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Mercedes Sprinter 2002 sprintshift 2.7 CDI - Non start unless you disconnect battery - Fixed #

Posted by Peter Holland on January 15, 2014, 4:35 pm

Year of Manufacture *: 2002
Engine Size and Code *: 2700
( Optional ) Scanner Used: Various!

This is a Hymer camper van which is proving to be difficult to identify accurately as they change the chassis number. It appears to be a 316 chassis. Anyway, it doesn't start unless you disconnect the battery and reconnect it with the ignition on. Otherwise the dash displays a start error fault. I can't talk to the gearbox ECU and am having problems talking to the engine ECU, immobiliser etc. It will only communicate when I get the engine started using the above method. I suspect a possible gearbox ECU but I can't locate it! Can anyone point me in the right direction? I was going to start off by disconnecting it and see if I can then comms with the other ECUs on the vehicle.

The other issue it has is that the condenser fan runs erratically with either just ignition on or engine running. I can hear the relay under the passenger seat clicking away merrily to its self. I suspect these faults are related.

Re: Mercedes Sprinter 2002 sprintshift 2.7 CDI

Posted by Alan Lange <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3293' width='330' height='300' border=0 style='border:none;'> on January 15, 2014, 10:47 pm, in reply to "Mercedes Sprinter 2002 sprintshift 2.7 CDI"

Hello Peter, It doesn't look good but I found this. •Fuse #7 under the steering column powers the SKREEM module and the horn. If you have a "start error" and the horn is not working check this fuse.
•Sometimes a dead or low battery will cause a "start error". If you have a low battery, disconnect the negative battery cable, charge your battery, and then reconnect and try starting again. Leave the battery disconnected for a length of time before reconnecting.
•If your van will not start and the engine cooling fan starts running as soon as you turn on the key, this usually indicated a faulty engine computer. If you try to scan the engine computer you will find it will not communicate. Replacement will be necessary.

Re: Mercedes Sprinter 2002 sprintshift 2.7 CDI

Posted by Peter Holland <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5256' width='330' height='300' border=0 style='border:none;'> on January 20, 2014, 11:40 am, in reply to "Re: Mercedes Sprinter 2002 sprintshift 2.7 CDI"
Peter Holland

I can communicate with the engine ECU using Autodiagnos but I can't with the Mercedes Star tester. If I disconnect the gearbox ECU the fan stops running. I haven't had a chance to test it any further as yet. Thanks for the tip about fuse 7, I'll check that first.

Re: Mercedes Sprinter 2002 sprintshift 2.7 CDI

Posted by Alan Lange <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3293' width='330' height='300' border=0 style='border:none;'> on January 20, 2014, 9:32 pm, in reply to "Re: Mercedes Sprinter 2002 sprintshift 2.7 CDI"
Alan Lange

It looks like this maybe a common fault although I've not come across it. Apparently you could remove the uppermost 10amp fuse under drivers seat in the vertical stack of three unmarked fuses near the relays and larger fuses rather than disconnecting the battery. Might pay to put a temporary fused switch here if it works.

Fixed #

Posted by Peter Holland on April 14, 2014, 7:45 pm, in reply to "Mercedes Sprinter 2002 sprintshift 2.7 CDI - Non start unless you disconnect battery #"
Edited by board administrator April 17, 2014, 2:54 pm

Very strange one this. It turns out to have had a history of non start problems over the last few years. Don't you just love it when you find out the whole story only after many hours of fault finding!

This problem apparently started after the battery was replaced. I eventually came to the conclusion that my Autodiagnos tester just wouldn't communicate with the gearbox ECU. There was no fault with it, just a comms issue with my diag machine.

I found the main CAN BUS connection point in main loom behind the glovebox. Out of frustration I ran in new sheilded twisted pair cable from the immobilser, instrument panel and heater control panel back to this point. I could then reliably talk to all ECUs appart from the gearbox. The only problem was that it still wouldn't start first thing in the morning. Checking cranking voltage, I discovered that the voltage would drop below 9 volts. I got rid of the cheap and chearfull battery, fitted a decent one, rechecked cranking voltage (now didn't drop below 10 volts) and then tested over a week. So far, so good! Well, I haven't heard from the customer yet!

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