See attachments below on how to troubleshoot Coleman PWM modulating Valves.

IF you have the other version of this then you are looking for a mA signal.

From the UPG service guide " The gas valve is energized with 24 volts AC, measurable between pins 3 and 6 on the 6 pin plug connector. The modulation signal during ignition will be approximately 125mADC, which represents a 70% firing rate. "