DME Coding Advice

[DarrylvanNiekerk]

Hi guys

I am having persistent niggles with my car - erratic idling on start up which smooths out when it warms and a flat / dead spot just above idle where it mostly bogs down if you don't give enough fuel on pull off or do a slow moving / low rev acceleration in second gear.

I have gone through anything and everything that could physically cause the issue which leaves a potential software issue.

I believe someone has messed with the software as the 6500rpm limit has been removed and when I unplug the MAF there is no change to the idling or running of the car.

Any suggestions on who to go to - I am based in Midrand but will travel if necessary.

 

[Ahmedy]

Hi . Specs on the vehicle maybe?
Have you tried basic diagnostic tools like inpa for example.

 

[DarrylvanNiekerk]

Hi . Specs on the vehicle maybe?
Have you tried basic diagnostic tools like inpa for example.

2006 e90 320i - N46. Engine rebuild with 16000km on the engine, 190000km on the car. Awesome compression, new coils, sparks and sonically cleaned injectors - spray patterns and pulses looked great when the rail was out and injectors visible.

I haven't tried INPA as I don't have access to it, been using a generic OBDII unit.

Checked for codes, been following live data streams on injectors, O2 sensors, MAP etc. and all seems normal. Have adapted VANOS and anything I can think of. Checked for vacuum leaks, replaced oil separator, it doesn't consume oil or coolant. VANOS solenoids cleaned and tested, non return valves cleaned and tested, oil pump stripped, cleaned and inspected.

Recently did an engine flush and added Ceratec, also run fuel injection cleaner additive through the system twice 2000km apart.

 

[momo1]

have you checked fuel pump and fuel filter?

 

[DarrylvanNiekerk]

That was one of my thoughts.

As far as I am aware it is a singular unit with the filter integrated into the pump, how would I go about testing it?

 

[momo1]

maybe this can help

https://www.youtube.com/watch?v=ck4_eJoGpxQ

 

[DarrylvanNiekerk]

maybe this can help

https://www.youtube.com/watch?v=ck4_eJoGpxQ

Awesome, thank you.

 

[DarrylvanNiekerk]

A quick update.

I decided to drop the car off at a shop in Midrand so they could check AFRs and hopefully pinpoint any issues as I am just going around in circles.

The car did its usual cold start rough idle which mimics a misfire but isn't and there were no stored misfires. It did show a fault regarding air temps affecting the VANOS inlet pointing to the MAF being faulty.

They can't play further until this is resolved so I bought a new MAF from Imcomex and tomorrow they will install and test from there.

 

[DarrylvanNiekerk]

Further update.

The air temp issue has gone away but still getting problems with inlet VANOS.

Theory is that the inlet camshaft rectarings are worn allowing oil to pass through and VANOS cannot adjust adequately. Once the car warms the gap is taken up slightly and rough idle disappears but VANOS is still affected.

I'm really not looking forward to that job, the only bonus being able to swap out a noisy lifter or two.

 

[DarrylvanNiekerk]

So here is the current situation.

Car went on the dyno to check AFRs. It is a bit down on power and running a bit rich.

Technician tried to check software and see what is going on and if anything could be adjusted but could not access the DME, it literally will not let him in.

I asked if he could flash it and reinstall the latest software and he said normally he can but my DME is not letting him see or do anything, it is literally locked.

 

[Ahmedy]

There are alternatives for flash tuning. You could do it yourself but it could prove risky. I've bricked mine once before 😂.

I'm unsure what dme you're running so you could visit bimmer tuning tools as a start to find out if you're dme is tunable or not . They have a serial checker and will further provide the software to do it .

Alternatively if you'd like , I know of someone based in potchefstroom that may assist with flash tuning.

 

[DarrylvanNiekerk]

There are alternatives for flash tuning. You could do it yourself but it could prove risky. I've bricked mine once before 😂.

I'm unsure what dme you're running so you could visit bimmer tuning tools as a start to find out if you're dme is tunable or not . They have a serial checker and will further provide the software to do it .

Alternatively if you'd like , I know of someone based in potchefstroom that may assist with flash tuning.

Thank you very much, I have a bit of research and thinking to do it seems.

At least in the short term I know I'm not running lean which was my big concern.

My options appear to be limited, costly and not without risk:

1. Replace DME including locksets with second hand working unit.
2. Find someone with a clean DME that will definitely straight swap.
3. Add a piggyback unit to take over management of the engine.
4. Find someone that can guarantee they can flash the DME without bricking it and install standard / latest software.

Sucks to be me right now.

 

[Ahmedy]

Ive also come to learn that if something fails , bmw have a safe tune in the map that usually over fuels.

It is a bit of a costly affair depending on which route you choose.
A locksmith I know sorted a 320d e90 last year . Costed around 20k to replace and reprogram the dme on that vehicle. Not too certain what they did exactly that costed that much .
Flash tuning usually costs around 2-4k . Piggybacks around 4-8k.

There's still something that itches the back of my mind. If the dme was never tuned , why over fuel ?
To me that spells for an incorrect lambda sensor or another sensor elsewhere. I've learned the hard way with sensors . Strictly original bmw .

 

[DarrylvanNiekerk]

Ive also come to learn that if something fails , bmw have a safe tune in the map that usually over fuels.

It is a bit of a costly affair depending on which route you choose.
A locksmith I know sorted a 320d e90 last year . Costed around 20k to replace and reprogram the dme on that vehicle. Not too certain what they did exactly that costed that much .
Flash tuning usually costs around 2-4k . Piggybacks around 4-8k.

There's still something that itches the back of my mind. If the dme was never tuned , why over fuel ?
To me that spells for an incorrect lambda sensor or another sensor elsewhere. I've learned the hard way with sensors . Strictly original bmw .

I too have a sneaking suspicion something is off and it is in "safe mode" but cannot pinpoint the exact problem/s hence the AFR test.

I replaced one O2 sensor because it didn't look great, now when I check the fuel trims they are within spec though one bank is pulling and the other pulling, ever so slightly. I cannot find a vacuum leak that would cause this.

My issue now is that we can't do a proper deep dive because there aren't any codes being thrown and the DME has been messed with but we have no idea to what extent.

I have replaced / thoroughly tested almost every component that could cause the issue and am now sitting in the dark.

Cleaned injectors, new coils, new sparks, checked continuity and voltage on coil plugs, cleaned solenoids and non return valves, no oil leaks, used electronic cleaner on every plug and sensor - I am so confused.

 

[DarrylvanNiekerk]

So, here is where things are right now.

We narrowed the intake fault to most likely being the VANOS adjustment unit and possibly worn rectarings. I would replace the exhaust rectarings at the same time and check for worn lifters and replace.

Above will be step two as I first want to resolve the DME issue. I see a number of companies selling DME units that have been "virginised" and have the latest software which can be straight swapped. If this is indeed accurate then I will go through with my car and do the swap there - no work no pay.

Right now the hesitation and dead spot have all but disappeared so the replacement MAF is working nicely. I can understand there being a slower pickup as the engine is small with a heavy body and the fueling is a bit rich but things are a lot better already.