It's not as hard as you think LT. I used to be scared of them but actually find it kind of nice now. If a code is set and the CEL is on 90% of the time it's electriical and 10% mechanical. If no light then it's usually mechanical. Troubleshooting is mostly as it's always been, test light and multimeter, check for power where your supposed to have it, ground where your supposed to have it, and correct voltage as needed. Occasionally you'll have to check for resistance and on rare instances trying to narrow down a problem use the live data logging from your code reader