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P0705 on Mercedes-Benz GLC

Transmission Range Sensor Circuit Malfunction (PRNDL Input)

Factory diagnostic protocol and troubleshooting wire for fault code P0705 specifically for the Mercedes-Benz GLC (2020–2026, 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC).

Verified OEM Telemetry & Field Repair Tree
Mercedes-Benz GLC2020–2026
Mercedes-Benz GLC
SUV2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
GLC SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
High urgency level
Est. Repair Cost
$120 - $450 (DIY: $40 - $160)
Parts & Labor DIY
Check P0705 On Another Mercedes-Benz Model:
Diagnose P0705 on Specific GLC Model Year:

1. Symptoms of P0705 on Mercedes-Benz GLC

When the Engine Control Module (ECM/PCM) on your Mercedes-Benz GLC (2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC) logs fault code P0705, drivers commonly observe:

Check Engine Light on on Mercedes-Benz GLC (2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC)
Vehicle will not crank/start in Park (starts only in Neutral) on Mercedes-Benz GLC (2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC)
Gear indicator on dashboard (P R N D 1 2) is blank or displays wrong gear on Mercedes-Benz GLC (2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC)
Transmission shifts harshly or goes into 3rd gear limp mode on Mercedes-Benz GLC (2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC)
Reverse backup lights fail to illuminate on Mercedes-Benz GLC (2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC)
Mercedes-Benz GLC OBD-II Port Location
The 16-pin diagnostic connector is located Driver lower kick panel near hood release lever. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Mercedes-Benz GLC

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

55%
Misaligned or faulty Transmission Range Sensor / Neutral Safety Switch (NSS) (Mercedes-Benz OEM Part)
25%
Corroded or water-logged connector on transmission side (Mercedes-Benz OEM Part)
12%
Stretched or misadjusted shift linkage cable (Mercedes-Benz OEM Part)
8%
Broken internal switch contacts (Mercedes-Benz OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Mercedes-Benz GLC.

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

01
Check PRNDL Live Data

Move gear selector through all positions while monitoring scan tool TR PID to see which gear positions fail to register. on the Mercedes-Benz GLC equipped with 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC.

Required Tool: OBD-II Scanner
02
Inspect Shift Cable Alignment

Ensure the mechanical shift linkage fully clicks the transmission lever into the physical detent for Park and Neutral. on the Mercedes-Benz GLC equipped with 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC.

Required Tool: Pliers, Socket Set
03
Test Neutral Safety Switch Continuity

Use multimeter to check continuity across switch pins in Park, Reverse, Neutral, and Drive. on the Mercedes-Benz GLC equipped with 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC.

Required Tool: Digital Multimeter
04
Replace or Re-align Range Sensor

Loosen mounting bolts, use alignment pin to align sensor slot with transmission shaft in Neutral, torque bolts, or install new OEM sensor. on the Mercedes-Benz GLC equipped with 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC.

Required Tool: 10mm/12mm Sockets, Alignment Pin
05
Clear Trouble Codes and Verify Starting

Clear DTCs and confirm engine starts in Park and Neutral, reverse lights activate, and gear display is accurate. on the Mercedes-Benz GLC equipped with 2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC.

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Mercedes-Benz GLC (P0705)

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Direct-Fit Replacement Part

Mercedes-Benz GLC OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Mercedes-Benz GLC.

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Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
View on Amazon
Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

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Other Common Fault Codes on Mercedes-Benz GLC

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

4. Mercedes-Benz GLC P0705 FAQs

What causes code P0705 to trigger on a Mercedes-Benz GLC?

On the Mercedes-Benz GLC (2.0L Turbo 4-Cyl with EQ Boost (255HP) / AMG GLC 43 4MATIC), P0705 is most frequently caused by Misaligned or faulty Transmission Range Sensor / Neutral Safety Switch (NSS) or Corroded or water-logged connector on transmission side.

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

On the Mercedes-Benz GLC, the 16-pin DLC diagnostic connector is located Driver lower kick panel near hood release lever. 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 GLC with code P0705?

Caution. Vehicle may not start in Park, backup lights may not work, and transmission may lock in Limp Mode. Given that P0705 carries a High severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.