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P0455Mercedes-BenzMercedes-Benz S-Class GuideLow Severity

P0455 on Mercedes-Benz S-Class: 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 S-Class vehicles equipped with 3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP).

DIY Parts Estimate
$15 - $250 (DIY: $15 - $50)
S-Class 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-ClassMercedes-Benz E-ClassMercedes-Benz S-ClassMercedes-Benz GLCMercedes-Benz GLEMercedes-Benz GLSMercedes-Benz G-Class

1. Symptoms of P0455 on Mercedes-Benz S-Class

When the Engine Control Module (ECM/PCM) on your Mercedes-Benz S-Class (3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP)) logs fault code P0455, drivers commonly observe:

Check Engine Light on on Mercedes-Benz S-Class (3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP))
Gas cap loose warning message on dashboard on Mercedes-Benz S-Class (3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP))
Slight fuel vapor odor near rear of vehicle on Mercedes-Benz S-Class (3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP))
Mercedes-Benz S-Class OBD-II Port Location
The 16-pin diagnostic connector is located Driver lower dash panel beneath protective hinged flap. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Mercedes-Benz S-Class

Historical warranty claims and technical repair bulletins for Mercedes-Benz S-Class 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)
8%
Cracked EVAP charcoal canister vapor hose (Mercedes-Benz OEM Part)

3. Step-by-Step DIY Repair Guide for Mercedes-Benz S-Class

01
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 S-Class equipped with 3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP).

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 Mercedes-Benz S-Class equipped with 3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP).

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 Mercedes-Benz S-Class equipped with 3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP).

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 Mercedes-Benz S-Class equipped with 3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP).

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 Mercedes-Benz S-Class equipped with 3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP).

Required Tool: EVAP Smoke Machine

4. Mercedes-Benz S-Class P0455 FAQs

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

On the Mercedes-Benz S-Class (3.0L Turbo I6 (S 500) / 4.0L Bi-Turbo V8 (M176 S 580 496HP)), 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 S-Class 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 dash panel beneath protective hinged flap before extended highway driving.

Where is the diagnostic port located on the Mercedes-Benz S-Class?

The 16-pin OBD-II DLC connector on the Mercedes-Benz S-Class is situated driver lower dash panel beneath protective hinged flap. It requires no special tools to plug in a standard scanner.

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

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.