This article will explain how to install your LBZ / LMM DSP5 switch.
1. Open your hood and locate your ECM.
ECM can be found near the battery located at the front driver side of the engine compartment.
Make sure you do not remove the TCM unit marked Allison on the driver side fan shroud.
2. Disconnect the ECM connectors from the ECM.
3. Locate the hood release grommet found on the driver side firewall.
It is a small rubber grommet located roughly 6 inches down from the hood at the firewall and 4 inches to the left of the driver side fender.
4. Pull the grommet out.
5. Run your guidewire through the hole into the cab and locate the guidewire under the dashboard.
6. Use electrical tape to secure the DSP5 wires to the guidewire.
7. Carefully pull the guidewire through the hood latch hole into the engine compartment. Make sure that you have enough wire on the engine compartment side to run the wires into the ECM harness.
8. Use the conduit provided with your DSP5 switch to protect the switch wires from heat.
9. Carefully put the hood latch grommet back in place around the DSP wires.
It helps to make a small cut in the grommet for the wires to run through.
10. Now locate the larger connector on the ECM harness and make sure that it is in the closed position. With a small screwdriver remove the cover on the ECM harness.
11. Remove the purple slide that is holding the existing pins into the ECM harness.
12. Locate the pinholes that the switch pins will go into. Pinhole #46 and pinhole #54.
13. Push the DSP5 switch pins into the correct holes. Be sure that you push them in all the way to the bottom of the ECM connector.
14. Reinsert the purple slide into the ECM harness.
15. Reconnect the cover of the ECM harness.
16. Reconnect the ECM connectors to the ECM. Make sure you attach the larger connector to the ECM first followed by the smaller connector.
To Test/Verify switch install
Once your DSP5 switch is installed and the tune is flashed onto your truck follow these steps the test/check the installation of your switch.
- With your spade device hooked up to the truck and the key in the on/run position, select Scan Tool from the menu on your spade device.
- Then click Select PIDs.
- Scroll down and select the correct PID list for your truck. (06-07.5 - LBZ, 07.5-10 - LMM)
- Then select Display Data.
- Scroll through that list until you find the PID E35_DSP5.
- Once you have found that PID, as you move the switch the value for that PID should change, if it does not the switch may not be installed in the correct pin positions or the pins may not be seated in the ECM connector all the way.
If you are still having issues go to the DSP5 Switch Trouble Shooting section.