99 gmc jimmy no spark, no fuel pump
Got a 99 jimmy that won't start, it has no spark at the coil,
and the fuel pump doesn't engage. Swapped out the ecm,
the coil, ignition control module, the crankshaft piston
sensor, and cleaned all the ground to the frame, motor,
and body, checked all the relays, and changed the ignition
switch. Any ideas?
Battery has a full charge and connections all good? As far as no spark, did you check primary voltage at ignition coil, pink wire, goes hot with key on and fuse protected. Note the diagram. Does the dis rotor turn when you crank it? Any applicable trouble codes?
The distributor does turn, and I can pull codes, says there is a communication error that started at the same time as the no start issue, checked all fuses and swapped all relays with ones from a parts Jimmy. I'll check the primary wire
I can't pull codes
I do have voltage at the coil with the key on
At the coil terminal will test light pulse when you crank it? If so, hopefully that means the module is switching the ground. If you can't communicate with computer, that's a problem. Is computer functional? You checked computer voltage and ground circuits? One way to tell if computer is awake, check ref voltage at any sensor that uses a ref voltage, key on. If you have ref voltage, computer is awake. If no ref voltage, something wrong with computer or wiring circuits. My opinion.
No pulsating current at the coil terminal. Checked the air temperature sensor, had voltage with key on ( .4 volts about ) as well as at the mass airflow sensor.
What are the red and blue wires going into the intake mine will start sometimes when I mess with those wires but dies out
