battery is good but car will not start. Check enging light is not on and when hooked up to auto scanner it will not scan
you need to wirebrush the battery cable at the point where it connects to the chassis ground...borrow a barbeque brush if you need to but coarse wirebrush it to expose the metal as every start will "Weld" the connection with great power of 300 amps and electrically fuse, leaving debris for an unreliable connection~....so disassemble the ground lug, wirebrush it clean...and the spot where it bolts to and tighten the bolt for a good ground connection...also the 1/0 cable that connects the engine to ground as this one also has to be able to put thru 300+ amps...Will heat the connections up and create corrosion...unfortunately~
clean the connections...if this isn't confusing the issue~
the positive side of things also has a 1/0 RED cable that goes to a starter solenoid...take a look at that connection and wirebrush that side too...if necessary~
are we on the same page? in the same building? on the same planet here?
Check for an ECM fuse. It may be blown. Since the PCM (Powertrain Control Module) won't communicate with the scan tool it sounds like the PCM is "dead". The check engine light should be on with the key in the run position but the engine not running. If not, this is another good indicator that the PCM isn't getting power. Some GMs have a single fuse hidden under the dash for this. HTH. -Jim
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