KNOWN FAULTS · Mercedes-Benz

Mercedes-Benz GLC (X254) GLC 300 e / 400 e common problems.

2022–2026 · Plug-in hybrid

Sources are not verified in real time and no entry confirms that your car is affected.

2 known faults with sources

Applies if: Only if fitted with the automatic gearbox described in the record.

9G-Tronic harsh shiftingAutomatic gearbox

Engine / equipment: 9G-Tronic automatic gearbox (725.0 and 725.1): C-Class W205 and W206, E W212 and W213, CLS, S W222 and W223, GLC, GLE, GLS, SL and SLC
Period mentioned: 2013–2026
Symptoms: Harsh or jerky shifts (especially 1st to 2nd and when cold), vibration, delayed shifts or limp mode; sometimes the gear will not engage from N to D. Codes P073E00 and P07B700.
Possible cause described: Mercedes acknowledges in a technical bulletin complaints of harsh shifts, shudder and limp mode with various causes. In the early years (2014–2016) it is usually software or adaptation rather than mechanical damage; in other cases the pressure sensor built into the gearbox control unit fails.
Check for the garage: Follow the Mercedes bulletin: reproduce the complaint, save the EEPROM, check the oil level, run the Xentry valve flush, update engine, gearbox and shift unit software and perform the standstill adaptation. If it persists, check the control unit.
Cost cited in the source: Software update and adaptation: the most common and cheapest fix; repairing or replacing the control unit costs considerably more (the sources give no comparable figures)A rough figure from the original database, not an up-to-date quote.

Applies if: Same M254 engine with ISG as the C-Class W206; ask the dealer whether your engine has had the fix.

Camshaft adjusters on the M254 petrol engineValve timing

Engine / equipment: 1.5 and 2.0 four-cylinder M254 petrol with 48 V integrated starter-generator (ISG): C-Class W206, GLC X254, E-Class W214 and CLE
Period mentioned: 2021–2025 (mainly 2021–2022)
Symptoms: Rattling on start-up, the engine warning light and camshaft-timing fault codes; in serious cases, engine damage.
Possible cause described: A German used-car guide flags the M254 camshaft adjusters as something to check up to model year 2025; according to Motor-Talk users, a breaking oil strainer causes the damage, mainly on 2021 and 2022 cars. From 2025 no problems are reported.
Check for the garage: Listen to a cold start; read the engine fault memory; ask for the service history with on-time oil changes and ask the dealer what fix exists for the adjusters.
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.