// Install guides
ROTARY SWITCH — 06-10 DURAMAX 6.6L LBZ/LMM
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 on a 2006–2010 Chevy/GMC 2500/3500 6.6L LBZ or LMM Duramax. Two pins in the larger ECM plug, then the switch through to the cab. Kit GDP410016: A. Loomed electrical wires B. Dial stickers C. Switch control board D. Switch knob E. Allen wrench
Steps
1 Locate the ECM plug
2 Remove the larger plug
It is connector 1 of the two on the ECM.
3 Remove the purple locking clip
Do not lose it.
4 Remove the top cover
5 Insert the new pins
Signal, the purple wire, goes into pin 46 of the larger plug. It sits next to the grey wire on an LBZ and next to the tan wire on an LMM.
Ground, the black wire, goes into pin 54 of the larger plug, next to the yellow/black wire.
Then reverse the removal steps: refit the top cover and the purple locking clip, and plug the connector back into the ECM.
6 Pin-out reference
Viewed looking at the connector face. The diagram shows the signal and ground positions.
7 Check the switch pin position
The pin on the switch control board should sit between the 5th and 6th slot, as pictured.
8 Troubleshooting
You need a voltmeter. Set the switch to position 1 and turn the key to Run, engine off or on. Test the switch-on-the-fly wire, the purple one. The reading varies a little within each level (4.0–4.9 in position 1, for example) but should be close to:
Level 1: 4.5 V
Level 2: 3.5 V
Level 3: 2.5 V
Level 4: 1.5 V
Level 5: 0.5 V
High idle: 5.0 V
If the readings do not match, check the connections and pins for anything bent or broken, and make sure no debris is stopping a pin seating fully. If it persists, call tech support on 877-223-5018.