16841/P0457/001111

16841/P0457/001111 - EVAP System: Leak Detected (Check Fuel Cap!)

Possible Symptoms

• Malfunction Indicator Light (MIL) (illuminated)
• Tank Cap Amber Warning (illuminated)
• Stored fault code(s) in Engine Control Module
• Possible fuel odor, especially near rear of vehicle after refueling

Possible Causes

• Fuel Tank Cap not closed properly
• Fuel Tank Cap seal damaged, hardened, or missing
• Evaporative Emission (EVAP) System leak (small to large)
• Leak Detection Pump (LDP) or Leak Detection Module fault
• Cracked or disconnected EVAP hoses or vapor lines
• Damaged charcoal canister or vent valve

Possible Solutions

• Inspect Fuel Tank Cap and seal for damage, debris, or missing O-ring
• Verify Fuel Tank Cap closes securely and clicks into place
• Check Fuel Filler Neck for damage or corrosion
• Perform Visual Inspection of Fuel Tank, EVAP hoses, canister, and fittings
• Perform EVAP leak test (with smoke test equipment)
• Check operation of Leak Detection Pump or system vent valve (if equipped)

North American market vehicles (only)

• For the 2019-2021 Tiguan 2.0L (DGUA) engine, please see Volkswagen Technical Tip 01-21-01 (2062754/1)
  • • https://static.nhtsa.gov/odi/tsbs/2021/MC-10189310-0001.pdf NHTSA

• For the 2018 Atlas 3.6L (CDVC) engine, please refer to Volkswagen UPDATE Technical Bulletin, July 19, 2018, 23X1 UPDATE – ECM Software Update (FED_EMS)
  • • https://static.nhtsa.gov/odi/tsbs/2018/MC-10150784-9999.pdf NHTSA

• For the 2015 - 2016 Passat, please refer to the Volkswagen Technical Tip (26-16-02) - Loose Evap Lines...
  • • https://static.nhtsa.gov/odi/tsbs/2016/MC-10121149-9999.pdf NHTSA