LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Geo >> 1995 >> Prizm Base, Standard >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (Engine Controls - Tests W/Codes - 1.8L) >> DTC Charts >> DTC 27 (Federal Emissions) Sub-O2 Sensor (Sub-O2S), Open Or Shorted Circuit >> Diagnostic Procedures
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedures

WARNING: This page is about a different variant/trim than selected.

Verify clean, tight connection on G106 (Brown wire). An intermittent condition may be caused by poor connection, rubbed-through insulation, or a broken wire inside insulation. Check PCM 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: DTC 27 Schematic (Prizm 1.8L - VIN 8) (Federal Emissions) Sub-O2 Sensor (Sub-O2s), Open Or Shorted Circuit
G95A31807
Fig 2: DTC 27 Diagnostic Flow Chart (Prizm 1.8L - VIN 8) (Federal Emissions) Sub-O2 Sensor (Sub-O2s), Open Or Shorted Circuit
G95E31769