hello i have a 93 blazer with 4.3 vortec with vin code w. it well start and run fine for a few minutes then sputter and die wait a second and it well start right back up run for a few and die. i pulled the codes and it was throwing a code 42 for ignition module pulled it and went and had it checked (8 times in a row) checked out fine. im stumped any ideas as to what it could be? any help is greatly appreciated.

 

DTC 42 = The EST signal did not change when the ECM applied bypass voltage to the ignition module.

It means the PCM has seen an open or short to ground in the ICM or bypass circuits.

Check the wires that connect to the ICM for cracked/peeled/melted insulation. Check the connectors themselves - any melting or arcing visible?

 

got it fixed faulty ECM i guess got a new one fixed the problem even though the old one checked out good somethin the tester ta the parts store didnt pick up on