What causes the Highlander AWD to fail to start when switched to 2AWD?
2 Answers
Highlander AWD failing to start when switched to 2AWD is due to a four-wheel drive system malfunction. Possible causes include a dead battery, lack of fuel, missing antifreeze, or incorrect gear selection. Details are as follows: Dead battery: This can be caused by leaving headlights on for an extended period or the battery reaching the end of its lifespan. Regularly check the battery's condition and replace it promptly if it's no longer functional. Lack of fuel: If the fuel gauge shows the level below the red line, the vehicle naturally won't start. Also, pay attention to the quality of the fuel. Missing antifreeze: Some drivers use water or low-quality antifreeze, which can freeze in extremely cold winter conditions, blocking the entire cooling system and cracking the engine. This prevents the car's water pump from operating, leading to a failure to start and damaging other engine components. Always use or replace antifreeze as needed. Incorrect gear selection: The Highlander must be in P (Park) or N (Neutral) to start. If it's in R (Reverse) or D (Drive), it won't start. Always check the gear position before starting the vehicle.
From my experience, when a Highlander fails to start after switching from AWD to 2AWD, it's mostly due to issues with the electronic control system. During AWD switching, the system performs a self-check. If sensors or modules malfunction—such as a faulty mode switch or loose wiring connections—the computer may lock the engine to prevent damage. Additionally, insufficient battery power is a common culprit. Mode switching consumes electricity, and if the battery is old or undercharged, starting becomes impossible. Other possibilities include a stuck starter or key recognition errors, especially when smart key batteries are dead. Regular maintenance is key: monitor battery voltage and service the drivetrain periodically to avoid low-power states. If this issue arises, don’t panic—try switching modes multiple times or disconnecting the battery for 5 minutes before retrying. If unresolved, visit a professional repair shop promptly—safety first.
