// Install guides
ROTARY SWITCH — 11-16 DURAMAX 6.6L LML
Never work on a hot vehicle. Let it cool before starting, and wear eye protection when working on or under it. By installing this product you assume all risk and liability for its use.
Wiring the rotary shift-on-the-fly switch into the ECM connector on a 2011–2016 Chevy/GMC 2500/3500 6.6L LML Duramax. Two pins in the connector nearest the firewall, then the switch through the firewall into the cab. Kit GDP410017: A. Loomed electrical wires B. Dial stickers C. Switch control board D. Switch knob E. Allen wrench
Steps
1 Unplug the ECM connector closest to the firewall
2 Route the connector out through the wheel well and open it
Remove the plastic top cover and the pin retainer.
3 Feed the switch harness through the firewall and open pins 11 and 35
Push the plastic plugs out of pins 11 and 35 from the top side down.
2011 trucks sometimes have a yellow wire already in pin 11. It is fine to remove it, or to piggyback the SOTF wire onto it.
4 Insert the purple wire into pin 11 and the ground wire into pin 35
5 Reassemble the connector and plug it back in
Refit the top cover and the bottom retainer. Zip-tie the switch loom to the ECM harness, feed the harness back through the fender into position, and reconnect it to the ECM. Make sure the locking lever cams fully over, then slide the red lock tab across to re-engage the lock.
6 Check the switch pin position
The pin on the switch control board should sit between the 5th and 6th slot, as pictured.
7 Troubleshooting
To confirm the switch is working, use EFI Live or similar software and watch the fuel temperature sensor. It should change by 10°C for every level:
Level 1: 10°C
Level 2: 20°C
Level 3: 30°C
Level 4: 40°C
Level 5: 50°C