What should I do if my 2020 Highlander won't start?

If your 2020 Toyota Highlander won't start, it can be due to various issues ranging from a dead battery to a more complex engine problem. Below is a detailed diagnostic and repair guide to help you troubleshoot and potentially resolve the issue.

Step 1: Check the Battery

Symptoms to Look For:

• Dashboard lights are dim or flickering.
• No response when turning the key.

Tools Required:

• Multimeter
• Battery terminal cleaner or wire brush
• Jumper cables (if needed)

Instructions:

1. Visual Inspection: Check for corrosion on battery terminals. Clean them using a battery terminal cleaner or wire brush.
2. Voltage Check: Use a multimeter to measure the battery voltage. A healthy battery should read approximately 12.6 volts or higher.
   • If below 12.4 volts: The battery may be weak or dead.
3. Jump Start: If the battery voltage is low, attempt to jump-start the vehicle using jumper cables and another vehicle.
   • If the vehicle starts, consider replacing the battery if it repeatedly fails to hold a charge.

Step 2: Check the Fuses

Symptoms to Look For:

• No electrical components are functioning.

Tools Required:

• Fuse puller or flathead screwdriver
• Replacement fuses

Instructions:

1. Locate the Fuse Box: Consult the owner’s manual for the location of the fuse box (typically under the dashboard or in the engine compartment).
2. Inspect Fuses: Check for any blown fuses, especially those related to the ignition system (e.g., "IG1" or "START" fuses).
   • Replace any blown fuses with the correct amperage rating.

Step 3: Inspect the Starter Motor

Symptoms to Look For:

• A single click or a series of clicks when the key is turned.

Tools Required:

• Multimeter or test light
• Wrench set
• Screwdriver

Instructions:

1. Locate the Starter: Typically found near the bottom of the engine, near the transmission.
2. Check Connections: Inspect wiring and connectors for tightness and corrosion.
3. Test the Starter:
   • Use a multimeter to check voltage at the starter solenoid terminal while a helper turns the key to the "start" position. You should see battery voltage (around 12 volts).
   • If voltage is present but the starter does not engage, the starter may be faulty and needs replacement.

Step 4: Check the Ignition System

Symptoms to Look For:

• Engine cranks but does not start.

Tools Required:

• Spark plug socket
• OBD-II scanner (for diagnosing codes)

Instructions:

1. Check for Spark:
   • Remove a spark plug and reconnect it to the ignition coil; ground it against the engine.
   • Crank the engine and observe if there's a spark. If there’s no spark, there may be an issue with the ignition coils or the ignition module.
2. Scan for Codes:
   • Use an OBD-II scanner to check for any stored trouble codes that might indicate a problem (e.g., crankshaft position sensor failure).

Step 5: Fuel System Check

Symptoms to Look For:

• Engine cranks but does not start, potential smell of gasoline.

Tools Required:

• Fuel pressure gauge
• Safety glasses

Instructions:

1. Check Fuel Pressure:
   • Locate the fuel pressure test port on the fuel rail.
   • Connect the fuel pressure gauge to the port and turn the ignition to the ON position (without cranking).
   • Check the pressure against specifications in the service manual (typically around 50-60 psi).
   • If pressure is low, check for clogged fuel filters or failing fuel pumps.

Repair Instructions

Battery Replacement (if needed)

1. Disconnect the negative terminal first, then the positive.
2. Remove any hold-down brackets and lift the battery out.
3. Place the new battery in the tray, secure it, and reconnect the terminals (positive first, then negative).

Starter Motor Replacement (if needed)

1. Disconnect battery.
2. Remove bolts securing the starter and disconnect wiring.
3. Install the new starter and reconnect wiring and bolts.
4. Reconnect the battery and test.

Ignition Coil Replacement (if needed)

1. Disconnect battery.
2. Remove the engine cover (if equipped).
3. Unplug the electrical connector from the ignition coil.
4. Remove bolts securing the coil and replace it with a new one.
5. Reconnect everything and test.

Final Steps

1. Once repairs are complete, attempt to start the vehicle again.
2. If the vehicle starts, monitor for any warning lights or unusual behavior.
3. If the vehicle still does not start after following these steps, consider consulting a professional technician for further diagnosis.

Conclusion

By following these detailed steps, you should be able to diagnose and potentially fix the starting issue with your 2020 Toyota Highlander. Always remember to exercise caution and consult professional help if unsure about any procedures.