// Install guides
EFI LIVE FUSES — 01-10 DURAMAX 6.6L
LB7 (2001–2004) and LLY (2004.5–2005) controllers use a communications platform that is not robust and was replaced in 2006. These controllers often fail with factory tools and can be left unrecoverable. Follow the tips below before flashing one. If a full flash fails, do not remove power from the controller. As long as it stays powered, EFI Live's boot loader keeps waiting for a successful full flash.
Which fuses to pull before flashing an EFI Live tune on a 2001–2010 Chevy/GMC 2500/3500 Duramax, with tips for the LB7 and LLY controllers, whose communications are fragile, and what to do if a flash fails.
Steps
1 2001–2002 Duramax: pull fuses SEO IGN, RDO1 and RAP2
Once the download is complete, reinstall all fuses.
2 2003–2005 Duramax: pull fuses TBC BATT, TBC IGN1, RADIO and INFO
Once the download is complete, reinstall all fuses.
3 LB7 and LLY: use a bench harness for reading and flashing
Recommended. It takes the truck's data bus out of the picture entirely.
4 LB7 and LLY: remove or isolate every aftermarket device
Mobile phone adapters, audio systems, security, remote start and anything wired into the OBD port.
5 LB7 and LLY: do not operate anything that talks on the data bus
That includes opening or closing the hood, doors or windows, changing settings on the radio or HVAC, and connecting or removing charging devices.
6 LB7 and LLY: check available licenses
The first time FlashScan or AutoCal flashes a controller, licensing requirements are validated and must be met for the flash to succeed. See EFI Live's License Status knowledgebase article.
7 LB7 and LLY: look up any EFI Live error code
The code shown on FlashScan or AutoCal and in the EFI Live software is the main diagnostic tool. Look the number up in the EFI Live error code list for the cause and suggested solutions.
8 If flashing still fails, isolate fuses
Communication problems are commonly reported with the ABS, BCM, Radio, Info and Lift Pump fuses.
9 If flashing still fails, drop to low speed flashing
If you were flashing in high speed, revert to low speed.
10 If flashing still fails, use pass-thru rather than standalone
Read and flash pass-thru from the PC instead of standalone on the device.
11 Recovering a failed full flash on LB7 or LLY
Power still on the controller: retry the full flash until it succeeds. EFI Live's boot loader running in the controller keeps waiting for one as long as power is never removed.
Power was removed: the controller may only be recovered if the flash was at least 15–20% complete and the communications codes had been reprogrammed to let it run in dead poll mode. Retry the full flash.
If flashing then fails with a "no communications" error, the controller has probably been rendered inoperable and unrecoverable. The only way back is to disassemble it and physically remove, reprogram and replace the flash chip on the main circuit board.
12 Recovering a failed calibration-only flash
A calibration-only failure is not critical and generally does not leave the controller unrecoverable. Turn the ignition off, wait 30 seconds, turn it back on, wait a further 10 seconds, then retry the calibration-only flash.
If it keeps failing: remove battery power from the controller, either by pulling the controller's fuse or disconnecting the battery, wait 30 seconds, reconnect power and retry.