Would a failing Crankshaft Position Sensor throw a fault code, that the MBII diagnostic system could see … if the engine started?

[Submariner1]

Every now and then instead of the perfect Single “VROOOM“ and it starts first time . I get a “rr rrr rVROOM” and it starts. Like it cranks over 2 or three times. Note it has never failed to actually start with one press of KLG.
This long start might be every 20 starts or 50 starts or a few months later.

This initially started happening about 3 days after service last December ( where they changed the fuel filter ).
Initially I thought they were sloppy and had let some dirt fall into the bowl-holder or something … note its located under the rear passenger un-moveable seat.

I have read when the CPS goes wrong it can often begin with very intermittent partial failures.
But running the MBII diagnostic .. gave no fault codes, ran the generic ODBC engine test as well , no fault codes.
any ideas?
would the proper Star system be able to see a CPS fault code? Or does the engine have to fail to start?

I have also heard that a poor battery can Cause starting issues. Any views?

History of Low Voltage:
I have now had battery issues for 4 years. Basically changed the original 95AH battery after 8 years … preventive maintenance LOL, as it would often read 12.5 or 12.6V.
The new one is only 92 AH …. Bad move by MB, and its an AGM battery … total shite!
Within a week the turnover sounded really weak. Note new battery delivered read 12.8V. After a weeks use it showed 12.8V after charge on CTEK charger and dropped to 12.5 V and lower very quickly within 10 mins, 2 further weeks on and it could NOT even start the car. Mobilo got another one FOC.

My quincesent battery drain is between 0.03 and 0.04 max. And more normally between 0.00 to 0.02 A. ( checked by Mobilo Tech ). Says up to 0.055 A drain is normal With all these extras.
This second battery is crap too, it can’t hold a charge.
Currently 4 years old and here is an example
I charged it up fully on Saturday with a CTEK (final reading 14.3V dropped to ‘maintain’ mode of 13.8V as it should; Disconnected the charger and 5 mins later it was at 12.6V, one more hour later it shows 12.5V.
Next day it reads 12.4V after the car has shut down.
2nd Day a very short 3 mile drive with stereo on.
3rd Day opened bonnet it reads 12.0V , with a current drain of 2.9A ; 2 mins later drain is 0.02A i.e. after the car shutdown, and the battery reads 12.2V!
IMO thats too low?
is this battery faulty?

Before I get the CPS changed I would ideally have liked to change the Battery again, but the price has gone from £126 to £156 @ Grangemouth delivered and £190 at local MB dealer.
…. and I suspect the next one will be defective,
MB won’t do anything because this one starts the car; but only because I charge it once every week or two. And now they say its more than 2 years so no replacement or goodwill gesture.
Or I could pay them to do the full Star check, for £160! (note the replaced one passed Star quick checks twice
, but failed the STAR deep test. That Found faulty connection between cells!).
So for me its better to let it fail totally, and pic a time when its not vital and simply not give it constant top up charges.
WTF its like having an Electric Car.

I wonder if MB have a 100AH or 105AH with the same dimensions? … its a very tight fit.

 

[mersum1es]

I think cps will not trigger a fault unless automated start fails. Or time window for waiting sync happen, is quite long anyway.
Iam not fully aware what gasoline engine requires for succesfull start, diesel has enough rpm, cps/css sync, rail pressure, fuel temp ...

 

[Doug1234]

I had the “rr rrr vroom” on my om642 for the last month or so and as you do you think bad battery … failing tank pump… failing high pressure pump… bad battery … alternator draining battery or some other kind of drain. Well one morning it lurched and then started and after that start no more.
Multi meter out and narrowed it down to starter motor solenoid not happy /not working so new starter motor time . £84 all done and did it from above removing engine mount and a couple of fuse boxes set to one side (Jeep Grand Cherokee).
Brushes were worn out in the motor ,two of them fell out as slivers and the other two were about 4mm thick.
The thing is it had been taking longer to start and since fixing it I have learnt the engine ecu will not fire injectors until 200 rpm is reached so I expect this is where the long crank time comes in.
This is also using klg auto start, I think the Jeep has a max of around 6 seconds before it stops if no start.

 

[mioba]

All sounds battery related to me Sub.

Was the original battery AGM, which have different charge / discharge cycles and thus alternator/car specific

 

[Submariner1]

I had the “rr rrr vroom” on my om642 for the last month or so and as you do you think bad battery … failing tank pump… failing high pressure pump… bad battery … alternator draining battery or some other kind of drain. Well one morning it lurched and then started and after that start no more.
Multi meter out and narrowed it down to starter motor solenoid not happy /not working so new starter motor time . £84 all done and did it from above removing engine mount and a couple of fuse boxes set to one side (Jeep Grand Cherokee).
Brushes were worn out in the motor ,two of them fell out as slivers and the other two were about 4mm thick.
The thing is it had been taking longer to start and since fixing it I have learnt the engine ecu will not fire injectors until 200 rpm is reached so I expect this is where the long crank time comes in.
This is also using klg auto start, I think the Jeep has a max of around 6 seconds before it stops if no start.

Interesting …
did you get this long start every-time?
I may get it once, and then not for 3 weeks say 20 to 50 starts later.
I don’t think I have ever got this just after a top up charge on the CTEK.

what mileage did you have?, I would hope a starter motor on a 5.5L S Class Coupe would do more than 51,000 miles; but then my brain is still tarnished with the Quality of Old Mercs like my mothers 300Se S class and my 2.6 190E, both just never had a single problem. Sorry I lie I did lose a glove box lightbulb in year 3.
those were the days eh!

 

[Submariner1]

All sounds battery related to me Sub.

Was the original battery AGM, which have different charge / discharge cycles and thus alternator/car specific

Hi Mioba
Not sure, only have a partial pic of it. Says VRLA, whereas the new one says VRLA - AGM Battery. If that helps

 

[Submariner1]

I think cps will not trigger a fault unless automated start fails. Or time window for waiting sync happen, is quite long anyway.
Iam not fully aware what gasoline engine requires for succesfull start, diesel has enough rpm, cps/css sync, rail pressure, fuel temp ...

Thanks

 

[Doug1234]

Interesting …
did you get this long start every-time?
I may get it once, and then not for 3 weeks say 20 to 50 starts later.
I don’t think I have ever got this just after a top up charge on the CTEK.

what mileage did you have?, I would hope a starter motor on a 5.5L S Class Coupe would do more than 51,000 miles; but then my brain is still tarnished with the Quality of Old Mercs like my mothers 300Se S class and my 2.6 190E, both just never had a single problem. Sorry I lie I did lose a glove box lightbulb in year 3.
those were the days eh!

I was getting the longer start off and on for about 3 weeks until the starter motor eventually died. Hot or part warm starts still had the same time duration to engine firing as well.
I was quite surprised by the size of the starter motor expecting a huge lump weighing around 4 kilos or so only to find a very small one that could be held with one hand and even its solenoid is nearly half the size of the actual motor, upon autopsy I found it had reduction gears inside so it spins fast to create more torque using the gears to get the job done.

 

[Submariner1]

I was getting the longer start off and on for about 3 weeks until the starter motor eventually died. Hot or part warm starts still had the same time duration to engine firing as well.
I was quite surprised by the size of the starter motor expecting a huge lump weighing around 4 kilos or so only to find a very small one that could be held with one hand and even its solenoid is nearly half the size of the actual motor, upon autopsy I found it had reduction gears inside so it spins fast to create more torque using the gears to get the job done.

Useful to know, but by “off and on“ …. I assume thats like every other, or third start was a long one. And totally failed within 3 weeks.
Whereas mine is more like every 20 or even 50 starts it goes into long mode, and has been doing it for a year.
Sound different but could be the same thing … at least useful to put on the list to rule out … or in?
Bet they are expensive

 

[Botus]

its not the battery its the car - as they age they all seem to need more help.

The big battery in the back doesn't like being left to its own devices for more than 2 weeks. It will easily take 24 hrs charge once a week (which is the same case on my fathers w211).. Both cars have been like this in the 8 years we had them.. And its exactly the same if an old battery or a new battery (he's on his third and so am I).

If I wait 3 weeks it will take a 4 amp charge for more than 48 hrs and still enjoy more. If your drive for 10 miles every two weeks you'll never know it really needs a better charge... you shouldn't disconnect the charger the idea it is plays with it and improves if left on.

The CPS gets worse with heat and it normally coughs dropping down to idle and maybe stalls and or won't start hot... it does show up on My Autel kit for the same engine you have

Mine starts off its original front battery, and always sounds and cranks the same.

Did you ever fix your clock using the update CD ? if not why not - yours was always on the list of supported units 2168209926 ?

 

[Submariner1]

its not the battery its the car - as they age they all seem to need more help.

The big battery in the back doesn't like being left to its own devices for more than 2 weeks. It will easily take 24 hrs charge once a week (which is the same case on my fathers w211).. Both cars have been like this in the 8 years we had them.. And its exactly the same if an old battery or a new battery (he's on his third and so am I).

If I wait 3 weeks it will take a 4 amp charge for more than 48 hrs and still enjoy more. If your drive for 10 miles every two weeks you'll never know it really needs a better charge... you shouldn't disconnect the charger the idea it is plays with it and improves if left on.

The CPS gets worse with heat and it normally coughs dropping down to idle and maybe stalls and or won't start hot... it does show up on My Autel kit for the same engine you have

Mine starts off its original front battery, and always sounds and cranks the same.

Did you ever fix your clock using the update CD ? if not why not - yours was always on the list of supported units 2168209926 ?

Thanks Botus,
Mine only has a single battery, well one big one and apparently a tiny one in the end of the dashboard.
But the ability to hold a charge and recharge sounds about the same.

Not convinced its the Car, if it shows 13.8V after going to care mode on the CTEK, but drops to 12.6V in 5 mins. That to me is its limit. Not sure how it drops to 12.0V in 72 hours if the Fluke says the battery drain is 0.02A. Er thats 1.44 AH out of a total 92AH.
I would have expected it to be around the 12.5V as a minimum

No I didn't resolve the Clock issue. When it was Serviced they said they didnt have time, but didnt seem to know how to cure it tbh.
So as it was accurate bar being 1 hour out , I just set it so the arrival time in Sat Nav was correct.
Now it seems even worse and the minutes are wrong and the hour on the Anolgue clock but OK for Sat Nav, and the Anolgue clock doesnt respond at all To any changes on the digitsl clock. Plus the date is bonkers like 2013 or something.

I think I will disconnect the battery for a few mins and see if the clock catches up.
Must get around to that, when it goes in for service 4th Jan is their first day available, due to Covid illnesses.
please remind me what is the “2168209926” number?

 

[Botus]

mine isn't much different don't forget its a 12v battery not a 14v - does keyless need extra juice to know when a keys close (I don't have that) ?

clock is 10 mins DIY after making a CD yourself. without it the car/clock is broken which is why the date is silly - but normal when you put the new software on so it knows how satellites now send info

its the actual MB number of your comand unit - its on the "original list" of supported units, rather than the two new ones we added so more owners can have it work correctly

Setting the date and time - W221 / C216

I don't understand why anyone would hope to burn a disc using windows built in software.... (clunky nasty and often less than 50% success rate in it actually trying to write the files and then a 25% rate the disc is actually usable). they repeatedly demonstrate since circa 2004 they have...

forums.mercedesclub.org.uk

 

[Submariner1]

mine isn't much different don't forget its a 12v battery not a 14v - does keyless need extra juice to know when a keys close (I don't have that) ?

clock is 10 mins DIY after making a CD yourself. without it the car/clock is broken which is why the date is silly - but normal when you put the new software on so it knows how satellites now send info

its the actual MB number of your comand unit - its on the "original list" of supported units, rather than the two new ones we added so more owners can have it work correctly

Setting the date and time - W221 / C216

I don't understand why anyone would hope to burn a disc using windows built in software.... (clunky nasty and often less than 50% success rate in it actually trying to write the files and then a 25% rate the disc is actually usable). they repeatedly demonstrate since circa 2004 they have...

forums.mercedesclub.org.uk

Hi Botus
thanks for the detailed reply much appreciated.
Yes keyless does use a tiny bit more, and even then CL can take up to 4 mins to fully ”shutdown” if you turn off Comand, and AC, ILS to 0, lock doors and boot, and push both bonnet locks shut. If you dont use this process can take up to 9 mins

Got to admit my knowledge of PCs burning discs is useless, and I am really scared I could burn a faulty disc and end up with a truly broken Comand system.
I asked the MB Dealer how much , he said my car did not show any Updates were available, But the process needed was ro put it onto STAR and then that would tell them what was needed and could take 4 to 9 hrs for the process to complete!
He said if they had a number of cars updating then it takes longer as their broadband band width was shared. And it had an “initial” cost of £148, but could cost more dependant on what STAR said needed doing. Hmmm I don't like the word initial!
But a 4 hour session makes this difficult, as ai am driving from Berks to Guildford as it is! And if it turned into a 6 hour update plus the time for service … means an overnighter. Not really practical.
Sadly Vertu has now bought the last remaining MB dealership near me … vicious pricing .. the Customer is really paying for that takeover!
so I might have to risk the burning disc route.
I did find the thread “Setting the date and time - W221 / C216” which explains the process. Will have to scrutinise that in detail.
Questions like does my car have another single CD reader, just for the SAT Nav? In addition to the 6 stack in the console? Etc.

They did do one update on Comand before and the screen slightly changed, looked a bit more modern, especially noticable when you came up to a junction on a motorway, it split the screen to show the turn off. Is thats whats called the “Birdseye update”.?

ATM … got a bunch of possible CL issues.
1. Does it need another new battery …. All this charging palava, really has soured the CL experience.
2. Does it need a new Crank Position Sensor or is it the battery
3. Does it need the Heater Changeover Valve replacing
4. Should I change the Coolant as it looks a little lighter in colour than a true 50/50 mix.
5. Rear window issue, the SAM overright fix by Beaconsfield partially failed again to needs 3 presses of the window to close. I am pretty sure when they “repositioned the rear window” its too tight.
Hmmm £ Happy Christmas.

regards Peter

 

[Botus]

never go to a dealer and ask about software updates, they have NO clue how to change the oil, let alone do complex jobs well

the car isn't stupid make a bad disc it will check its contents and say bugger off and just do nothing - as for the appalling mess that is Merc softwafe updates, highly likely it doesn't say comand is out of date apply this. Its so up itself, it often says I don't know whats going on but it must be out of date - when it isn't, and the other half of the time says its up to date - when it isn't). I'm getting quite frustrated anyone thinks there are people left that know what they are doing, all the good people were sacked and we just have dregs of humanity on slave pay messing it up till the sun turns off

In the meantime - a disc was created to DIY, and it just tells the clock how to behave (it impacts the built in service schedules so might as well be right rather than muddled) - merc took it on board BUT its wrong, a check for supported head units before programming forgot two units and just doesn't load the update on those cars. I took a look in the last few weeks and saw a likely driver - so I re did a few simple bits of the disc and now it does a bunch of mid 2007 to 2008 comand units Merc forgot it needs to update.

The post I linked to has
The wrong official Merc disc on post 49

Setting the date and time - W221 / C216

hey.... if you read the instructions. It says the pic below is NOT in the right view for the update to run must have the focus on the Comand Menu (far left) worth seeing if you had that right ? MAKE SURE “COMAND” IS SELECTED ON THE TOP MENU, now using the Comand knob, pull it toward you to...

forums.mercedesclub.org.uk

And my correct disc on post 80

Setting the date and time - W221 / C216

I have tried to edit the iso file but no luck. I can change the 391 to 392 but it won't save the change

forums.mercedesclub.org.uk

Don't ever expect Merc to notice let alone resolve what they did wrong either...

here's the official PDF 11 Jan 2020 stating the need for a software update
(even here its incorrect "after the update its possible to set the time and date" WRONG!!! After the update the car will be able to work in the current epoch and process the satellite info correctly for another 19 years, AUTOMATICALLY updating the time and date. This later document came after the joke you have previously read, describing a pointless zero chance of making a difference fix, they claimed worked from 20 March 2019

the gist is garage you use can't even read, let alone put a CD in the car - FYI you can use either disc as your unit was always supported

 

[LostKiwi]

"

Would a failing Crankshaft Position Sensor throw a fault code, that the MBII diagnostic system could see … if the engine started?"​

Yes.

 

[Wearsafoxhat]

My MB 2 picked up my failing cps as a stored code.
Had a slow start and engine light on for a outbound journey, but the car was fine on the return trip. The next day I used my MB2 and it was stored..

then discovered that the bolt had been rounded off on the cps which took a few days to resolve.


Sent from my iPad using Tapatalk

 

[Botus]

just found these on Batteries - bit disappointing really

Winter battery maintenance advice for motorists

Part of a technician’s skill is to prevent a customer’s vehicle from breaking down in the first place. In the case of cold weather, flat batteries are the greatest danger, but to prevent this from hap

pmmonline.co.uk

Rotronics offers battery advice

Batt Rotronics is one of the UK’s leading battery management specialists, and therefore Managing Director Ken Clark is best placed to provide excellent battery advice for PMM readers. Here, he highlig

pmmonline.co.uk

The complex process behind batteries

ECOBAT charts the complex process behind the modern car battery and seeks to clear up any remaining confusion. In terms of the aftermarket, batteries have historically been a relatively simple compone

pmmonline.co.uk

 

[Submariner1]

"

Would a failing Crankshaft Position Sensor throw a fault code, that the MBII diagnostic system could see … if the engine started?"​

Yes.

Thank you LostKiwi,
I ran a scan with My MBII on the ODBII section and got no faults found, other than an Historic Lumbar support fail.


Then did a Global Scan and an Individual test on all the categories with the engine in them. No fault found.

Then I looked at the REVIEW results and found two reviews ( no date to help one). So assumed they were the results from the latest global scan?
The manual is useless, so not really sure how one uses this tool.

The review of Benz.EN found no faults

But the ODB.En Review
found 2 faults


What is a serial communication link?


So I am totally confused, at first the full ODBII test says OK, the Individual tests say OK, running the Global scan and looking at each catergory says No fault.
But Under this “Review” box it says a “Pending” error code.
what does Pending mean?
And does this mean that I should replace it?

 

[Botus]

I presume pending is still there (pending a fix ???)

you'd hope OBD2 ought to pick up CPS as its a standard designed to assist in identifying emission specific engine issues

OBD2 diagnostics not be be confused with anything really helpful - the law is they must display 6 parameters that might give a clue when its being odd / won't run if its going to impact emission control

Whereas manu specific diagnostics can be anywhere between not much better, or the full monty telling you everything about the car (which is where Merc and BM land things)

If I were you I would NEVER bother with an OBD2 scan on a Merc or BMW it will confuse, mislead or add ZERO value at all - jump in to a full manu scan of everything on the car - that your tool supports - if its budget OBD2 only - don't even plug it in

 

[Submariner1]

I presume pending is still there (pending a fix ???)

you'd hope OBD2 ought to pick up CPS as its a standard designed to assist in identifying emission specific engine issues

OBD2 diagnostics not be be confused with anything really helpful - the law is they must display 6 parameters than might give a clue when its being odd / won't run if its going to impact emission control

Whereas manu specific diagnostics can be anywhere between not much better, or the full monty telling you everything about the car (which is where Merc and BM land things)

If I were you I would NEVER bother with an OBD2 scan on a Merc or BMW its will confuse, mislead or add ZERO value at all

Thanks, thats why I would have expected the Mercedes specific tests to show an error code on the engine tests, before the general scan.