Mercedes-Benz C Class Recall R/2021/241: Diodes On The Rectifier Bridge Of The Alternator Might Fail, Who Is Affected And What To Do
- Low
- How serious
- 27 Jul 2021
- Launched
- 18,050
- vehicles in the UK
- SRPC2044
- Manufacturer’s campaign code
Mercedes-Benz recalled C Class vehicles built between 20 March 2014 and 28 February 2018. Diodes on the rectifier bridge of the alternator might fail. The dealer will update the engine control unit software with an optimised alternator control strategy on the affected vehicles. You won't usually pay for it.1
What’s Wrong
Diodes on the rectifier bridge of the alternator might fail.
DVSA's Original Wording
Concern: DIODES ON THE RECTIFIER BRIDGE OF THE ALTERNATOR MIGHT FAIL Defect: Diodes on the rectifier bridge of the alternator might fail. Remedy: Update the engine control unit software with an optimised alternator control strategy on the affected vehicles.
Contains public sector information licensed under the Open Government Licence v3.0.
The Risk
The recall notice describes the concern as: diodes on the rectifier bridge of the alternator might fail.
The Fix
The dealer will update the engine control unit software with an optimised alternator control strategy on the affected vehicles. The fix is a software update, which usually takes under an hour at the dealer.
Are You Affected?
C Class built between 20 March 2014 and 28 February 2018 may be included. Mercedes-Benz estimates 18,050 vehicles in the UK. Enter your registration to check, then confirm by VIN with Mercedes-Benz, because not every car in the date range may be included.
Which Car Is It?
Choose the make and model so we can match recalls to your car.
What To Do Now
- Check your car by registration above, then by VIN with Mercedes-Benz.
- Book with any franchised Mercedes-Benz dealer, quoting the campaign code SRPC2044 or the DVSA reference R/2021/241. See how to get a Mercedes-Benz recall fixed.
- Follow the letter's instructions until the repair is done. See can you drive a car with a recall?.
Related Recalls
| Launched | Vehicle and fault | Severity | Reference |
|---|---|---|---|
| C Class, EQE, GLCBolting of steering coupling | Urgent | R/2025/333 | |
| C ClassDriver seat belt fitting | Urgent | R/2025/158 | |
| C Class, CLS, E Class, GLCMisfire detection M264 | Low | R/2024/474 | |
| C ClassBolting connection Pre-Fuse box | Low | R/2024/281 | |
| C ClassScrew connections of 12 V and 48 V ground points | Urgent | R/2024/299 |
This is one of 833 Mercedes-Benz recalls in DVSA’s data. The Mercedes-Benz recall launched before it was R/2021/264 on 21 Jul 2021, for the corrosion protection of the high voltage battery housing may not be ensured over…. The one launched after it was R/2021/255 on 6 Aug 2021, for one or more of the rear wheel speed sensors may experience an electrical failure. You can also see every Mercedes-Benz recall, the Mercedes-Benz C Class recall history and all recalls launched in 2021.
Source: DVSA recall R/2021/241, launched 27 July 2021. Data updated 15 October 2026. How we grade urgency.
Sources
- The Code does not itself say repairs are free. GOV.UK guidance says "You will not usually have to pay for any repairs or parts under a safety recall." gov.uk Checked 15 Oct 2026.