P1780 on Toyota
Transmission Control Switch (O/D Cancel) Circuit Out of Self-Test Range
P1780 on Toyota vehicles indicates transmission control switch (o/d cancel) circuit out of self-test range. Au7o has documented this code across 1 Toyota model — most commonly on Corolla. This manufacturer-specific code (Ford, Lincoln, Mazda, Mercury) means the computer did not see the expected change of state from the Transmission Control Switch (the Overdrive Off / O-D Cancel or Tow-Haul button) during its self-test. That switch tells the transmission whether to allow overdrive, and if its signal is stuck or the wiring is faulty, the PCM/TCM flags it. You may notice the overdrive light flashing or the transmission not engaging or canceling overdrive properly. It is usually a switch or wiring problem rather than internal transmission damage. Typical repair costs on Toyota range from $600 to $1,400, depending on the specific model and root cause.
Common Causes of P1780
- •Faulty or stuck overdrive/transmission control switch
- •Damaged or corroded wiring at the switch or transmission connector
- •Loose or corroded transmission range connector pins
- •Open or shorted switch circuit
- •Moisture intrusion at the connector
- •Faulty PCM/TCM input (less common)
P1780 on Toyota by Model
Toyota Corolla(1 issue)
- ECM/PCM Failure Causing Harsh Shifting, No-Start, and MIL Illumination2000-2004
Early-2000s Corolla models are well documented for engine control module failure caused by defective internal circuitry and capacitor/board degradation. Owners report harsh or erratic automatic transmission shifting, stalling, no-start conditions, and check-engine lights because the ECM also controls transmission logic on these cars. Toyota issued a warranty enhancement and service campaign for many affected vehicles, making this one of the best-documented Corolla problems of the period.
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View P1780 across all makes →Frequently Asked Questions
What does P1780 mean on Toyota?▼
P1780 stands for "Transmission Control Switch (O/D Cancel) Circuit Out of Self-Test Range." This manufacturer-specific code (Ford, Lincoln, Mazda, Mercury) means the computer did not see the expected change of state from the Transmission Control Switch (the Overdrive Off / O-D Cancel or Tow-Haul button) during its self-test. That switch tells the transmission whether to allow overdrive, and if its signal is stuck or the wiring is faulty, the PCM/TCM flags it. You may notice the overdrive light flashing or the transmission not engaging or canceling overdrive properly. It is usually a switch or wiring problem rather than internal transmission damage. On Toyota specifically, this code is documented across 1 model.
What causes P1780 on Toyota vehicles?▼
Common causes on Toyota: Faulty or stuck overdrive/transmission control switch, Damaged or corroded wiring at the switch or transmission connector, Loose or corroded transmission range connector pins, Open or shorted switch circuit, Moisture intrusion at the connector. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P1780 on a Toyota?▼
Repair costs on Toyota range from $600 to $1,400, depending on the specific model and root cause.
Which Toyota models have P1780 documented?▼
Au7o has documented P1780 on 1 Toyota model: Corolla.