Need help in Trouble shooting your 4.3L Vortec V6? Here is a site that will help you trouble shoot the items such as the ignition coil and the ICM/ Ignition Control Module . The site is: troubleshootmyvehicle.com and select GM 4.3L, 5.0L and 5.7L Vortec family. They all share the same Vortec components. The trouble shooting is done with a simple DVOM /digital volt ohm meter. No fancy scan tool required! Great info and you need to 'bookmark' it for future reference.