What is the consequence of a defective start enable relay in vehicles with auto-shift transmission?

A defective start enable relay in vehicles equipped with an auto-shift transmission can indeed allow the engine to start in any gear. Typically, the start enable relay is designed to prevent the engine from starting unless the vehicle is in a specific gear, usually neutral or park. This safety feature ensures that the vehicle doesn’t lurch forward or backward unexpectedly when starting the engine.

When the start enable relay functions correctly, it acts as a safeguard against starting the vehicle while it’s in gear. However, if the relay is malfunctioning or defective, it may fail to interrupt this functionality. As a result, the engine could be started while the vehicle is in a drive gear, which poses a significant safety risk. Operators may inadvertently engage the throttle, leading to potential accidents or damage to the vehicle.

This highlights the importance of the start enable relay in maintaining proper operational safety in vehicles with auto-shift transmissions. Other options presented do not directly relate to the defect of the start enable relay regarding its role in engine start conditions, which reinforces the accuracy of this choice.