Non Start & Start Stop Issues/Command Unit

[j.taylor2299]

Hello

I am having issues with my W205 C Class 2.2 Diesel.

Around 6 months ago, I got the error stop car and keep engine running, so I bought a new battery.

Problems solved and even the start stop starting working for a few days then stopped (start stop never worked since I’ve had the car)

Now I’m getting issues starting, sometimes when I go to start it, it will crank over, then stop, it will do this several times but will eventually start.
Other times it starts no problem,

When it does the starting issues, I get all errors like abs, traction control etc, but a little rev and it goes away. Also the radio/command unit goes off, and won’t turn on again for a few minutes.

I have just replaced the auxiliary battery thinking this may be the problem but nothing has changed with that.

I have tested the main battery with a tester and seems to be holding a charge, multi meter tests show 12.7 normal with 13.8 with engine running.

So I am struggling now and not sure what to do next? Maybe alternator?

Any help would be appreciated
Thanks

 

[malcolm E53 AMG]

Which battery manufacturer?

You can check the alternator by using the multimeter when the engine is running it should be around 14.8V

 

[j.taylor2299]

Which battery manufacturer?

You can check the alternator by using the multimeter when the engine is running it should be around 14.8V

Pretty sure it’s a Lucas Battery,

And I’ve tested it while running and I’m getting 13.7v/13.8v, even when I loaded it with lights, blowers,heaters etc, it still read 13.8v

No where near 14.8v

 

[Chrishazle]

Wonder if your 205 C220 has the facility of my 204 C220 with NTG4 - namely key at position 1, press answer call - end call - OK simultaneously and hold for about 5 seconds and get a menu in the centre of the dashboard that says something like "vehicle details" at the top - press OK (should say all buttoms mentioned are on the steering wheel) and the display shows battery voltage and amps useage. Start the car and the display now shows alternator output and amps either leaving or going back to the battery. Stays like that until you either press the back button on the steering wheel or switch the engine off. I find this facility so useful as we do not use the car much, I have a Lidl battery condition monitor attached to the battery and visible through the tailgate (S204 estate), if I have red and orange car will start, sometime a bit sluggishly, but if just red I need to put the charger on it.

 

[malcolm E53 AMG]

Pretty sure it’s a Lucas Battery,

And I’ve tested it while running and I’m getting 13.7v/13.8v, even when I loaded it with lights, blowers,heaters etc, it still read 13.8v

No where near 14.8v

Fully loaded I’d expect the alternator to be charging around 14.5V

I only use Varta or Bosch batteries any chance you can try another battery?

 

[brandwooddixon]

Looks to me as if it's suffering a voltage drop on cranking.
Is the battery the correct spec. for cranking amps?
What does the battery read when not loaded?
Check resistance between battery negative terminal and engine, it should be pretty low.

 

[j.taylor2299]

Looks to me as if it's suffering a voltage drop on cranking.
Is the battery the correct spec. for cranking amps?
What does the battery read when not loaded?
Check resistance between battery negative terminal and engine, it should be pretty low.

Battery is the same amp as what was taken out, which was OG merc/bosch battery
Sure it as 990 or something around there, would need to double check though

Battery reading 13.7v on idle, and 12.7 which engine switched off

 

[j.taylor2299]

Fully loaded I’d expect the alternator to be charging around 14.5V

I only use Varta or Bosch batteries any chance you can try another battery?

I’m temped to buy a new battery from merc but they aren’t cheap, even the Lucas one was £200

I though it should be charging around 14.4 also, would you suspect alternator in this case?

 

[j.taylor2299]

Wonder if your 205 C220 has the facility of my 204 C220 with NTG4 - namely key at position 1, press answer call - end call - OK simultaneously and hold for about 5 seconds and get a menu in the centre of the dashboard that says something like "vehicle details" at the top - press OK (should say all buttoms mentioned are on the steering wheel) and the display shows battery voltage and amps useage. Start the car and the display now shows alternator output and amps either leaving or going back to the battery. Stays like that until you either press the back button on the steering wheel or switch the engine off. I find this facility so useful as we do not use the car much, I have a Lidl battery condition monitor attached to the battery and visible through the tailgate (S204 estate), if I have red and orange car will start, sometime a bit sluggishly, but if just red I need to put the charger on it.

This is my screen if it makes any sense to you?

After driving for a wee bit, the voltage was around 13.5v and amps went down to 2.1A

 

[malcolm E53 AMG]

A lot on here use https://www.tayna.co.uk/ including myself I think your new battery is suffering a voltage drop due to an internal fault.
Tayna are my go to supplier usually next day delivery OEM are Varta or Bosch but before spending more money on a new battery it might be a good idea to take it to a garage than can do a voltage drop test

 

[AlanGunn]

+1 on Tayna good prices and spot on service.
They are not that far from me and i have been to them with problems like this and they do all sorts of testing at no cost very helpful bunch there.

 

[brandwooddixon]

Battery is the same amp as what was taken out, which was OG merc/bosch battery
Sure it as 990 or something around there, would need to double check though

Battery reading 13.7v on idle, and 12.7 which engine switched off

Those voltages are low, when running I'd expect at least 14V from the alternator.
I still think that there's a voltage dip when starting.
Is the new battery the same composition as the original e.g., AGM? This can have an effect. For example I have a booster pack that will give 1500 cranking amps and yet wouldn't turn over my old car engine as the peak was supplied for too short a period and yet a different pack using different battery technology but the same output could.

I'd check that that the earth strap is giving a good connection. Test by adding a new connection between engine and battery negative terminal (one jump lead), then check if starting behaviour and running voltage improves.

If no joy then check starting behaviour using jump leads to another car. If all looks okay then I'd suspect a battery issue.

 

[j.taylor2299]

Those voltages are low, when running I'd expect at least 14V from the alternator.
I still think that there's a voltage dip when starting.
Is the new battery the same composition as the original e.g., AGM? This can have an effect. For example I have a booster pack that will give 1500 cranking amps and yet wouldn't turn over my old car engine as the peak was supplied for too short a period and yet a different pack using different battery technology but the same output could.

I'd check that that the earth strap is giving a good connection. Test by adding a new connection between engine and battery negative terminal (one jump lead), then check if starting behaviour and running voltage improves.

If no joy then check starting behaviour using jump leads to another car. If all looks okay then I'd suspect a battery issue.

So today I went out a bought a new battery, the one I bought was Bosch S5 at £228 from my local parts supplier.

Went a road test, everything seem good untill I stopped, then tried to restart the car, again the same problem
Voltage when driving is around 13.7v and amps went down to as low as 1.2A

When I sit idle for a few minutes, voltage goes up to 14.0v but never any higher


I will try the test with the negative & jump leads to see if that improves anything

 

[j.taylor2299]

Update

I’ve just tried a jump leads for the negative and charging voltage has jumped up to 14.6V, where it should be,

I’m assuming this will be an earth fault?

Could it be the earth cable from battery to body, the one with the battery sensor on it, as it looks a wee bit corroded on closer inspection

 

[brandwooddixon]

Update

I’ve just tried a jump leads for the negative and charging voltage has jumped up to 14.6V, where it should be,

I’m assuming this will be an earth fault?

Could it be the earth cable from battery to body, the one with the battery sensor on it, as it looks a wee bit corroded on closer inspection

Sounds like an earth fault.
Try starting the car with that jump lead attached between the engine and battery negative.

 

[j.taylor2299]

Sounds like an earth fault.
Try starting the car with that jump lead attached between the engine and battery negative.

Ive done this and the voltage shot up too 14.6v instantly

 

[brandwooddixon]

There will be several earth straps.
There's the obvious battery to body connection, but there should also be body to engine & gearbox. I don't know where they are on your car, but they tend to be low down on the car and are often bare braided copper, but due to location often corrode. They're not usually very expensive.

A visit to a friendly MB dealership should sort things out pretty quickly and they'll be able to show you where on the car they are. I guess that Coldstream or Edinburgh are your closest.

 

[j.taylor2299]

There will be several earth straps.
There's the obvious battery to body connection, but there should also be body to engine & gearbox. I don't know where they are on your car, but they tend to be low down on the car and are often bare braided copper, but due to location often corrode. They're not usually very expensive.

A visit to a friendly MB dealership should sort things out pretty quickly and they'll be able to show you where on the car they are. I guess that Coldstream or Edinburgh are your closest.

The one from the battery to the body looks corroded so il try cleaning that one first
Then if not il look into the rest.

I’ve got my car booked in at Mercedes in Edinburgh today for a MOT so might ask when I pick it up

 

[j.taylor2299]

Update - Fixed!!

Today I removed the battery, and then the negative battery lead that runs from battery to the body, turns out it was very corroded!

I cleaned it all up on the wire wheel, put it all back into place and back to running 14.7 volts

Looks like there has been water sitting around there for a while and it’s corroded, but looks like the scuttle panel drains down to under the battery

But glad it’s fixed

 

[j.taylor2299]

Thanks for all your help guys