Keep a laminated copy of the pin legend next to your workbench, invest in a decent multimeter, and remember: The diagram never lies—only the corroded connector hiding in the engine valley does.
Find pin A27 (labeled Terminal 15 – Ignition). Use a multimeter: Should read 12V with key ON. If not, the main relay or fuse is dead. bosch ecu wiring diagram
Drop the hardware number in the comments for pinout suggestions. Keep a laminated copy of the pin legend
Find the CKP sensor pins A48 and A49 . Set your multimeter to AC voltage. While cranking, you should see between 1.5V and 3.0V AC. If you see 0V, the sensor or wiring is broken. invest in a decent multimeter