2006 Lexus GX470 - Struck by lightning.

The customer had the vehicle towed into the dealership, stating that the vehicle had been struck by lightning while driving it. The customer also stated that it just died and would not restart. After doing some inspection of the exterior, we determined that it had been in contact with lightning. The right rear wheel had carbon tracks on the tire and three little spikes on the rim lip.

Next I tried retrieving codes. I was not able to communicate with any of the modules.

Now what? Time to test the CAM BUS.

This Lexus uses two 120 ohm resistors to terminate the CAM bus. I measured the CAM BUS and it was 60 ohms like the specs stated. But there is another step to this, you need to check for a short to ground or a battery source.  Bingo, we have a short to power.  This vehicle has a junction block that all the connection for CAM bus.  This junction block makes it pretty easy to determine the culprit. After removing the radio to access the junction block, I was able to determining that the STEERING ANGLE sensor was shorted.

Now let’s check for communication. I can now see the ABS and YAW sensor, but still no ECM.

Next step is to perform a pin check on the ECM connectors. That checked out good, so the the ECM will need replacement in order to continue diagnosis.