastic could come loose and get sucked into the air box, blocking the air filter.

On mine, I "Swiss-cheesed" the bottom of the air box, removed the snorkel, and left the hole in the fender uncovered. The air channel in the fender gets fresh air (and water) from behind the headlamp ass'y. Since, I've never had a problem with a wet filter, in any weather condition.

There were several program updates released for the 2001. Many addressed shifting, drivability, idle smoothness, and cruise control performance. If it's never been flashed, you should have it done. The most it should cost you, if it isn't covered by your dealer, would be less than an hour of shop time. It should take a good tech less than half an hour to do it.

[CCR91]

Thanks for the help. I will have to make an appointment to have it fixed.

01Max, I don't manually downshift to 4th. When using the cruise control the transmission automatically downshifts to 4th as soon as the slightest decrease in speed is detected. Intstead of downshifting, the motor should pull the load in 5th. This only happens when using cruise control.

[Buck]

When I had my 2001 Dmax updated for the cruise control thing. After the update, it allowed for a 4 mph drop before downshifting. Before the update it would downshift with a 1-2 mph drop.

[DmaxMaverick]

Originally posted by CCR91:
......When using the cruise control the transmission automatically downshifts to 4th as soon as the slightest decrease in speed is detected. Intstead of downshifting, the motor should pull the load in 5th. This only happens when using cruise control. One of the updates addresses this specifically. After the update, you should have a 4 MPH window with a time delay before downshift.

Also, it doesn't hurt to anticipate a grade by feeding the pedal a little to spool up the turbo to increase the power response. Turbo lag makes the issue worse, as by the time power shows up, you've already lost enough speed to force a downshift.