the module is under the coils, unplug the wires, unbot all three coils and unbolt the module. Make sure to use plenty of dielectric grease for a good ground
I need to change mine really soon.
Code 42 is the ignition module faulty or loose connections.
Begin by removing the wiring harness from your 1998 Chevrolet Suburban ignition module. Remove the ignition module retaining screws. Reverse the process to install your new ignition module.
How do you change the ignition control module in a 1988 Chevy Silverado 5.7L
Ignition module. See if spark plug wires have arched. Check for spark. You could change it yourself. Module plus new wires will cost you around $200.
All together depending on where you go parts and labor about 722.00 : - )
If you have disributorless ignition it will be mounted under the coil pack . If you vehicle still has a distributor it will be in the dist.
Check your fuses
Remove the wiring harness from your 1995 Chevy Blazer ignition control module. Remove the ignition control module retaining screws. Reverse the process to install your new ignition control module.
Disconnect the battery. Remove the ignition coils. Remove the ignition control module that was under the coils, and replace it.
there is no ignition control module on the 1996 model its all through the PCM
Bad coils or perhaps a bad crankshaft position sensor.
3 possibilities, camshaft sensor, ignition module, sparkplugs