P073E: Unable to Engage Reverse
3 vehicles · 1 makes · $150-$3,500 repair
Most Reported On
P073E is an OBD-II diagnostic trouble code meaning “Unable to Engage Reverse.” This powertrain code indicates the transmission was unable to engage reverse gear when commanded by the transmission computer. It is part of the gear-engagement fault family on modern automatic transmissions. The computer detected that reverse did not engage as requested, suggesting a hydraulic, electrical, or internal mechanical issue. The vehicle may lose reverse function or enter limp mode, so it should be diagnosed promptly to avoid further 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
To diagnose P073E, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all 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 diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
FAQ
What does P073E mean?
P073E stands for "Unable to Engage Reverse." This powertrain code indicates the transmission was unable to engage reverse gear when commanded by the transmission computer. It is part of the gear-engagement fault family on modern automatic transmissions. The computer detected that reverse did not engage as requested, suggesting a hydraulic, electrical, or internal mechanical issue. The vehicle may lose reverse function or enter limp mode, so it should be diagnosed promptly to avoid further damage.
What are the most common causes of P073E?
The most common causes of P073E are: Faulty shift solenoid, Valve body fault or stuck valve, Low or contaminated transmission fluid, Worn reverse clutch/internal mechanical fault, 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 P073E?
Repair costs for P073E range from $150 to $3,500, depending on the vehicle and root cause.
Which vehicles are affected by P073E?
Au7o has documented P073E 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.