Having a Mazda vehicle with the code P1780 can be a concerning issue. The code P1780 stands for Transmission Control Switch Circuit Malfunction (Self-Test) and is triggered when the engine is running and the PCM detects the Transmission Control switch signal does not change its status in the CCM test. The cause behind this can be various malfunctions, such as faulty wiring, a broken TCS switch, or even a PCM failure. Knowing the causes and solutions for this code can help solve the issue quickly and efficiently. Below is a table with a list of causes and solutions for the Mazda Code P1780.
Mazda Code P1780 Causes and Solutions
| Cause | Solution |
|---|---|
| TCS switch not cycled at the proper time in the KOER Self-Test | Check the TCS switch for any apparent defects, and replace it if necessary. |
| TCS switch signal circuit is open or shorted to ground | Inspect the wiring and ensure that the TCS switch signal circuit is connected correctly and not damaged. |
| TCS switch signal circuit is shorted to VREF or system power | Check if VREF and system power are functioning correctly, and test the TCS switch signal circuit. |
| TCS switch is damaged, out-of-adjustment, or has failed | Replace the faulty TCS switch if necessary, or adjust it to the proper setting. |
| PCM has failed | Replace the PCM with a new one. |
TCS Switch Not Cycled
The first cause of Mazda Code P1780 is when the TCS switch is not cycled at the proper time in the KOER Self-Test. When this happens, the engine runs and the PCM detects the Transmission Control switch signal does not change its status. To solve this issue, you should check the TCS switch for any apparent defects and replace it if necessary.
TCS Switch Signal Circuit
The second cause of Mazda Code P1780 is when the TCS switch signal circuit is open or shorted to ground. To fix this, you should inspect the wiring and ensure that the TCS switch signal circuit is connected correctly and not damaged. Furthermore, if the TCS switch signal circuit is shorted to VREF or system power, you should check if VREF and system power are functioning correctly, and test the TCS switch signal circuit.
TCS Switch Out-Of-Adjustment
The third cause of Mazda Code P1780 is when the TCS switch is damaged, out-of-adjustment, or failed. To fix this issue, you should replace the faulty TCS switch, if necessary, or adjust it to the proper setting.
PCM Has Failed
Finally, the fourth cause of Mazda Code P1780 is when the PCM has failed. You should replace the PCM with a new one to solve this issue.
Conclusion
In conclusion, the Mazda Code P1780 is triggered when the engine is running and the PCM detects the Transmission Control switch signal does not change its status in the CCM test. Knowing the causes and solutions for this code can help solve the issue quickly and efficiently, such as faulty wiring, a broken TCS switch, or even a PCM failure. By using the information in the table above, you can quickly troubleshoot and fix the Mazda Code P1780 issue.