Mercedes-Benz Alternator Replacement V6 M272 - V8 M273

Contents

In this guide, you will learn how to replace the Alternator on a Mercedes E C CLK S ML GL R Class with the M272 and M273 engines. 

Symptoms

  • Battery warning light stay
  • Engine stalls.

What you will need

Parts

Tools

Procedure

  1. Park vehicle on level ground and set the parking brakes.
  2. Allow the engine to cool down.
  3. Pull the hood release under the dashboard and open the hood.
  4. Disconnect the battery. 
  5. Create a diagram of how the serpentine belt is routed on the different pulleys.releaseTensioner

     

  6. Loosen the serpentine belt by using a 17mm socket to twist the tensioner bolt counterclockwise.Mercedes tensioner releaseSlide the belt off it.remove serpentine belt from alternatorremoveGround

     

  7. Remove the alternator ground wire using a 12mm socket. Alternator positive connection cableremoveAlternatorbolts

     

  8. Loosen four (4) alternator retaining bolts using an E12 socket.removealternatorsocket

     

  9. Unplug the alternator electrical connector from the back of the alternator. Disconnect alternator connector mercedes benz r-class ml-class e-class

     

  10. Remove the alternator.
  11. Position the replacement alternator.
  12. Connect the alternator positive cable and electrical connector.
  13. Connect the negative connector using a 12mm socket. Re-attach the rubber cap(if any).Alternator positive connection cable
  14. Mount the alternator using 4 retaining bolts. Alternator Mercedes-Benz

     

  15. Twist the tensioner bolt counterclockwise and reposition the serpentine belt.
  16. Reconnect the battery.

Frequently Asked Question

How do you know your alternator is bad?

  • A common symptom of a defective alternator is when your battery light is on while the engine is running.

Can you drive a Mercedes with a faulty alternator?

  • It is not recommended to drive the car once the check battery light is on since it is more likely that the car would stall after a few minutes.

Applications

Mercedes-Benz vehicles equipped with an M273 engine.

M272 engine

  • 2004–2011 R171 SLK 350
  • M272 IN SLK R171.jpg
  • 2004–2010 W219 CLS 350
  • 2005–2010 C209 CLK 350
  • 2005–2007 W203 C 350
  • 2007–2011 W204 C 350 / C 350 4Matic
  • 2011–2015 W204 C 350 BlueEfficiency / C 350 4MATIC BlueEfficiency
  • 2005–2009 W211 E 350 / E 350 4MATIC
  • 2009–2011 W212 E 350 / E 350 4MATIC
  • 2005–2013 W221 S 350
  • 2005–2012 R230 SL 350
  • 2006–2017 W251 R 350
  • 2006–2011 W164 ML 350
  • 2005–2014 W639 Viano (known as the M272 978 in China)
  • 2006–2013 NCV3 Sprinter
  • 2008–2011 CL203 CLC 350
  • 2008–2012 X204 GLK 350

M273 engine

  • 2006–2011 E 500 / E 550
  • 2006–2010 CL 500 / CL 550
  • 2006–2010 CLS 500 / CLS 550
  • 2006–2012 GL 500 / GL 550
  • 2008–2011 ML 500 / ML 550
  • 2006–2009 S 500 / S 550
  • 2007–2012 SL 500 / SL 550
  • 2006–2009 CLK 500 / CLK 550
  • 2006-2015 G 500 / G 550
  • 2007–2012 GL 450
  • 2007–2013 S 450
  • 2007–2011 ML 450

 

DIY Cost: $100-$250
Est. Time: 2 hr
Difficulty: Intermediate
Mercedes-Benz Alternator Replacement V6 M272 - V8 M273 In this guide, you will learn how to replace the Alternator on a Mercedes E C CLK S ML GL R Class with the M272 and M273 engines.  Symptoms Battery warning light stay Engine stalls. What you will need Parts