[rbm]

In addition I found this.

The volumetric exhaust gas flow is greater....

Can this have something to do with the tune?

 

[rbm]

Thanks for your answers guys. Clavurion i saw that the sensor is in the DDE (

) so not easy to replace. Maybe they changed something to this values concerning the EGR to stay closed? Maybe anybody has any idea?

 

[rbm]

Dear @garrrs. No I did not. I checked it in stationary and during a running engine

 

[rbm]

Dear @rasa golf thanks! Would be nice to let me know! Than I can call the tuner.

 

[rbm]

In addition I was thinking something I don' understand:

• During exhaust gas pressure sensor test the exhaust gas pressure sensor before diesel particular filter gives normal values (see screenshot with green bars)
• During a cold engine the exhaust counter pressure test gives negative values. In ISTA is than mentioned that if values below 0 are reported you should renew the exhaust gas pressure sensor

I don't get the discrepancy between these two. Can the sensor still be faulty if it gives normal values in the exhaust gas pressure sensor test? Hopefully I make my question clear

 

[rbm]

@teejaybee ok. Do you know what the tuner has done wrong?

 

[rbm]

Dear @teejaybee. I was thinking the same. Although I tested this somehow. What I did was during the exhaust gas pressure test see what happens when I manually opened the EGR valve. The values which I then read are lower not higher. But the errors concerns a minimum differential pressure undershot. So this doesn't make any sense because the difference would than be even lower

I don't get a CEL. I called the tuner. They have seen this kind of errors on VW diesels but not with BMW. The engine runs perfect and the EGR is still regenerating without any problems. What I could do is a couple of thinks now.

• I can ask them to rewrite the original MAP
• Activate the EGR again
• Leave the settings and ask them to delete the error codes in the MAP

For now I think I will keep an eye on it too see whether it gives any problems. If it doesn't I prefer leaving the EGR closed and only open during regens. Maybe than just ask them to remove the codes.

 

[rbm]

@Clavurion Will this give a problem with the DPF even when regens are successfully? ISTA is not mentioning any consequences on regen of the DPF when I look in the errors. I just don't no exactly what's best to do for now

 

[rbm]

Thanks for the answers

@Clavurion. Tonight I was thinking the fault concerning the difference between the exhaust gas pressure before diesel particulate filter and the ambient pressure is greater than a limit value is measured after run off with the engine off. So indeed static as you mentioned. See below. But how can this static value be changed with a tune? Just thinking? maybe just replace the sensor for the sake of it to be sure.

ISTA: "The fault is detected when the difference between the exhaust gas pressure before diesel particulate filter and the ambient pressure is greater than a limit value. Limit value: 60 mbar. When the engine is stopped, monitoring takes place for a certain test period during after-run of the control unit and when a waiting period has elapsed. Waiting period: between 4.7 s and 6.7 s (version-dependent)."

@rasa golf. Thanks! Was your car giving the same errors in ISTA? Just curious. The tuner had too much fuel top end?

 

[rbm]

Will ask the tuner to reflash the original file and see what happens. Keep you guys up to date.

 

[rbm]

Have you managed to see the 60+ mbar difference in the sensors yourself?
It's measured for 2 seconds, 5-7 seconds after engine off.

Have tried to measure it my self with putting the engine off and look at the figures but didn't see any 60+ mbar. Do you have any experience garrrs with this error?

 

[rbm]

I guess it's this sensor:

 

[rbm]

Haven't had it on mine. Have you asked the tuner to put it back to stock?

No I will. It's fairly a long drive. The strange thing is it happened after a couple of hundred kilometers. Not directly. No the error comes quite fast I think.