When the "D" light on your Honda Pilot 2004 starts blinking, it typically indicates a problem with the transmission. The blinking "D" light is often associated with a diagnostic trouble code (DTC) stored in the vehicle's transmission control module (TCM). This indicates that the TCM has detected an issue and is trying to alert you to it.
There can be various reasons why the "D" light is blinking, including:
Transmission Malfunction: The blinking "D" light may indicate a fault within the transmission system, such as a sensor malfunction, solenoid problem, or fluid pressure issue.
Overheating: Excessive heat in the transmission can cause the "D" light to blink. It could be due to low transmission fluid level, fluid overheating, or a problem with the transmission cooler.
Electrical Issue: A problem with the electrical circuitry related to the transmission, such as a faulty sensor or wiring, can trigger the blinking "D" light.
When the "D" light is blinking, it is advisable to have your vehicle diagnosed by a qualified technician or take it to a Honda service center. They can connect a diagnostic scanner to the vehicle's OBD-II (On-Board Diagnostics) port to retrieve the specific trouble code(s) stored in the TCM. This will provide more information about the nature of the problem and help identify the necessary repairs or adjustments.
It's important to address any transmission issues promptly to prevent further damage and ensure the continued safe operation of your vehicle.