How to Remove a Nissan Titan ECUby Alibaster Smith
The ECU in a Nissan Titan controls everything from the air/fuel mixture to idle speed. The ECU is the "brain" of the car, and the vehicle wouldn't run without it. If you need to replace the ECU in your Nissan Titan, you can do it yourself. The job should take about 45 minutes the first time you do it.
Open the hood and disconnect the negative cable from the negative terminal on the battery. Unhook the positive cable from the positive terminal on the battery.
Unbolt the battery tie down rods and remove the battery and the battery holder. The battery holder just sits under the battery and should not be fastened down.
Remove the fuse box next to the battery compartment. It's held in place with clips.
Remove the second box, which is held in place with several bolts, to gain access to the lower 10 mm bolt below that.
Unbolt the lower 10 mm bolt and carefully remove the ECU, which is held in place with retainer clamps. If you break these clamps, you will need to buy a new ECU, so be careful when removing it.