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P0455

Mercedes-Benz GLS GuideLow Severity

P0455 on Mercedes-Benz GLS: Symptoms, Causes & DIY Fix

Official technical diagnostic wire for fault code P0455 (P0455: Evaporative Emission Control System Leak Detected (Gross Leak)) specifically affecting Mercedes-Benz GLS vehicles equipped with 3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach).

DIY Parts Estimate

$15 - $250 (DIY: $15 - $50)

GLS Direct Fit

Shop Labor Quote

$180 – $380

Based on $185/hr labor

Drivability Status

Drivable (Short Trip)

Low urgency level

Est. DIY Time

45 – 90 Min

Basic hand tools

Check P0455 On Another Mercedes-Benz Model:

Mercedes-Benz C-Class Mercedes-Benz E-Class Mercedes-Benz S-Class Mercedes-Benz GLC Mercedes-Benz GLE Mercedes-Benz GLS Mercedes-Benz G-Class

1. Symptoms of P0455 on Mercedes-Benz GLS

When the Engine Control Module (ECM/PCM) on your Mercedes-Benz GLS (3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach)) logs fault code P0455, drivers commonly observe:

Check Engine Light on on Mercedes-Benz GLS (3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach))

Gas cap loose warning message on dashboard on Mercedes-Benz GLS (3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach))

Slight fuel vapor odor near rear of vehicle on Mercedes-Benz GLS (3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach))

Mercedes-Benz GLS OBD-II Port Location

The 16-pin diagnostic connector is located Driver lower knee bolster trim panel. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Mercedes-Benz GLS

Historical warranty claims and technical repair bulletins for Mercedes-Benz GLS point to the following failure distribution:

55%

Missing, loose, or cracked gas cap seal (Mercedes-Benz OEM Part)

25%

Faulty EVAP purge control solenoid (Mercedes-Benz OEM Part)

12%

Stuck open EVAP vent valve (Mercedes-Benz OEM Part)

Cracked EVAP charcoal canister vapor hose (Mercedes-Benz OEM Part)

3. Step-by-Step DIY Repair Guide for Mercedes-Benz GLS

Inspect and Tighten the Gas Cap

Remove gas cap, inspect rubber O-ring for cracks, tighten until it clicks 3 times. on the Mercedes-Benz GLS equipped with 3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach).

Required Tool: None

Replace Gas Cap with OEM Replacement

If the cap rubber is dried or cracked, replace with genuine OEM cap ($15). on the Mercedes-Benz GLS equipped with 3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach).

Required Tool: New OEM Gas Cap

Test EVAP Purge Solenoid Under Hood

Disconnect electrical plug and vacuum hose. Apply 12V; verify valve seals tight when unpowered. on the Mercedes-Benz GLS equipped with 3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach).

Required Tool: 12V Probe, Vacuum Pump

Inspect EVAP Canister Vent Valve Near Gas Tank

Check vent valve for road salt corrosion or spider nest clogs. on the Mercedes-Benz GLS equipped with 3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach).

Required Tool: Flashlight, Jack Stands

Smoke Test EVAP System

Pump mineral oil smoke into EVAP port to reveal any hairline cracked lines. on the Mercedes-Benz GLS equipped with 3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach).

Required Tool: EVAP Smoke Machine

4. Mercedes-Benz GLS P0455 FAQs

What causes code P0455 to trigger on a Mercedes-Benz GLS?

On the Mercedes-Benz GLS (3.0L Turbo I6 (GLS 450) / 4.0L Bi-Turbo V8 (GLS 580 / Maybach)), P0455 is most frequently caused by Missing, loose, or cracked gas cap seal or Faulty EVAP purge control solenoid. Factory sensor degradation or wiring harness wear near the engine bay are common factors.

Can I safely drive my Mercedes-Benz GLS with code P0455?

Yes. Completely safe to drive, but emissions test will fail. Given that P0455 carries a Low severity rating on Mercedes-Benz vehicles, we advise performing diagnostic scanning via the OBD-II port located driver lower knee bolster trim panel before extended highway driving.

Where is the diagnostic port located on the Mercedes-Benz GLS?

The 16-pin OBD-II DLC connector on the Mercedes-Benz GLS is situated driver lower knee bolster trim panel. It requires no special tools to plug in a standard scanner.

How much does it cost to fix P0455 on a Mercedes-Benz GLS?

DIY replacement parts typically range between $15 - $250 (DIY: $15 - $50). If serviced at an authorized Mercedes-Benz dealership, expect an additional $120–$250 in professional labor based on their $185/hr hourly rate.