Datsun_76

Need some advice on where I should start troubleshooting.

I have a 2006 CLS55 AMG. It is currently -10 F outside and my car does not want to start. It will crank but not turn over. My battery voltage is a bit low at 11.9 volts when the car is off. If I can get it to finally turn over (most days it won't start when it's this cold) the voltage is 13.9 and I get the "low battery conven functions temporarily unavailable" error for a few minutes. The car only has this issue when the temperature is below 15 F. Anything warmer than 15 F and it starts beautifully.

I replaced my alternator, crank position sensor, starter, and both batteries over the summer. I have had both batteries tested multiple times at different places and they are good.

I am not sure where to start troubleshooting from here. I do not think it is fuel-related. I have good pressure at the rails.

I posted this on the W219 forum but was wondering if anyone with a w211 has had a similar issue or some insight.

Any suggestions/input would be appreciated. Thanks!

machild

Do you have anyway to have a MB DAS diagnostic scan on the car to see if any faults have been set for this issue?

Datsun_76

I have an iCarsoft MBII scan tool that can read the MB modules. It can go into most CAN modules (TCM, SBC, ECM, SAM ect...) I have gone through the ECM modules and did not see anything. I haven't gone through all the modules yet. What modules should I be looking at?

machild

I think you need a full scan of the entire car. With the MB DAS it does a full scan of each module. If the MBII has a similar function that would be what you want. As you have noted, MBII may not have access to each module so if there is an issue in a module not scanned you don't have what you need. If you have access to DAS that would be the best tool to use. I don't know specifics on MBII, but I know some scanners that supposedly work with MB cars can report non-existing faults and miss actual faults.

SICAMG

You say it cranks but does not turn over. do you mean the starter engages , spins the engine and it will not start and run?

Datsun_76

Yup the engine will crank but will not turn over. The starter engages fine but it will not come to life.

machild

Sounds like ice in the fuel lines.

SICAMG

Just so your wording is understood by others, cranking means turning over. Starting means it will or will not run on it's own. So engine turns over but doe's not start.
So with that being said see if you have spark and fuel. Pull a plug after trying to start it and it should have fuel on it if there is no spark.
Ground the plug connected to the spark plug wire and you should see a spark every time it fires on that plug. This will take two people to make it easy.