Attention: TDR Forum Junkies 
I have a '93 in the driveway and I'm trying to help a friend with what seems like an electrical gremlin (even chevy gave up). After the car has been allowed to get hot, and some restarts are done, the security light (far left of cluster) and the digital display show "SYS" instead of any reading. When this happens, The engine will only crank and it won't fire. I am getting fuel pressure and voltage to the ECM at all pins where my schematic shows it should be (rule out bad connections or IGN switch). I pinned out the grounds too, and all look OK.
If a cool down is allowed, it will refire and run OK.
Some men before me seemed to be zeroing in on the security system, and GM replaced the CCM, and according to the TECH2 I used, all is well with that as far as I can see- it even works!
Is there an engine protection system that might be shutting the engine down? What does the "SYS" mean on the digi display?
Any help is appreciated.
If a cool down is allowed, it will refire and run OK.
Some men before me seemed to be zeroing in on the security system, and GM replaced the CCM, and according to the TECH2 I used, all is well with that as far as I can see- it even works!
Is there an engine protection system that might be shutting the engine down? What does the "SYS" mean on the digi display?
Any help is appreciated.
