G 1500 1/2 Ton Van V8-305 5.0L VIN H 4-bbl (1984)
Ignition Control Module: Testing and Inspection
If the vehicle cranks for at least 5 seconds and the Engine Control Module doesn't see a referance signal, some Models will set a code, 42 (Hard) or 12
(Soft). If your vehicle has one of these codes, begin with the Diagnostic System Check in Computers and Controls, then proceed to the Trouble Code
Chart (Yes, some vehicles have a DTC Chart for Code 12).
If the vehicle does not set a code, begin with the Diagnostic System Check, and it will send you to a Diagnostic Chart that checks for your particular
condition.
These types of tests are found under Computers and Control Systems. See: Computers and Control Systems/Testing and Inspection