P073C: Transmission Stuck In Gear 7 / Gear 7 Engagement Fault
3 vehicles · 1 makes · $150-$3,500 repair
Most Reported On
P073C is an OBD-II diagnostic trouble code meaning “Transmission Stuck In Gear 7 / Gear 7 Engagement Fault.” This powertrain code relates to the transmission being unable to properly disengage or commanded gear control, generally indicating it is stuck in 7th gear (or cannot leave gear 7 as commanded). It is part of a family of newer transmission gear-engagement codes used on multi-speed automatics. The transmission computer detected that the actual gear state did not match what it commanded. This can cause harsh operation, limited gear range, or limp mode, and warrants prompt diagnosis to avoid further transmission damage. This code is most commonly reported on 2019-2023 Mercedes-Benz A-Class (A220), 2020-2025 Mercedes-Benz GLB (GLB250), and 2013-2019 Mercedes-Benz B-Class (B250, B250e), with repair costs ranging from $150 to $3,500.
Common Causes
Typical Repair Cost
Based on 3 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
This is a powertrain code, so a basic OBD-II reader can read it. These read P073C.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple code reader for engine (P) codes on many compatible OBD-II vehicles. It does not support every vehicle or hybrid/EV application, and it does NOT read body, chassis or network codes; confirm exact-vehicle compatibility before buying.
- Read & clear engine (P) codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth scanner with a companion app that reads beyond the engine module — ABS, SRS and transmission — plus manufacturer-specific codes on many vehicles.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X V3.0 Elite OBD-II Scanner
by LAUNCH
Handheld scanner covering the four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level tablet with all-system coverage and bi-directional control, so you can command a module rather than only read it.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
What you can do yourself, and what needs a shop
Reading the code, clearing it, and watching whether it returns is a driveway job with the right scanner. These steps are not:
- Module programming or software updates — needs the manufacturer software or a J2534 pass-through with a paid subscription.
- Replacing a control module — most are VIN-programmed and immobilizer-registered, so a new one does nothing until it is coded to your car.
- Airbag/SRS component work — a stored fault can deploy a live device.
If the vehicle is still under warranty, check for an open recall or technical service bulletin before buying anything — the repair may already be covered.
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Vehicles Affected (3)
FAQ
What does P073C mean?
P073C stands for "Transmission Stuck In Gear 7 / Gear 7 Engagement Fault." This powertrain code relates to the transmission being unable to properly disengage or commanded gear control, generally indicating it is stuck in 7th gear (or cannot leave gear 7 as commanded). It is part of a family of newer transmission gear-engagement codes used on multi-speed automatics. The transmission computer detected that the actual gear state did not match what it commanded. This can cause harsh operation, limited gear range, or limp mode, and warrants prompt diagnosis to avoid further transmission damage.
What are the most common causes of P073C?
The most common causes of P073C are: Faulty shift solenoid or valve body fault, Low or contaminated transmission fluid, Stuck or worn valve body passages, Internal mechanical fault (clutch/clutch pack), Wiring or connector fault in the transmission circuit, Faulty transmission control module. The specific cause varies by vehicle.
How much does it cost to fix P073C?
Repair costs for P073C range from $150 to $3,500, depending on the vehicle and root cause.
Which vehicles are affected by P073C?
Au7o has documented P073C across 3 vehicle models from 1 manufacturers: Mercedes-Benz.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.