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P1780: Transmission Control Switch Circuit, Overdrive Off Switch Not Cycled During The Self Test

MAZDA MERCEDES NISSAN CADILLAC CHEVY GM GMC BUICK
Severity
Medium
System
Manufacturer-Specific Powertrain
Last reviewed: Last updated:

Methodology: We combine code standards with complaint and reliability patterns, then review for clear, vehicle-first diagnosis steps.

Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).

Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.

What Does P1780 Mean?

P1780 is a manufacturer-specific diagnostic trouble code: Transmission Control Switch Circuit, Overdrive Off Switch Not Cycled During The Self Test. This code applies to MAZDA, MERCEDES, NISSAN, CADILLAC, CHEVY vehicles. Unlike generic OBD-II codes, manufacturer-specific codes are defined by the vehicle maker and may only apply to certain makes and models.

Symptoms of P1780

Common Causes

Frequently Asked Questions

What does P1780 mean?
P1780 indicates: Transmission Control Switch Circuit, Overdrive Off Switch Not Cycled During The Self Test. The vehicle's computer has detected that the Transmission Control Switch is not operating within its expected parameters and stored this diagnostic trouble code.
Can I drive with code P1780?
You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P1780 for extended periods may cause additional problems.
How much does it cost to fix P1780?
Repair costs for P1780 typically range from $80 to $300, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

  • 🔧 Inspect and repair Transmission Control Switch wiring and connectors
  • 🔧 Replace faulty Transmission Control Switch
  1. 1
    Find your vehicle above

    Click your make and model for real owner reports and common causes specific to your vehicle.

  2. 2
    Check for recalls

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.

  3. 3
    Get a professional diagnosis

    A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

Related Codes

P1700 Transmission Indeterminate Failure (Failed to Neutral) P1701 Transmission Range Sensor Reverse Engagement Error P1702 Transmission Range Sensor Circuit Intermittent P1703 Low Clutch Timing Control Solenoid Valve Circuit Malfunction P1704 Digital TRS Failed to Transition States in KOEO / KOER P1705 2-4 Brake Pressure Solenoid Valve Solenoid D Circuit P1706 TCM A/T Gear Position Switch Circuit Open P1707 Transfer Case Neutral Indicator Hard Fault Present P1708 Clutch Switch Circuit Malfunction P1709 Park or Neutral Position Switch Out of Self-Test Range