Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSSATURN1992SL1 AUTOMATICREPAIR AND DIAGNOSISENGINE PERFORMANCESYSTEMENGINE CONTROLS - TESTS W/CODES - 1.9L TBIPCM/BCM CODE CHARTSCODE 42: BY-PASS OPEN OR SHORTED

1992 Saturn SL1 Automatic

Code 42: By-Pass Open Or Shorted

1992 Saturn SL1 AutomaticSECTION Code 42: By-Pass Open Or Shorted

PCM has an internal feedback to monitor state of by-pass circuit. Code 42 will set if by-pass circuit is open or shorted to ground at time of engine start-up. If Code 41 is set with Code 42, use CODES 41 & 42 SIMULTANEOUS chart.

Fig 1: Code 42, Schematic, By-Pass Open Or Shorted

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

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.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.