1998 Chevrolet K3500 454 vortec has no spark

I forgot to mention also that there is no codes when hooked to a reader.

Crank engine and check for RPMs. If no rpms are present, your tachometer circuit has an open. If there is an open in this circuit, the coil will not fire. First check your fuses. Next, turn key on to accessory and check for 12VDC at Pin A (pink wire circuit 439) at the Ignition Control Module, and Pin A at the (Pink wire circuit 439) at the Coil. If both have 12VDC go to the next step. Next, with key on, at the coil there is a white/black wire at Pin C (this is circuit 1841). Check for trigger signal from the coil at pin C (circuit 1841) to pin D of the ignition control module. Reconnect the connectors and you will need to backprobe the wires at the respective pins through the back of the both wiring plugs of both ICM and Coil wiring plugs. The back of the wiring plugs have a rubber coating surrounding 3 wires. With them plugged in, attach the clamp lead of a test light to the Positve battery terminal and push the probe end of the test light down along the wiring to reach pin C of the coil and check for a flashing 12VDC trigger signal while cranking the engine. If there is no flash present from the test light you will need to repair the tachometer circuit. Note: Again there will be 12VDC at the coil from the pink wire (circuit 439) Pin A, but the coil will not fire unless the Tachometer is reading RPMs.. Once circuit 1841 is repaired ( that is, from pin D of ICM to pin C of Coil) . There is a white wire (lead 121) from the ignition coil to the instrument cluster. This is the tachometer input signal circuit. If there is no voltage between circuit 1841 (Pin D of the ICM and pin C of Coil) with the engine cranking, you will need to cut the white wire at the coil (lead 121) (make sure to leave enough wire, an inch or more from the connector to rewire the circuit) from pin B of the coil, to the back of the Tachometer at Pin 6 to repair this circuit. The (121) circuit acts as a continued part of circuit (1841) This is the entire Tachometer circuit. On the diagram lead 439 and all branches should have 12VDC when the key is turned on. Once the Tachometer circuit is repaired the coil should fire.

Correction on Circuit 1841. The picture is blurry. Upon closer inspection It is actually circuit 1847, all other information is correct. Sorry about the mixup. Hope this helps.

Thank you for the response, The pickup is registering RPMs, I am getting a 12V reading on each of the wires. There is an pink/white wire that comes from the PCM to the ICM which is apparently the switching signal wire, this wire is getting no power during cranking.

Do a continuity check on the circuit from 423 which is the ICM to PCM circuit. Some wiring colors may vary, however check for an open on circuit 423. If no continuity is found, repair the circuit and then attempt to crank and observe coil wire for spark. If all other circuits have proper voltage standing by with the key on and there is continuity between ICM and PCM check all vehicle grounds there should be 3 on the engine. One on the block to the chassis (grounding strap) on passenger side near starter. One near the alternator to frame and vehicle battery ground to carriage. Ensuring that all circuits are repaired and grounds are good. Ensure oil pressure sending unit is displaying a signal on the instrument cluster. Given everything repaired though, at this point have you considered replacing the Crankshaft Positioning Sensor and Camshaft Positioning sensor on the distributor? Both must have good correlation to ensure PCM signal input/output. If everything else is good have you considered replacing the PCM?

Crankshaft sensor