P077A

Output Shaft Speed Sensor Circuit - Loss of Direction Signal

OBD-II diagnostic trouble code P077Aindicates a fault detected by the vehicle's onboard computer. This code applies to all OBD-II compliant vehicles and should be addressed promptly to avoid potential engine or emissions system damage.

Severity Level 4 — Serious

This code indicates a serious issue that can cause noticeable driveability problems and potential engine damage if not addressed. The vehicle should be taken to a mechanic as soon as possible. Extended driving is not recommended.

Common Symptoms

• Check engine light on
• Reduced fuel economy
• Possible rough idle or hesitation

Possible Causes

• Output Shaft Speed Sensor Circuit - Loss of Direction Signal
• Manufacturer-specific condition
• Fault in related component or circuit

Common Fixes

• Diagnose with professional OBD2 scan tool
• Check manufacturer TSBs
• Inspect related components per service manual

Estimated Repair Cost

These are estimated costs based on generic repair data. Actual costs may vary depending on your vehicle, location, and labor rates.

Explore Repair Costs

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