APCM working with no rpm change

[scott1984]

95/96 model year super duty with APCM not working correctly. knowlegde is needed, it turns on and works fine but there is not rpm change it stays at 650-700rpms.

[DwayneGorniak]

Are all the requirements for activation met? Park brake indicator coming on when park brake is applied? Is the neutral safety switch actually reading park in park or neutral if it is a standard? And are there any dtc's in the PCM?

[scott1984]

well the e-brake is mess up at the drum on trans for about 6 months. but was working okay and just quit last week been working fine the only dtc is p1111 system pass. i do not know about neutral safety switch but if it was messed up the truck would not start correctly right i don't know never messed with one before

[kridd12]

I have seen a few times the wires break at the back of the apcm where the wires go back up under the dash. Had one about a month ago do this. can't remember off the top of my head which wires they were but the thing read rpm and lit up but could not change rpm. Have also seen bad apcm's as well.