96 gmc jimmy no start

1996 gmc jimmy wont start,has no spark,replaced control moduel,no change,please advise. thankyou.

The ignition module on a '96 is controlled by the PCM. The PCM requires a signal from the crank position sensor to operate the ignition module. It also needs a signal from the cam position sensor to correctly phase (time) the ignition module.

I used a OBD2 scaner and it showed no trouble codes? please advise,thankyou.