Final Control Module Or Ignition Coil Check

If ignition coil is suspected of being defective, substitute a known good coil and attempt to start vehicle. If it starts, reinstall old coil and start vehicle. If it then fails to start, replace with new coil. If control module is suspected, substitute a known good module and start vehicle. If it starts, reinstall original module. If vehicle fails to start now, install new control module. If system still fails to operate, disconnect tachometer connector at instrument cluster. Attempt to start engine. If engine now starts, replace tachometer.