P1457

Code

Generic P — Powertrain

Unable To Pull Vacuum In Tank

Brand: Generic

Type: P — Powertrain

Views: UK: 43 EN: 64 RU: 39

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty leak detection pump or vacuum pump (LDV/EVAP pump)
Open or leaking EVAP vent/control valve
Large external leak (loose or missing fuel filler cap, disconnected/rotten hoses)
Blocked or collapsed vent, vent line, or port
Clogged/saturated charcoal canister or internal canister restriction
Faulty fuel tank pressure (FTP) / EVAP pressure sensor or wiring/connectors

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
Failed EVAP readiness or failed emissions test
Strong fuel odor near fuel tank or filler area
Difficulty achieving or holding vacuum during manufacturer EVAP test
Possible poor fuel smell in cabin or near rear of vehicle

What to check

Read and record freeze frame and all related EVAP codes; check for pending codes
Use a scan tool to monitor FTP/EVAP sensor, LD/Vacuum pump command, and vent valve status during an EVAP test
Visually inspect fuel cap, filler neck, vent lines, and connectors for damage or loose fittings
Listen for operation of leak detection/vacuum pump and verify vent valve open/close on command
Perform a smoke test of the EVAP system to locate external leaks
Check resistance/voltage at EVAP solenoids and pump; inspect wiring and connectors for corrosion or damage

Signal parameters

Fuel Tank Pressure (FTP) or EVAP system pressure sensor reading (kPa or inHg) during test
Command status of EVAP vent control valve (open/closed)
Command/status of leak detection pump or vacuum pump (on/off, duty cycle)
Monitor vacuum/pressure ramp and whether it reaches/holds target value during test
Related PIDs: EVAP purge valve state, fuel cap state (if available), and any EVAP fault counters

Diagnostic algorithm

Read codes and freeze frame; record current EVAP-related PIDs with a capable scan tool. Confirm P1457 is current and note other EVAP codes.
Inspect fuel filler cap: ensure correct type, check gasket condition and proper seating. Replace cap if damaged and retest.
Visually inspect all accessible EVAP hoses, connectors, and the filler neck for cracks, disconnections, or obvious leaks.
Command the EVAP vent control valve and leak-detection pump from the scan tool. Confirm the pump clicks/runs and the vent valve changes state; verify appropriate FTP sensor response.
If the pump does not run or the vent valve does not operate, check power/ground and control wiring; repair any open/corroded circuits and bench-test components where possible.
Perform a smoke test of the EVAP system (safe, shop-grade smoke machine) to find external leaks or restrictions. Pay attention to filler neck, tank seams, hoses, canister, and vent valve areas.
If no external leaks are found but vacuum cannot be held, inspect or remove the charcoal canister and check for internal blockages or saturation. Replace if contaminated.
If vacuum pump runs but pressure reading is incorrect, verify FTP/EVAP pressure sensor operation and wiring. Replace sensor if out of spec.
If internal tank check valves or rollover valves are suspected (internal to tank), consult vehicle service manual for tank removal/inspection or tank internal repair procedures.
After repairs, clear codes, run the EVAP monitor or drive cycle to confirm the system can pull/hold vacuum and that P1457 does not return.

Likely causes

Vent control valve stuck open or not commanded/grounded properly preventing vacuum
Leaking vent hoses or poor sealing at filler neck preventing vacuum hold
Leaky or failed leak detection/vacuum pump unable to generate required vacuum
Clogged or saturated charcoal canister preventing flow to/from tank
Faulty FTP/EVAP pressure sensor giving incorrect feedback

Fault status

⚠️ Status

P1457 — EVAP system/PCM detected inability to pull or hold vacuum in the fuel tank during an EVAP test. Possible causes include failed leak-detection pump, open vent valve, large leak (fuel cap/hose), or blocked EVAP components. Further testing required.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5-4.0 hours