2008 ly6 w/6l90e - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**shadow1967** · 07-21-2015, 08:03 PM

I have a ly6 w/6l90e trans. Trans is out of a different truck than the engine. there was a problem with the pump so they sent a different trans with the engine. So my problem is engine runs great , ran it for 15 minutes and the heads never went above 217* So that's great, Now the BUT, it will not go into gear. Someone said The trans tcm needs to be reprogrammed as well. is this correct.
Thanks in advance

clinebarger · 07-21-2015, 08:51 PM

Yes, If the Trans is not from the same vehicle as the ECM, The TCM & ECM will not Communicate with each other. The TCM will go into a Default/Limp mode, But the vehicle will still move, But will shift really weird.

What codes are present in the TCM & ECM? The TCM will most likely have a U0100 (Lost Communication with ECM)

You have checked the fluid level, Engine running?

It has the Torque Converter bolts installed?

You have Battery power, Ignition power, & Ground at the Trans Plug?

If all that checks out, Pull the Trans cooler lines loose & place them in a 5 gallon bucket, Have someone start the engine, Their should be ATF coming out of one of the lines.

Do not spend money on having modules reflashed 'til you get this thing moving!

Did the "Junkyard" install the Trans to the engine?

**shadow1967** · 07-21-2015, 08:59 PM

Did the "Junkyard" install the Trans to the engine?

No we mated the two together with arp bolts and a quart or 2 in the torque converter

07-21-2015, 08:03 PM	#1
shadow1967 Senior Member Join Date: Jul 2011 Location: Hawthorne, CA Posts: 458	2008 ly6 w/6l90e I have a ly6 w/6l90e trans. Trans is out of a different truck than the engine. there was a problem with the pump so they sent a different trans with the engine. So my problem is engine runs great , ran it for 15 minutes and the heads never went above 217* So that's great, Now the BUT, it will not go into gear. Someone said The trans tcm needs to be reprogrammed as well. is this correct. Thanks in advance __________________ Build for my 1959 Fleetside... http://67-72chevytrucks.com/vboard/s...d.php?t=518308

07-21-2015, 08:51 PM	#2
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: 2008 ly6 w/6l90e Yes, If the Trans is not from the same vehicle as the ECM, The TCM & ECM will not Communicate with each other. The TCM will go into a Default/Limp mode, But the vehicle will still move, But will shift really weird. What codes are present in the TCM & ECM? The TCM will most likely have a U0100 (Lost Communication with ECM) You have checked the fluid level, Engine running? It has the Torque Converter bolts installed? You have Battery power, Ignition power, & Ground at the Trans Plug? If all that checks out, Pull the Trans cooler lines loose & place them in a 5 gallon bucket, Have someone start the engine, Their should be ATF coming out of one of the lines. Do not spend money on having modules reflashed 'til you get this thing moving! Did the "Junkyard" install the Trans to the engine?

07-21-2015, 08:59 PM	#3
shadow1967 Senior Member Join Date: Jul 2011 Location: Hawthorne, CA Posts: 458	Re: 2008 ly6 w/6l90e Did the "Junkyard" install the Trans to the engine? No we mated the two together with arp bolts and a quart or 2 in the torque converter __________________ Build for my 1959 Fleetside... http://67-72chevytrucks.com/vboard/s...d.php?t=518308



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