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Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53940
Experience:  Bosch Certified Master Tech. Over 35 years experience.
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I have a 2005 Mercedes c240 no start / no crank and I need

Customer Question

I have a 2005 Mercedes c240 no start / no crank and I need help with the diag. I have mercedes xentry scanner if need be, test light, DVM, etc.. Just need someone who is proficient in this cars electrical system.
Submitted: 1 year ago.
Category: Mercedes
Customer: replied 1 year ago.
FYI...Probably won't be working on the car till Saturday during the day
Expert:  Marty replied 1 year ago.

Hi, sorry for the wait I was away yesterday. The first thing you should do is test the starter directly at the solenoid and see if it works. You might just have a bad starter. Next step is to check fuse 52 and see if it's blown. If the fuse is good you will need to check the starer relay. If the relay is good you will need to check your actual values to see if you are getting a terminal 50 output to the relay.

Let me know what you find.


Customer: replied 1 year ago.
Hi Marty,
Thanks for answering. I actually started working on this car on Friday afternoon,which is when I posted the question. I guess everyone was on their way home for the weekend, so I did not get a response then. Here's where I left off on Friday: I checked the starter fuse, was good, I checked the relay and that is also good. I then turned the key to the "on" position, and grounded the starter relay at terminal 1, which pulled down the internal contact in the relay and sent power direct to the starter, and the engine began to crank. However, when I turn the key to the start position, I get nothing but a click. There is a brief history of what I checked, and where I am currently at with the car. Where would I go from here?
Expert:  Marty replied 1 year ago.

Possible causes are the gearshift is not reporting park position or there is a fault with the EIS or the ESL or the ECU. If the ECU does not get a park position signal from the TCU it will not authorize starting. If the EIS does not get an unlock signal from the ESL it will not authorize starting. You need to look at your actual values in the EIS and see if you are getting all of the necessary inputs to authorize starting.

Customer: replied 1 year ago.
Good response. I will check these items and get back to you. Also, is there any issues with water getting on pass floor causing electrical issues on this model?
Customer: replied 1 year ago.
if so i will check.
Expert:  Marty replied 1 year ago.

Anytime water gets into the car there is the possibility of it causing problems but there isn't anything on the passenger side that I can recall that would cause a no crank condition. If the gearshift electronics got wet it could cause the problem though.

Customer: replied 1 year ago.
I checked what you said, did not see any issues. Would you mind remoting in through teamviewer? I
Expert:  Marty replied 1 year ago.

I'm not going to be able to remote in to you. What did you show for actual values?

Customer: replied 1 year ago.
I have pictures of key on that show the values. Let me know what you think. As far as the selector lever goes, the gear position on the dashboard match the actual position of the gearshifter, which also matched the readout on the scanner.
Expert:  Marty replied 1 year ago.

Can you go into the EIS and look at the actual values when turning the key to the start position?

Customer: replied 1 year ago.
Sure, I will get back to you today with that. Thanks for sticking with me, I'm sure the solution is near.
Customer: replied 1 year ago.
OK here is the info you suggested I check. I see no change from key on position to start position. For circuit 50 output, according to the scanner there is none when I turn the key to the start position. Is that normal? I am looking at item 506 and 507 when turning the key to start, they do not change. Also possibly 503, when I turn to start I get a line through. Here are pictures of the values for start position. Let me know if anything strikes you as odd.
Customer: replied 1 year ago.
Just touching back with you to see if you had a chance to review my last reply.

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