why does my Volkswagen Passat B8 (2015-2022) check engine light keep coming on

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the negative battery terminal to prevent electrical shorts.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Screwdrivers
• Multimeter

2. Addressing Error Codes

• Use the OBD-II scanner to retrieve error codes.
• Research the codes to identify specific components involved in the issue (e.g., P0171 for lean fuel mixture).

3. Inspect and Replace Components

• Gas Cap:

  • Check for cracks or seal damage.
  • Replace if necessary (use OEM recommended part).

• Ignition System:

  • Remove spark plugs using a socket wrench.
  • Inspect for wear; replace if necessary (gap according to manufacturer specifications).
  • Check ignition coils for cracks or faults; replace if needed.

• Air Filter:

  • Remove the air filter housing cover.
  • Replace the air filter if it is dirty or clogged.

• Fuel System:

  • Test the fuel pressure using a fuel pressure gauge.
  • Replace the fuel filter if restricted (if applicable).

4. Reassemble and Test

• Reinstall all components securely.
• Reconnect the negative battery terminal.
• Clear error codes with the OBD-II scanner.