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P0672Mercedes-BenzMercedes-Benz PlatformModerate Severity

P0672 on Mercedes-Benz: Symptoms, Causes & DIY Fix

Official technical diagnostic wire for fault code P0672 (P0672: Cylinder 2 Glow Plug Circuit Malfunction) specifically affecting Mercedes-Benz vehicles (C-Class, E-Class, S-Class, GLC, GLE, GLS, G-Class, CLA, GLA, EQE, EQS, AMG GT).

DIY Parts Estimate
$100 - $250 (DIY: $20 - $50)
Mercedes-Benz OEM Direct Fit
Shop Labor Quote
$180 – $380
Based on $185/hr labor
Drivability Status
Drivable (Short Trip)
Moderate urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check P0672 On Another Make:
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1. Symptoms of P0672 on Mercedes-Benz

When the Engine Control Module (ECM/PCM) on your Mercedes-Benz logs fault code P0672, drivers commonly observe:

System alert or indicator light illuminated (P0672) on Mercedes-Benz (C-Class, E-Class)
Intermittent performance throttling or unexpected operation halts on Mercedes-Benz (C-Class, E-Class)
Audible sensor relay clicking or anomalous status telemetry in dashboard logs on Mercedes-Benz (C-Class, E-Class)
Degraded operational throughput or error dialog popups on startup on Mercedes-Benz (C-Class, E-Class)
Readiness monitors failing state emissions or system compliance audits on Mercedes-Benz (C-Class, E-Class)

2. Most Likely Causes on Mercedes-Benz

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

55%
Component aging, oxidation, or degraded internal circuit element (Cylinder 2 Glow Plug) (Mercedes-Benz OEM Part)
25%
Wiring harness abrasion, loose terminal pin, or ground voltage float (Mercedes-Benz OEM Part)
12%
Outdated firmware microcode or incompatible software driver update (Mercedes-Benz OEM Part)
8%
Thermal stress or excessive operational duty-cycle fatigue (Mercedes-Benz OEM Part)
8%
Contamination from carbon buildup, moisture ingress, or dirty filtration (Mercedes-Benz OEM Part)

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

01
Connect Diagnostic Scanner / Logging Monitor to Retrieve Telemetry

Interface with the diagnostic port or system console using verified scanning hardware. Record freeze-frame data, active sub-codes, and timestamps to isolate whether P0672 is static or intermittent. on Mercedes-Benz vehicles (C-Class, E-Class).

Required Tool: Glow plug socket (10mm)
02
Perform Physical & Electrical Circuit Inspection

Visually inspect the physical component (Cylinder 2 Glow Plug), connector pins, and associated wiring harnesses for signs of corrosion, thermal melting, or loose grounding clips. on Mercedes-Benz vehicles (C-Class, E-Class).

Required Tool: Multimeter, Flashlight, Contact Cleaner Spray
03
Component Testing & Resistance / Voltage Verification

Measure reference voltages and resistance thresholds against manufacturer factory specifications. Replace any component failing nominal impedance tolerances. on Mercedes-Benz vehicles (C-Class, E-Class).

Required Tool: Glow plug socket (10mm)
04
Execute Component Replacement or Software Configuration Patch

Install genuine OEM replacement hardware or execute registry / service commands. Ensure all mounting bolts are torqued to factory specifications. on Mercedes-Benz vehicles (C-Class, E-Class).

Required Tool: Standard Hand Tool Set / Terminal Commands
05
Clear Diagnostic Trouble Code & Complete Verification Drive Cycle

Erase the fault code from non-volatile memory. Perform a standard verification cycle (e.g. 15-minute mixed drive or system stress benchmark) to ensure monitors reset to 'Ready' state without recurrent fault flags. on Mercedes-Benz vehicles (C-Class, E-Class).

Required Tool: OBD-II Code Reader / Diagnostic Suite

4. Mercedes-Benz P0672 FAQs

What causes code P0672 to trigger on a Mercedes-Benz?

On Mercedes-Benz vehicles, P0672 is most frequently caused by Component aging, oxidation, or degraded internal circuit element (Cylinder 2 Glow Plug) or Wiring harness abrasion, loose terminal pin, or ground voltage float. Factory sensor degradation or wiring harness wear near the engine bay are common factors.

Can I safely drive my Mercedes-Benz with code P0672?

Yes, for temporary operations. However, resolve promptly to maintain optimal efficiency and prevent cascade failures. Given that P0672 carries a Moderate severity rating on Mercedes-Benz vehicles, we advise performing diagnostic scanning via the OBD-II port before extended driving.

How much does it cost to fix P0672 on a Mercedes-Benz?

DIY replacement parts typically range between $100 - $250 (DIY: $20 - $50). If serviced at an authorized Mercedes-Benz dealership, expect an additional $120–$250 in professional labor based on their $185/hr hourly rate.