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P0135 on Mercedes-Benz GLE: Fix & DLC Location

Factory diagnostic troubleshooting wire for fault code P0135 (O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)) specifically on the Mercedes-Benz GLE (2020–2026, 2.0L Turbo / 3.0L Turbo I6 (GLE 450 375HP) / 4.0L V8 GLE 580).

Mercedes-Benz GLE
DIY Parts Estimate
$80 - $240 (DIY Sensor: $45)
GLE OEM Fitment
Shop Labor Quote
$180 – $380
Based on $185/hr labor
Drivability Status
Drivable (Short Trip)
Low to Medium urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check P0135 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 P0135 on Mercedes-Benz GLE

When the Engine Control Module (ECM/PCM) on your Mercedes-Benz GLE (2.0L Turbo / 3.0L Turbo I6 (GLE 450 375HP) / 4.0L V8 GLE 580) logs fault code P0135, drivers commonly observe:

Check Engine Light on on Mercedes-Benz GLE (2.0L Turbo / 3.0L Turbo I6 (GLE 450 375HP) / 4.0L V8 GLE 580)
Slightly increased fuel consumption on short trips on Mercedes-Benz GLE (2.0L Turbo / 3.0L Turbo I6 (GLE 450 375HP) / 4.0L V8 GLE 580)
Failed state emissions inspection on Mercedes-Benz GLE (2.0L Turbo / 3.0L Turbo I6 (GLE 450 375HP) / 4.0L V8 GLE 580)
Mercedes-Benz GLE OBD-II Port Location
The 16-pin diagnostic connector is located Driver footwell directly above parking brake pedal. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Mercedes-Benz GLE

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

55%
Burnt-out internal heating element in upstream oxygen sensor (Mercedes-Benz OEM Part)
25%
Blown O2 sensor heater fuse (Mercedes-Benz OEM Part)
12%
Melted or damaged sensor wiring near exhaust manifold (Mercedes-Benz OEM Part)
8%
Excessive circuit resistance (Mercedes-Benz OEM Part)

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

01
Check the Heater Fuse

Locate the under-hood fuse box and test the O2 sensor heater fuse with a multimeter or test light. on the Mercedes-Benz GLE equipped with 2.0L Turbo / 3.0L Turbo I6 (GLE 450 375HP) / 4.0L V8 GLE 580.

02
Measure Sensor Heater Resistance

Unplug the Bank 1 Sensor 1 connector and test resistance between the two heater pins (typically 3 to 15 ohms). on the Mercedes-Benz GLE equipped with 2.0L Turbo / 3.0L Turbo I6 (GLE 450 375HP) / 4.0L V8 GLE 580.

03
Replace Upstream O2 Sensor

Use an O2 sensor socket wrench to remove the old sensor from the exhaust manifold and install an OEM-spec replacement with anti-seize on the threads. on the Mercedes-Benz GLE equipped with 2.0L Turbo / 3.0L Turbo I6 (GLE 450 375HP) / 4.0L V8 GLE 580.

Other Common Fault Codes on Mercedes-Benz GLE

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Mercedes-Benz GLE:

4. Mercedes-Benz GLE P0135 FAQs

What causes code P0135 to trigger on a Mercedes-Benz GLE?

On the Mercedes-Benz GLE (2.0L Turbo / 3.0L Turbo I6 (GLE 450 375HP) / 4.0L V8 GLE 580), P0135 is most frequently caused by Burnt-out internal heating element in upstream oxygen sensor or Blown O2 sensor heater fuse.

Where is the OBD-II port located on my Mercedes-Benz GLE?

On the Mercedes-Benz GLE, the 16-pin DLC diagnostic connector is located Driver footwell directly above parking brake pedal. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Mercedes-Benz GLE with code P0135?

Yes, vehicle is safe to drive, but will stay in open-loop mode longer upon startup. Given that P0135 carries a Low to Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.