SC024_010: PWM output of C2P12 Stops during operation.

[G.Hillier]

I am using PWM output of C2P12 on a SC024_010 Controller to control a throttle actuator on a small diesel engine.  On power up the motor successfully does a "self check" by moving from low throttle to full throttle and back to low.  Upon starting the engine the rpm approaches its initial set point for warmup but will freeze after approximately 5 seconds of travel.  The output of the Controller_PID and PWM_Driver functions indicate that the actuator should be moving but there is no measurable output on C2P12.  If I lower the set point below the current rpm (to reverse direction of the motor)  the output of the function blocks changes as expected but there is still no output on C2P12.

Can anyone shed some light on what may be causing this?  Thanks.

Edit:  March 11, 2014
Problem solved.  The wire on the adjacent pin had frayed and was touching the C2P12 terminal.  When the engine was started this output was activated and caused C2P12 to stop functioning.

[dlewis]

I had a similar problem once.  With the truck key on, but the engine off, everything seemed to operate fine.  As soon as the engine was started the valve would not operate.  I was using a MC050-010 controller with a PVG32 valve.  And to top it off I had several trucks before this one that would operate without any problems.  What I found is that pins that I had used to power the PVG32 valve could not handle the inrush current when the truck was running.  With the engine off, the voltage was around 24-25 volts, but with the truck running the voltage was 27-28 volts.  The extra current with the engine running was enough to cause the output pin to shut itself down.  You may be experiencing something similar.