Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / P1450 — Inability of Evaporative Emission Control System to Bleed Fuel Tank

P1450 — Inability of Evaporative Emission Control System to Bleed Fuel Tank

Detailed page for trouble code P1450.

34,421codes
59brands
11,925generic
22,496specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

P1450

MERCURY P — Powertrain

Inability of Evaporative Emission Control System to Bleed Fuel Tank

Brand: MERCURY
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Blocked or collapsed vent/bleed hose
  • Faulty canister vent/vent control valve (stuck closed)
  • Clogged or saturated charcoal canister
  • Faulty fuel tank pressure (FTP) sensor or incorrect readings
  • Restricted or stuck rollover/anti-siphon valve in filler neck
  • Installed aftermarket parts or improper repair causing restriction

Symptoms

  • Check Engine Light (MIL) is ON with P1450 stored
  • Failing readiness or EVAP monitor during emissions test
  • Possible fuel smell near fill area or canister
  • Difficulty filling tank or slow fill (depending on restriction)
  • No obvious fuel leaks; fault relates to venting/bleed function

What to check

  • Verify stored freeze frame and other EVAP-related codes (P0440, P0446, P0455, etc.)
  • Check fuel cap for proper fit and condition; inspect filler neck/rollover valve
  • Visually inspect EVAP hoses and connections for kinks, crushes, or blockages
  • Use a scan tool to monitor fuel tank pressure (FTP) sensor and command vent/purge valves
  • Measure vent control valve coil resistance and verify operation with a bidirectional tester
  • Perform a smoke test or pressure/vacuum test of the EVAP lines to find restrictions or leaks

Signal parameters

  • Fuel Tank Pressure (FTP) sensor voltage/pressure response during key ON and commanded bleed
  • PCM command to canister vent/vent control valve (open/closed) and actual valve response
  • Purge valve command and resulting purge flow when applicable
  • Vent valve coil resistance and ground continuity at connector
  • Pressure decay or change rates during EVAP test (smoke/pressure test results)

Diagnostic algorithm

  1. Verify the trouble code and related EVAP codes. Record freeze frame and vehicle conditions when code set.
  2. Check for Technical Service Bulletins (TSBs) or recalls for EVAP issues on this Mercury model/year.
  3. Perform a visual inspection: fuel cap, filler neck, rollover valve, canister, hoses and connectors for damage or restriction.
  4. With a scan tool, monitor FTP sensor readings. Command the vent control valve open/closed and observe FTP response. No change indicates blocked vent or valve failure.
  5. Activate the canister vent/vent control valve with a bidirectional scan tool or apply bench power to the valve to confirm it opens. Check coil resistance; compare to service spec.
  6. Perform a smoke test or introduce low-pressure air into the EVAP plumbing from the filler neck/canister side to locate blockages or collapsed hoses. Pay attention to filler neck and rollover valve.
  7. If vent path is blocked, trace and clear or replace the offending hose, valve, or canister. If charcoal canister is saturated or internally clogged, replace it.
  8. Test the FTP sensor and wiring if readings are inconsistent with expected pressure changes when commanding venting. Repair or replace as needed.
  9. After repairs, clear codes and run readiness/EVAP monitor. Re-check for presence of code and correct operation.

Likely causes

  • Canister vent/vent control valve stuck closed or not commanded open
  • Blocked vent line between tank and canister (debris, collapsed hose)
  • Clogged charcoal canister preventing venting
  • Fuel tank pressure sensor providing incorrect data or failed
  • Filler neck/rollover valve obstruction

Fault status

⚠️ Status
EVAP system unable to bleed/vent fuel tank — venting path restricted or vent control malfunction.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-2.5 hours

Similar codes

P0440 P0442 P0455 P0456 P0446 P0449
296

Browse 296 MERCURY manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MERCURY

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .