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Home >> Geo >> 1994 >> Prizm Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Diagnostic Code Charts (PRIZM) >> Code 12 (PRIZM) - No Rpm Signal >> Diagnostic Aids

Diagnostic Aids

Check for cracks in distributor cap and rotor. Check for properly adjusted signal rotor air gap. An intermittent condition may be caused by poor connection, rubbed-through insulation, or a broken wire inside insulation. Check ECM harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connections before component replacement.

Fig 1: CODE 12 - Schematic (Prizm) No RPM Signal
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Fig 2: CODE 12 - Flow Chart (Prizm) No RPM Signal
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