Code 29F1 DME: Fuel Pressure, Plausibility

[doublespaces]

I keep getting this code after my car has warmed up and I shut the car off to flash a map revision and this code will appear before I'm out of my neighborhood.

For some reason lately it's only been happening when I've driven for a while. My car drives fine until I shut it down and only after I try to drive again even without flashing a map it will do this.

It used to occur when I first started driving but that was on a different HPFP. I've had some battery irregularities, this is a ~90 AH AGM battery and I never see the car running at 14.x volts. I wonder if voltage has something to do with it?

 

[matreyia]

It could be lots of things, including voltage fluctuations. If you have a new HPFP then it's most likely voltage fluctuation because the pumps depend on the EKPM units for control which in turn are super sensitive to voltage variation and will affect the pumps and when the pumps are affected the ECU will note that and throw a code. So it may appear to be a bad pump when in fact it may be battery related.

Option 2 is your high and low fuel sensors need to be replaced. That will cause incorrect pressure readings which in turn cause incorrect pump flow and possibly throw a code.

Last option is your pumps are going out.

After I replaced my EKPM with the PM4 Torquebyte unit... never once got any error codes related to pumps again...ever.

 

[NoQuarter]

I think I remember from a couple years back.... When I had this with no other symptoms, I replaced the Low pressure sensor and no more problems.

 

[JimboFresh206]

Had this on a freinds 1er... Was the low pressure sensor, we did a new sensor and the revised line and it hasn't been an issue since.

Fwiw pretty sure the revised line isn't required

 

[GreyNBlueE92]

The new line has a rubber mount to limit vibrations and possibly extend sensor life

 

[doublespaces]

I think I remember from a couple years back.... When I had this with no other symptoms, I replaced the Low pressure sensor and no more problems.

Had this on a freinds 1er... Was the low pressure sensor, we did a new sensor and the revised line and it hasn't been an issue since.

When was the code being thrown do you recall the circumstances at all?

The new line has a rubber mount to limit vibrations and possibly extend sensor life

Mine has that already. It's a 10/2008 build 2009. Has 62-63k miles.

 

[Brakthru]

I keep getting this code after my car has warmed up and I shut the car off to flash a map revision and this code will appear before I'm out of my neighborhood.

For some reason lately it's only been happening when I've driven for a while. My car drives fine until I shut it down and only after I try to drive again even without flashing a map it will do this.

It used to occur when I first started driving but that was on a different HPFP. I've had some battery irregularities, this is a ~90 AH AGM battery and I never see the car running at 14.x volts. I wonder if voltage has something to do with it?
View attachment 27376

You ever figure this out? I get the same thing. I have a new Helix, hpfp, stage 2 bucketless low pressure fuel pump lpf sensor, high pressure fuel sensor. Still on original ekpm2. I have 2 maps. 1 map it doesn't happen. The other map it happens. I know I need 2 rear o2s because I keep getting a faults for o2 after cat signal.

 

[doublespaces]

You ever figure this out? I get the same thing. I have a new Helix, hpfp, stage 2 bucketless low pressure fuel pump lpf sensor, high pressure fuel sensor. Still on original ekpm2. I have 2 maps. 1 map it doesn't happen. The other map it happens. I know I need 2 rear o2s because I keep getting a faults for o2 after cat signal.

I think it's somehow tune related. What are the temps when you experience this and what are you doing?

 

[Brakthru]

I think it's somehow tune related. What are the temps when you experience this and what are you doing?

It happened in the 50s -70s degrees. I barely can get down the street before it throws ses. I'm trying the other tune now and will report back.

 

[doublespaces]

It happened in the 50s -70s degrees. I barely can get down the street before it throws ses. I'm trying the other tune now and will report back.

But once it occurs, if you restart the car it doesn't come back until the next day or something? That's what happens to me anyway.

Ask your tuner how much difference there is in the rail pressure tables.

Also, we know there is indeed some hpfp/coolant related tables. The HPFP chatter fix specifically switches your car to the non startup table.

So perhaps there is such a big jump from the warmup table to the normal operating table, the code gets thrown.

I've tried suggesting this to multiple tuners and nobody has responded about it much. I'm not convinced it's my car, I think it's at least influenced by the tune and temp related.

 

[Brakthru]

But once it occurs, if you restart the car it doesn't come back until the next day or something? That's what happens to me anyway.

Ask your tuner how much difference there is in the rail pressure tables.

Also, we know there is indeed some hpfp/coolant related tables. The HPFP chatter fix specifically switches your car to the non startup table.

So perhaps there is such a big jump from the warmup table to the normal operating table, the code gets thrown.

I've tried suggesting this to multiple tuners and nobody has responded about it much. I'm not convinced it's my car, I think it's at least influenced by the tune and temp related.

Thats good info.
Today my car has been throwing the codes each time are start and drive off. It doesn't do it on my tuners map.. it does it on the tune I'm personally building. So, im reverting back to the vcv tables I used before to see if that helps. My scalars are a little higher to get my trims in line so I'll lower them too to see if any effect. I could use the hpfp chatter fix. It usually just chatters the first minute or so after startup and sometimes at idle.

 

[doublespaces]

Thats good info.
Today my car has been throwing the codes each time are start and drive off. It doesn't do it on my tuners map.. it does it on the tune I'm personally building. So, im reverting back to the vcv tables I used before to see if that helps. My scalars are a little higher to get my trims in line so I'll lower them too to see if any effect. I could use the hpfp chatter fix. It usually just chatters the first minute or so after startup and sometimes at idle.

But the question is, after it occurs and you restart the car, does it come back while the car remains on for the second time? The SES doesn't come back on mine until the car has cooled off and I'm trying to understand why.

You probably already saw this but this is the chatter fix discussion, within the VCV tables thread:

N54 HPFP VCV Tables

Since these tables were released on VTT's website I think its safe to make it clear as day they are available for the self-tuners so now the ever lasting whine may cease and fuel shall be abundant.

bmw.spoolstreet.com

 

[Brakthru]

But the question is, after it occurs and you restart the car, does it come back while the car remains on for the second time? The SES doesn't come back on mine until the car has cooled off and I'm trying to understand why.

You probably already saw this but this is the chatter fix discussion, within the VCV tables thread:

N54 HPFP VCV Tables

Since these tables were released on VTT's website I think its safe to make it clear as day they are available for the self-tuners so now the ever lasting whine may cease and fuel shall be abundant.

bmw.spoolstreet.com

Thanks. I'll look at this discussion. I'm on the road as we speak. What I've been doing is clearing the code while I'm driving. Then, it comes right back like a min later or less. I haven't just turned the car off to see what it does. If it comes back ill try the shut off first and see.

On this tune I just revised the vcv fuel request tables to request less current, pwm and slightly less flow and it drives with no codes or ses. The problem though is I get the dip in hpfp around the 4k rpm wide open throttle. It also gives me the polygraph hpfp up and down fluctuations. That might be because I was spinning 3rd gear on a somewhat wavy road though. But it seems the lpfp goes high and low at the same time. I'm trying a map with slightly higher current now to see if it helps the dip. Not sure if I should be concerned about this polygraph hpfp.

 

[martymil]

This error mostly happens because of unstable and highly fluctuating fuel pressure swings.

Get those swings under control and I highly doubt you will see those errors again.

Next time manually log your car and look at what time the error occurred in history and look at your log and go from there.

 

[doublespaces]

This error mostly happens because of unstable and highly fluctuating fuel pressure swings.

Get those swings under control and I highly doubt you will see those errors again.

Next time manually log your car and look at what time the error occurred in history and look at your log and go from there.

Not the case for me, at least, I don't think so. Usually I'm at 1500 rpm? Imagine just leaving your driveway, car is cold.

 

[martymil]

manually start the log and see what time the error happens and see what is happening in the log at that point.

 

[doublespaces]

I've done this several times and have shown multiple tuners. I'd have to do it again likely because the code history isn't retained on the new mhd app.

 

[martymil]

there might be something wrong with your app or corrupted as my history is there and retains it on the latest rev.

 

[doublespaces]

there might be something wrong with your app or corrupted as my history is there and retains it on the latest rev.

I mean, I have the beta and none of that happened recently, aka new app therefore no history. Last time I recall was actually last year, thats how much I drive my car. My fuel setup has also changed since then, but I'm still curious about the problem. Here is an old log(on old app of course):

Hide legend Reset zoom

 

[martymil]

Did the actual error happen whilst doing this log ?