Test SC-3A - Checking Speed Control Set/Resume Switch

1992 GMC Value Van 4.3 Z, AutomaticSECTION Test SC-3A - Checking Speed Control Set/Resume Switch
WARNING: This page is about a different car, the 1995 Dodge Ram Wagon and 1995 Dodge Ram Van. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Speed control switch connector must be connected to perform the following step.
  1. With DRB in voltmeter mode, backprobe speed control switch connector terminal No. 4, speed control coast/set switch sense circuit (Brown/Red wire). If voltage is less than 10 volts, replace speed control switch. Perform VERIFICATION TEST SC-VER  .
  2. If voltage is greater than 10 volts, while observing DRB, press speed control set switch. If voltage is greater than one volt with set switch pressed, replace speed control switch. Perform VERIFICATION TEST SC-VER  . If voltage is less than one volt with set switch pressed, turn ignition off.
  3. Disconnect Powertrain Control Module (PCM) 60-pin connector. Check connector for damaged, pushed out or miswired terminals. Repair as necessary. Perform VERIFICATION TEST SC-VER  . If connector is okay, turn ignition on. With DRB in voltmeter mode, probe PCM connector terminal No. 48, speed control coast/set switch sense circuit (Brown/Red wire).
  4. If voltage is greater than 10 volts, replace PCM. Perform VERIFICATION TEST SC-VER  . If voltage is less than 10 volts, repair open in Brown/Red wire. Perform VERIFICATION TEST SC-VER  .
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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
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