- Engine / equipment
- Mercedes-Benz A-Class (W177), CLA (118), GLA (247) and GLB (247) with the 8G-DCT dual-clutch transmission (724.1)
- Period mentioned
- 2021–2023 (US model years)
- Symptoms
- Transmission fault message, engine warning light on and the gearbox shifts into neutral (N); the fault disappears after switching off and restarting.
- Possible cause described
- The transmission computer alone detects an overvoltage (over 16 V) and stores code P056300, although no other control unit sees it. Mercedes-Benz fixes it with a transmission software update (technical note LI27.19-P-080823).
- Check for the garage
- Ask the workshop to check whether code P056300 was stored with a voltage of 15.75 to 16.5 V and update the transmission software according to note LI27.19-P-080823.
- Cost cited in the source
- No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.
KNOWN FAULT · Mercedes-Benz
Transmission fault message and shift to neutral from a false overvoltage (8G-DCT of the A-Class, CLA, GLA and GLB 2021–2023)
Sources are not verified in real time and no entry confirms that your car is affected.
Has this happened to you?
Anonymous answer, no personal data.
Frequently asked questions
How much does it cost to repair this fault?
No verified estimate; ask the garage for a quote.
A rough figure from the original database, not an up-to-date quote.
Calculate estimateHow is it checked?
Ask the workshop to check whether code P056300 was stored with a voltage of 15.75 to 16.5 V and update the transmission software according to note LI27.19-P-080823.
What are the symptoms?
Transmission fault message, engine warning light on and the gearbox shifts into neutral (N); the fault disappears after switching off and restarting.
Which cars and years does it affect?
- Brands
- Mercedes-Benz
- Engine / equipment
- Mercedes-Benz A-Class (W177), CLA (118), GLA (247) and GLB (247) with the 8G-DCT dual-clutch transmission (724.1)
- Period mentioned
- 2021–2023 (US model years)
Which fault codes appear?
Taking it to a garage?
Models with this entry
- Mercedes-Benz Clase A (W177)2018–2026
- Mercedes-Benz CLA (C118) / GLA (H247) / GLB2019–2026
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