LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> GMC >> 1998 >> Forward Control 5.7 R, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> Testing & Diagnosis >> Engine Controls - System & Component Testing - 5.7L >> Computerized Engine Controls >> Control Unit >> Ground Circuits
September 30: LEMON manuals is back up on a temporary server! Slowness is possible

Ground Circuits

  1. Using an ohmmeter, check for continuity to ground on PCM/VCM ground terminals. See POWERTRAIN CONTROL MODULE (PCM)  table. Resistance should be zero ohms. If not, repair open to ground.
  2. Connect negative lead of a voltmeter to a good ground. Backprobe positive lead of voltmeter to each ground terminal. With vehicle running, voltmeter should indicate less than one volt. If voltmeter reading is more than one volt, check for open, short to voltage, corrosion or loose connection on ground circuit.