dvdcore

Hello all,

I own an E60 BMW 535d 2006 remapped to ~350bhp and 700nm. It also has DPF filter phisically removed , and also an ECU remap to ignore the DPF.
Car runs fine, with black smoke on hard acceleration but only on the first seconds after pushing the pedal.

The problem i have is that it goes in limp mode in DS mode , BUT only after i reach ~230km/h where i think it goes to 6th gear.
Then the big turbo doesn't kick at all , until i restart the engine.

This occurs only if im am keeping the acceleration pedal to the floor in kickdown and only in DS mode.
If i go with 3/4 of the pedal in D or Manual it will still go to the top speed and no limp mode.

I mention that i changed the MAF sensor, vacuum hoses, the 2 turbo valves and temperature sensors.
Also in DS it runs fine 12-13s from 100-200km/h (60-120mph). So no pull loss in any situation.
Only in 6th gear in DS mode 220-230km/h, full kickdown triggers LIMP MODE.

Any idea why it does this?

My suspicion is somehow related to the injectors, because some times in idle the engine doesn't run so smooth, like not all 6 cylinders are working fine. If i do a quick run, then the engine runs smooth on idle.

Could one or more injectors malfunctions cause a limp mode at high speed?

JasonH

You really need to get the fault codes read. However to me that sounds exactly like the vacuum hose to the wastegate. Mine fractured so the wastegate didn't close. Limp mode was only triggered under extreme use, much as you describe. The fault that was logged was something like intake manifold overpressure (caused by the wastegate not opening). Car ran great otherwise though!

dvdcore

Thanks for the tip.
I got the errors read and checked again all the vacuum hoses. This is what the tester says:

Charge-air-pressure control of large turbocharger, control deviation: Charge-air pressure too high:

And it displays these 3 items that might cause the problem:
- Turbine control flap
- Compressor bypass plate
- Wastegate valve

The mechanic tested all the 3 above with the tester, and they all seem to be engaged by the vacuum hoses.
He also tested the boost pressure sensor.

So everything seems to be working fine mechanically speaking, but when hiting ~4200rpm in 5th or 6th gear it triggers limp mode.
I checked BMW documentation and it seems at around this revving the large turbo should be partially bypassed.
So i am guessing that the pressure sensor detects too much boost in the large turbo, despite being actually bypasseed, and the ECU thinks one of the 3 above is not working properly.

Perhaps i should try with a new ecu remap, less aggresive.

Rest of the time runs great:

stiker

If everything runs fine in D but you have the problem in DS, that would point to a software problem.

Maybe your remap does not agree with the software active when the auto box is in DS...

Mike

dvdcore

I tried several times and seems to be doing it in D and manual mode as well but at a higher speed .
In DS at ~230km/h
In Manual in 6th gear and D around 245km/h

I suspect to be the large turbo wastegate not opening enough after 4200rpm to bypass partially the air that goes in.
But if the wastegate is shut closed i don't understand why its going in limp mode only in 5th/6th gears.

For now im driving below 220 , but if i find the solution to this matter I will come back with it here.

A friend of a friend with a 335d remapped says it triggers limp modes sometimes at higher speeds as well, and the cause is the intercooler not being enough efficient for this boost and power.

IrishLad

Hi,
I have an almost identical problem and was wondernig did yuo find a solution.
Mine only started in the last few days and happens when on the motorway, luckly I have a code reader/eraser in the car so can erset the code while driving and it returns to normal.

The error is boost pressure too high, same as yourself.

Can you let me know how you got on, I have a safe remap done (extra bit of torque) and DFF etc all still fitted.

Thanks!

IrishLad

Hi,
Haven't been on here in a while, life getting in the way
The car is still going into limp mode, not sure what the map set the boot limiter to, or even what bar the pressure is set up to.
Think I can get a presssure readout of boost pressure from the Bosch KTS650, so can get an idea, bit is there anyway to see what the limiter is set to for the pressure.

Apart from this is there anything else that could cause the issue?

Thanks.

seanjordan

I was having the same issue with my vehicle going into limp mode. I tried everything and nothing was working (SW upgrades, new parts, etc.) . I took it to a Indy shop and my mechanic told me that my Trans fluid was over heating because of the thickness from driving it too hard and wasnt shifting when it was suppose to building too much pressure in the engine. I didnt believe him at first. After he change the fluid I took it for a drive a what do you know everything works as new. It even work in DS and I havent been able to use that in over 8 months. I dont know if you are getting the limp mode because of a trans fault or not but I hope this helps. I was told if you are a hard driver change your trans fluid every 30K. The transmission like to go in safe mode so it wont overheat or blow the engine.

dvdcore

Hello again,

@seanjordan I have had my torque converter changed 1 year ago and while with it, also the tranny fluid. That didn't solve any problem regarding the limp mode.

@IrishLad I have not solved the problem yet. Meanwhile i bought an OBDII scanner to connect my android phone to the car.
I took several readouts regarding the Turbo boost level.
The stock map of an E60 535d is 1.85 bar. Tuned cars usually have a max boost set to around 2.3 bars.

With the pedal to the floor, in first 3 gears the boost is max 2.0 bars, in 4th at around 200km/h goes to ~2.3 bars.
When changing to 5th gear and hitting the limp mode around 230-240km/h the boost readout is 3.6 bars!!!

The guy who tuned my ECU map, re-checked it, and says that my map limits the turbo boost to a max of 2.3 level, so it can't go to such level.
He faults a sensor for wrong boost readout level, and so the car thinks there is too much pressure and goes to limp mode. But why does it do that when going to 5th and 6th gears only?

If anyone has a suggestion to fix this, please help. Or perhaps what sensor should i try to replace.

Tiago

Did you found the answer?