why does my Toyota RAV4 Fifth Generation (2019-present) have a check engine light with no codes

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is parked on a level surface, and the engine is off.
• Disconnect the negative battery terminal to prevent electrical shocks.

2. Inspect Battery and Charging System

• Tools Required: Multimeter
• Check battery voltage:
  1. Set the multimeter to DC voltage.
  2. Measure battery voltage; it should be around 12.6 volts. If below 12.4 volts, charge or replace the battery.
• Test the alternator output while the engine is running:
  1. Start the engine and measure voltage at the battery; it should read between 13.7 to 14.7 volts.
  2. If not, check the alternator and connections.

3. Check Wiring and Ground Connections

• Tools Required: Visual inspection tools, multimeter
• Inspect the wiring harness near the ECU:
  1. Look for frayed wires or loose connections.
  2. Repair or replace any damaged wires.
• Check ground connections:
  1. Locate the ground points in the engine bay and ensure they are clean and secure.
  2. Tighten any loose connections and clean corroded points.

4. Inspect and Tighten Gas Cap

• Tools Required: None
• Remove the gas cap and inspect for damage or wear:
  1. Replace the gas cap if cracked or damaged.
  2. Reinstall and ensure it clicks securely.

5. Reset Check Engine Light

• Tools Required: OBD-II scanner
• Use the OBD-II scanner to clear any existing codes:
  1. Follow the scanner prompts to erase codes.
  2. Reconnect the negative battery terminal after resetting.
• Drive the vehicle for a short distance to see if the check engine light returns.