Is there anyway to check the VCM-A
DelCoch
08-07-2006, 03:46 AM
Is there anyway to check the VCM-A on a 95 Jimmy 4.3 that won't start? (It has the enhanced ignition system with the plug wires on top of the distributor, there is no module inside the distributor)
There is 12V going into the VCM, 12V going into the coil, 12V going into the crankshaft sensor, and all have a good ground.
The 1-4 volts to the coil driver module from the VCM is not there. Thus, no spark from the coil, and no spark to the plugs.
Also, while cranking there is no return voltage from the crankshaft sensor, which was replaced new and still no return voltage when cranking. Should there be voltage from the crankcase sensor while cranking or only when the engine is running??
It appears the VCM might be bad, but I would like to know for sure before laying out the big bucks for a new one.
Any and all suggestions will be more than welcome!!
There is 12V going into the VCM, 12V going into the coil, 12V going into the crankshaft sensor, and all have a good ground.
The 1-4 volts to the coil driver module from the VCM is not there. Thus, no spark from the coil, and no spark to the plugs.
Also, while cranking there is no return voltage from the crankshaft sensor, which was replaced new and still no return voltage when cranking. Should there be voltage from the crankcase sensor while cranking or only when the engine is running??
It appears the VCM might be bad, but I would like to know for sure before laying out the big bucks for a new one.
Any and all suggestions will be more than welcome!!
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