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P1457

Unable To Pull Vacuum In Tank.

  • Generic
  • Powertrain
  • Manufacturer code
  • Low severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
4
AreaAuxiliary emission controls
57
FaultThe specific fault in that area

What it means

P1457 means the evaporative emission (EVAP) system could not build the expected vacuum in the fuel tank during the control unit's leak test. The control unit commanded the purge valve open with the vent closed and the tank pressure sensor showed vacuum was not reached. This points to a leak, a purge path that is not drawing, or a vent that is not sealing.

Symptoms

  • Malfunction indicator lamp on
  • Fuel smell around the car, especially after parking
  • Fuel filler cap warning message on some models
  • Difficulty refuelling or the pump clicking off early
  • Failed emissions test with no obvious driveability problem

Possible causes

  • Fuel filler cap loose, missing, damaged or with a worn seallikely
  • Cracked, split or disconnected EVAP hoses or pipes, or a leaking quick-release connectorlikely
  • Purge valve stuck closed, blocked or with a faulty wiring connection, so no vacuum reaches the tankpossible
  • Vent valve stuck open or leaking, so the system cannot sealpossible
  • Leaking charcoal canister or damaged filler neck or fuel tank sealpossible
  • Faulty fuel tank pressure sensor or its wiring giving an incorrect readingrare
  • Blocked or kinked purge line between the canister and the intakerare

How to diagnose

  1. Read the stored and pending codes and the freeze frame data, noting fuel level, temperature and whether other EVAP codes are present
  2. Check the fuel filler cap is fitted, tightens properly and has an undamaged seal and filler neck sealing face
  3. Visually inspect EVAP hoses, pipes, connectors and the canister for cracks, disconnections, damage or fuel contamination
  4. Inspect the wiring and connectors at the purge valve, vent valve and tank pressure sensor for damage, corrosion or water
  5. With a scan tool, command the purge and vent valves and check they click, open and close as expected; the exact procedure depends on the model
  6. Check the tank pressure sensor reading against a known reference with the system open to atmosphere and compare it to the specification
  7. Apply vacuum or a smoke test to the EVAP system following the manufacturer's procedure to locate any leak
  8. Check the purge line for blockages and confirm vacuum is present at the purge valve with the engine running

How to fix

  • Replace the fuel filler cap with one of the correct type if it is loose, damaged or has a worn seal
  • Repair or replace leaking, cracked or disconnected EVAP hoses, pipes and connectors
  • Replace the purge valve or vent valve if it sticks, leaks or fails its electrical or functional test
  • Replace the charcoal canister, filler neck or tank seals if a leak is found there
  • Repair wiring faults or replace the tank pressure sensor if it is shown to be faulty
  • Clear the code after repair and complete a drive cycle to confirm the EVAP monitor passes

Can I keep driving?

Low severity

The car can normally be driven while you arrange a repair, as this fault does not usually affect safety or harm the engine. Fix it soon, because fuel vapour may escape and the car will fail an emissions test.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.

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