Engine cranks for less than 1 second & wont start

[Gixer800]

Hello to you all!

I have been following your fantastic forum for some time now but never joined up.

I have now brought myself an accident damaged 2nd Generation 2008 Clubman Cooper S 2008 manual, The damage was very light and did not activate airbags or any warning lights.

When i collected the car it started fine and was able to drive it on to the car trailer under its own power even with a broken off side engine mount.

I got the car home disconected the battery, unplugged the DME (ECU as i know it) and removed all broken parts, fan housing, bumper and brace, bonnet, etc... Rebuilt the car, refitted the DME and reconneted the battery.

I tried to start the car using the button and it sends a pulse to the starter for a split second - turning the starter very slightly only.

Replaced the battery for exact replacement (New) = Same thing!
Changed the starter (New) = Same thing
Checked the off side engine earth strap = same thing

Bump started the car = Works fine and runs great!!! but wont restart on key!
Checked all known fuses = All ok
I have found that if I string a wire from the positive to the solonide wire connector positioned on the off side bulk head = it turns over fine! if i then get someone to press the clutch and the start button followed by me touching my patch wire the car then starts - but ONLY by using this comination of start button AND patch wire.

PLEASE any ideas .

Kind regards,

Gixer800

[Gixer800]

Come on you guys and girls there must be a techy genius amongst you all that knows what it could be or what wire connection could be to blame.

I would really appereciate your help as I cannot use the car at all untill it's running.

[Gixer800]

Come on you lot!

Someone must have an idea, i have now had to resort to installing a second hidden switch which sends 12v directly from the battery to the starter solonoid.

I have to still press the normal start switch button to get things powered up then press the hidden switch to start the engine!

This must be a simple fix.

PLEEEEEEEEEEEEASE HELP uzz led:: puzzled:uzzl ed: uzzled:uzzle d:u zzled:uzzled : Doh!

[Gixer800]

Hello to you all,

I still need to find the cause of this problem, I'm loathed to take it into BMW as the costs are bloody day light robbery and they just seam to guess at my expense.

If you have any ideas please reply.

Thanks, Darren.

[stead34]

I'm not familiar with how mini control the starter, but this is done normally done on modern multiplexed vehicles by a mixture of information from the can-bus circuit and hard wired circuit and control ecu's. This is a brief description that may be the route they choose so you have a better idea, when the key is installed it will check the transponder code from the key,to the main vehicle interface and engine ecu if these sync up it will then unlock the ecu's, awaiting the command to start, the ecu's talk to each other via a can-bus network(data network) the Clutch switch info(may be hard wired to interface) will be sent on this and the starter button command also. If the main interface sees all the information needed(mention prev) then it will tell a fuse box in the engine bay via the can-bus line to send the 12v switch feed to the starter solenoid. So the electrics are to complicated to test without a diag machine as this can read what info is sent down can-bus network. At a guess I would say it is the ecu/fusebox that sends the switch feed to the solenoid as the ecu's are unlocking so immobiliser is ok,the clutch switch is ok,engine earth is ok,starter switch unsure(need diag to check). The components are expensive so a visit to a good auto electrician or mini dealership my actually save you money on this....

[stead34]

If you have a test light and a multimeter you could test the hard wiring under the bonnet. Carry out a voltage drop test from the battery earth terminal to the starter casing, carry out the same test between the positive battery terminal to the main feed on the solenoid this will be done when the circuit is is closed and current flowing, so disable the engine so it won't start, activate the starter by using a fly lead and using the multimeter on volts you should have a maximum reading of 0.5v but as the cable is so short it should read next to nothing..if this is ok then you have proven the main leads are good and engine earth. Then test the switch feed with the test lamp,disconnect the lead from the solenoid and make a lighting circuit with the test lamp, when the start button is pressed it should light up the lamp to the same brightness as if put across the battery terminals, if not there is a voltage drop(that's if you can get it to send a feed down). Find the other end of the starter switch feed and disconnect it and carry out resistance test to earth and positive to see if there are any short circuits in the cable. Make sure the battery is fully charged to carry out the live tests. If you have already done these tests or need a better description just post the results or concerns. As this is a crash damage vehicle this takes away the common known faults scenario and it's back to basics of testing and diagnosing from results found....

[Gixer800]

Hello Stead 34,
Many thanks for your in depth detailed reply, I have been away for a few weeks so have only recently seen your replies. I have tried and tested all of your ideas, The reading from the power to starter solinoid is only 0.5v and only for half a second.

Just to note, the car started properly even after the crash. It was not until I removed the battery and DME during the rebuild that the problem started.

I now drive the car daily using a patch lead taken from the positive terminal of battery to the starter solinoid via a rocker switch and diode to stop current flowing back to the electronics.

I still have to press the normal starter button followed by the new rocker switch to start the car.

Also i note that the car does not restart its self when using the 'STOP START' fascility.

Any other ideas gratefully recieved.

[saint2000]

Do you have both key fobs and do you get the same response using either one? sounds to me like an immobiliser issue.. have you got any OBDII diag tools? you can pick them up from around £30 to check for obvious faults & error codes... I'm looking at getting hold of some BMW software much like the VCDS for VW, just shopping around at the moment, but for faults like this it would be a breeze

[stead34]

The immobiliser would stop the engine starting,if the dme is locked(immobilised)then the injectors wouldnt even operate or the coil pack..it immobilises more than just the starter motor..

As you have tested the hard wiring,and its ok.. then the fault most likely in the ecu or fuse box, what ever controls the 12v trigger for the solenoid.. cant find a wiring diagram on the net to be more specific.

make sure no pins are bent on the dme, and that no connectors spread open causing voltage drop.

You have to find where the trigger supply to the solenoid comes from, just pop into mini and have a chat with one of there techs.

[Gixer800]

Hello guys,

Yes I do have both keys and they both have the same results as listed above.
I do have and tried my small obd fault tool (bought for £90) did not show any thing up on car.
I have also had a very good friend check it with a 'LAUNCH X431' £3000 system which cleared many basic faults within the '14' on board moduals!!!!

The only thing it could find with the starting system was error on 'Connector 50' which as far as I can tell is the low power 12v supply connector on the starter solonoid.

There is nothing wrong with it as I have also bought and replaced the complete starter and solonoid just incase - Made no difference.

[Gixer800]

Hello to you all!

I still have this same problem with the car and took it in to BMW yesterday to have the EWS and DME completely reprogrammed and aligned so all random code sequencies are now back in sequence.

Alas this has still not fixed the problem - they say it could be a fault with the CAS unit, sounds to me like they just guess at my expence!

Any ideas or anyone had the same problem?

Just to note it is nothing to do with the clutch pedal sensor as stated in my first post.