LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Geo >> 1993 >> Prizm Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Relays >> CIRCUIT OPENING RELAY (PRIZM LSi)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

CIRCUIT OPENING RELAY (PRIZM LSi)

  1. With ignition switch in ON position, momentarily backprobe PCM connector C1 from cavity A4 (M/T) or A14 (A/T) to ground. If fuel pump runs, measure voltage between DLC terminal FP and ground while cranking. If voltage is less than 10 volts, check for an open in Black wire between Clutch Pedal Position (CPP) switch/Park Neutral Position (PNP) switch and circuit opening relay or for an open in White/Black wire between circuit opening relay and ground. If circuit is okay, replace circuit opening relay and retest. If system remains inoperative, replace PCM.
  2. While backprobing PCM connector C1 from cavity A4 (M/T) or A14 (A/T) to ground, momentarily connect jumper from DLC terminal B+ to terminal FP if fuel pump does not run. See Figure . If fuel pump runs, remove jumper and backprobe circuit opening relay connector from cavity No. 2 to ground using a test light. If test light does not glow, repair open in Black/Red wire between fuse and relay box and circuit opening relay.
  3. If test light glows, turn ignition switch to LOCK position. Disconnect circuit opening relay connector. Connect a test light from circuit opening relay connector cavity No. 4 to B+. If light does not glow while cranking, check for open in Green/Red wire between circuit opening relay and PCM. If circuit is okay, replace PCM. If test light glows during cranking, check for an open in Blue/Black wire between circuit opening relay and fuel sender assembly. If circuit is okay, replace circuit opening relay.
NOTE: EFI main relay may be referred to as main relay.
scientia non olet · About LEMON Manuals