03 trailblazer, crank but no spark. There is no power going to the crank sensor, VVT sensor, & the lower voltage wire to all the coil packs has no power, the coil packs are getting the 12volts though. Checked fuses & relays, replaced throttle body, replaced crank & cam sensor, replaced ignition switch. Oh, the cam sensor does have power. What could be the issue? Stored codes were 0014,. 0128, 0171, 0440, 0442,

 

P0014 Exhaust Camshaft Position Timing - Over-Advanced (Bank 1)
P0128 Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temperature)
P0171 System Too Lean (Bank 1)
P0440 Evaporative Emission Control System Malfunction
P0442 Evaporative Emission Control System leak Detected (small leak)

I don't think these issues would prevent your motor from starting up. Might be a bad ECM.

 

Ya I didn't think those codes were related to no spark either. I'm thinking PCM also. The window does say it has an aftermarket alarm, wondering if that could be the culprit. I bought it off a guy who couldn't get it to start again, couldn't figure it out.

 

So with this 03 trailblazer, I replaced the PCM with new & still no spark. I noticed when I teat the two yellow & purple crank sensor wires with a logic probe the fuel system pressurized each time I touched bare wire.... why would that happen?