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P0455 on Cadillac CT5-V Blackwing: Fix & DLC Location

Factory diagnostic troubleshooting wire for fault code P0455 (P0455: Evaporative Emission Control System Leak Detected (Gross Leak)) specifically on the Cadillac CT5-V Blackwing (2022–2026, 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto)).

Cadillac CT5-V Blackwing
DIY Parts Estimate
$15 - $250 (DIY: $15 - $50)
CT5-V Blackwing OEM Fitment
Shop Labor Quote
$180 – $380
Based on $165/hr labor
Drivability Status
Drivable (Short Trip)
Low urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check P0455 On Another Cadillac Model:
Cadillac EscaladeCadillac Escalade-VCadillac CT5Cadillac CT5-V BlackwingCadillac XT5Cadillac Lyriq

1. Symptoms of P0455 on Cadillac CT5-V Blackwing

When the Engine Control Module (ECM/PCM) on your Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto)) logs fault code P0455, drivers commonly observe:

Check Engine Light on on Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto))
Gas cap loose warning message on dashboard on Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto))
Slight fuel vapor odor near rear of vehicle on Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto))
Cadillac CT5-V Blackwing OBD-II Port Location
The 16-pin diagnostic connector is located Driver A-pillar base kick panel. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Cadillac CT5-V Blackwing

Historical warranty claims and technical repair bulletins for Cadillac CT5-V Blackwing point to the following failure distribution:

55%
Missing, loose, or cracked gas cap seal (Cadillac OEM Part)
25%
Faulty EVAP purge control solenoid (Cadillac OEM Part)
12%
Stuck open EVAP vent valve (Cadillac OEM Part)
8%
Cracked EVAP charcoal canister vapor hose (Cadillac OEM Part)

3. Step-by-Step DIY Repair Guide for Cadillac CT5-V Blackwing

01
Inspect and Tighten the Gas Cap

Remove gas cap, inspect rubber O-ring for cracks, tighten until it clicks 3 times. on the Cadillac CT5-V Blackwing equipped with 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto).

Required Tool: None
02
Replace Gas Cap with OEM Replacement

If the cap rubber is dried or cracked, replace with genuine OEM cap ($15). on the Cadillac CT5-V Blackwing equipped with 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto).

Required Tool: New OEM Gas Cap
03
Test EVAP Purge Solenoid Under Hood

Disconnect electrical plug and vacuum hose. Apply 12V; verify valve seals tight when unpowered. on the Cadillac CT5-V Blackwing equipped with 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto).

Required Tool: 12V Probe, Vacuum Pump
04
Inspect EVAP Canister Vent Valve Near Gas Tank

Check vent valve for road salt corrosion or spider nest clogs. on the Cadillac CT5-V Blackwing equipped with 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto).

Required Tool: Flashlight, Jack Stands
05
Smoke Test EVAP System

Pump mineral oil smoke into EVAP port to reveal any hairline cracked lines. on the Cadillac CT5-V Blackwing equipped with 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto).

Required Tool: EVAP Smoke Machine

Other Common Fault Codes on Cadillac CT5-V Blackwing

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Cadillac CT5-V Blackwing:

4. Cadillac CT5-V Blackwing P0455 FAQs

What causes code P0455 to trigger on a Cadillac CT5-V Blackwing?

On the Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto)), P0455 is most frequently caused by Missing, loose, or cracked gas cap seal or Faulty EVAP purge control solenoid.

Where is the OBD-II port located on my Cadillac CT5-V Blackwing?

On the Cadillac CT5-V Blackwing, the 16-pin DLC diagnostic connector is located Driver A-pillar base kick panel. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Cadillac CT5-V Blackwing with code P0455?

Yes. Completely safe to drive, but emissions test will fail. Given that P0455 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.