1994 Dodge Ram "Battery connection to PCM"

1994 DODGE RAM
150,000 MILES • V8 • 2WD • AUTOMATIC
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CELTICWOODS
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  • 1 POST
Got an error code of 12 "Problem with the battery connection. Direct battery input to PCM disconnected within last 50 ignition key-on cycles" Occasionally the truck would just not fire, like it was getting no fuel, this last time I was showing no fire from the coil so I replaced that along with the cap and rotor. I checked voltage at the coil wire harness, and got 13 volts when set to a body ground, but only got 5 volts when grounded to the harness. How do I check the battery connection to the PCM, or anything else I might need to check?
Oct 25, 2009 at 12:36 PM
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JDL
  • ✓ASE Certified Mechanic
  • 16,098 POSTS
  • ASE Certified Mechanic
I'd make sure battery and connections are good. If it ever cranks good but won't start but has no spark at plugs, The dark green wire with orange tracer carries primary voltage to the coil--injectors--02 heater circuit. That voltage comes from asd relay. If that the pcm doesn't ground that relay check crank and cam signal. Fuse link 8--20 amp, underhood fuse box, carries battery voltage to pcm.
Oct 25, 2009 at 1:10 PM
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