X5 E53 D Intermittent Starting Failure

[MickyW51]

Good morning, as I am new to this club will apologise in advance if this is not in the correct place or by descriptions are inadequate.

This is a desperate call for help. I have owned this X5 for the last six years. It has only 220K and been a perfect vehicle. But!!!!

About five weeks ago it developed a starting problem. The motor would turn over, but it failed to start immediately and would take 2-3 before it would start.

It would show the "Fuel Inject System" error on the dash until it started.

When it started it would run perfectly. Smooth, full power.

Took it to my BMW garage and they said the scan showed it needed new Glow plugs. These were replaced.

It started normally for the next week, but the starting problem continued. Sometime taking hours and many attempts before it started.

Took the car back to the garage, this time they said it was the low pressure fuel pump failure and needed replacing. Also done.

Problem continued. Advised it was the fuel pump control relay that was the real problem. Also replaced. $ now starting to add up considerably.

The problem continues. it starts and runs perfectly for a day or two then wont start.

From my own testing, I found the low pressure fuel pump was not functioning when it would not start. I checked the pump control relay and found that it was not operating either.

I would always get the "Fuel Inject System" when I turned the key, even without having the engine turn over. By continually turning the key and not engaging the starter, after 5-500 attempts, the fuel pump would start and the "Fuel Inject System" message would not show.

As there is no error codes showing, my BMW experts have simply given up. Auto electricians wont touch it, and some other experts have suggested it could be any of the control modules, but have no idea which one. 

Can anyone please give me some idea as to how I can get this problem diagnosed and hopefully fixed.

Cheers.

Mike W

[Greydog]

Morning Mike

Welcome to the Forum

I am not a diesel driver/owner but both sons our daughter and other family members are, and "dads" garage is free and has a beer fridge 🤣

From memory (better check what I say as I get older) the X5 has a (a) Tank pump this should move fuel either side of the saddle tank so it can be picked up below a 1/3 of a tank, (b) Inline fuel pump just ahead of the fuel filter this pushes fuel to the fuel rail through the high pressure pump. As the car runs well once started the high pressure pump seems ok. So I would be checking the low pressure side first.

Logic tell me that the DDE sends a signal to the Fuel Pump Relay which in turn activates the pumps (tank and inline) So I would check the connections at the DDE unplug and use electrical contact cleaner (not WD40) on all pins and the plug, test for continuity between the pin in the DDE and the relay. Same with the relay to fuel pump check continuity (also check earth continuity) BMW use common earth points (comb type) I had weird random faults that traced to a common earth point in the spare wheel well.

If all checks out OK then it is a sensor check, fuel pressure sensors and fuel pressure at the fuel rail ignition on engine off. If everything is checking OK I have read (some time ago) that there is a pressure relief valve on the high pressure pump if it sticks the pump will have trouble building pressure.

I use BMW 1.4.0 for 90% of all diagnostic on the beemers owned by family and friends plus I have INPA/ISTA for newer models. My old laptop has programs for Volvo, Mercedes, VW/Audi and an old Foxwell  for general stuff (my wife thinks it is better I smell of beer and oil the beer and perfume 🤣) What are you using to read codes and live data as it will need a BMW specific reader to get the right information

Just the ramblings of an old bloke but I hope it helps

Dave

 

 

[MickyW51]

Thanks Dave,

I greatly appreciate the informaton.

Unfortunately I have already checked all the DDE and earth connections and they are all fine. As are the sensors.

What is so confusing is that it starts and runs perfectly for some time ( all yesterday) but then fails to start. 

After starting this morning, I stopped the motor and then tried to start it again. Without turning the motor over, I got the "fuel inject system" error showing.

This continued for another 18 times when I turned the engine on but did not turn it over. Then the warning disappeared , the fuel pump started and so did the motor.

It started again every time I tried for the rest of the day.

I can't wait for tomorrow.

Any other ideas would be greatly appreciated.

Regards.

Mike

[Greydog]

Hi Mike

There was a post some time ago on one of the US sites that random non starting issues were being suffered by a 4.4 petrol owner turned out to be a faulty ignition switch. Worth checking ?

You say sensors checked did you include the Crank sensor ? 

Dave

[MickyW51]

Thanks again Dave.

I found this information form a British Co that seems to describe exactly my problem. 

I will replace the DDE and see if it works.

For your informaton try this link

https://www.ecutesting.com/common-faults/bmw/bmw-x5-e53-30-ecu-fault/

Regards 

Mike

[Greydog]

Morning Mike 

Used ECU Testing many times with the Volvo's ABS issues were common 2 850R 3 V70T5 1 V70R  Dealer always said the same "never seen this before" "we will have to order a complete ABS unit from Sweden" Found BBA Reman and ECU Testing, both could fix the issue but ECU were allays faster turnaround.

Lets hope it is a good fix

Dave

[MickyW51]

Hi Dave,

Thanks for your help.

Eventually found the problem after spending a fortune.

It was the DDE power relay having a high resistance contact.

$60 fixed it.

Before it was replaced, I simply removed the relay cap and separated the contactor arm from the body.

Cleaned both surfaces and all works perfectly

As the relay was not making a good electrical contact, it was only providing an intermitant  low voltage supply to most of the engine control systems.

You can measure the voltage between any of the three 20A fuses (located next to the DDE) and ground.

I hop this will help others in the future.

Regards 

Mike W

[Greydog]

Morning Mike

Great information 

Glad its fixed enjoy your beemer now

Dave

[jimbobs310783]

On 6/9/2021 at 12:39 AM, MickyW51 said:

Hi Dave,

Thanks for your help.

Eventually found the problem after spending a fortune.

It was the DDE power relay having a high resistance contact.

$60 fixed it.

Before it was replaced, I simply removed the relay cap and separated the contactor arm from the body.

Cleaned both surfaces and all works perfectly

As the relay was not making a good electrical contact, it was only providing an intermitant  low voltage supply to most of the engine control systems.

You can measure the voltage between any of the three 20A fuses (located next to the DDE) and ground.

I hop this will help others in the future.

Regards 

Mike W

Where Is this DDE relay located please 

 

[Greydog]

Main fuse relay box under the bonnet