320D N47 Fuel Pre-Supply Pressure

[razirafi]

Hello to all, I am currently troubleshooting a 320D that has intermittent engine stumbling problems. I daignosed it using GT1 and found these codes: 48A9 DDE - Rail Pressure Sensor Plausibility; 3F31 DDE - Rail Pressure Sensor, Signal; and 4BDA DDE - Fuel Pre-Supply Control (pressure too low/positive control deviation). I cleared the codes and checked again. This time only the 4BDA DDE came back. I then did a diagnosis request for the 1) Pre-Supply Pressure, 2) Actual Rail Pressure, and 3) Specified Rail Pressure. What I found out was that the Actual Rail Pressure and Specified Rail Pressure were within close values of each other and also rose and fell in proportion to the engine speed. BUT, the Pre-Supply Pressure reading was way too high at about 220 Bar, fluctuating wildly, and sometimes going to zero and then back up again. According to WDS, the Pre-Supply Pressure is regulated at 4.8 to 5.0 Bar. I am suspecting that the pressure sensor is faulty but I need someone to confirm that the Pre-Supply Pressure should indeed NOT be at 220 Bar...(is it even possible for an in-tank electric fuel pump to achieve this high a pressure?) Another thing that I have noticed is that the fuel feed line with the temp/pressure sensor has a part number of 13537800666 in the BMW ETK but the actual fuel feed line in this 320D is 13537800666-04. The difference in the fuel feed line that I have is the T-fitting which is connected to the return line of the fuel injectors. I would like to check the pressure sensor out of the vehicle but I don't have the pinout (it has 4 pins) and it is not in the WDS. Can anyone share some info about this?

[razirafi]

Hello again. I would have posted this in the E90post forums but I couldn't. I got a message saying that I need to have at least three posts to be able to start a new thread so I came here. Anyway, I did further diagnosis on the problem and hooked up a mechanical pressure gauge to the fuel feed line and got a reading of about 3.8 to 4 Bar. I also scoped the in-tank fuel pump power terminals and found the voltage to be about 8.15 Volts (although in GT1, the voltage readout was about 9.1 Volts). It is highly likely that the pressure sensor is at fault (or maybe the wiring?) The DDE is seeing a very high pre-supply pressure (from the sensor) and sending this information into the fuel pump control unit (EKPS) and in turn the fuel pump control unit is setting the fuel pump to it's minimum operating state in order to bring down the pre-supply pressure to about 4.8 to 5 Bar (but the actual pressure is only 3.8 to 4 Bar). This also most likely explains the stumbling since at higher fuel demand the HPFP will experience fuel starvation. The rail pressure sensor signal plausibility error is probably a side-effect which was caused by this since it is a high pressure type and when the realtime pressure at the moment of high fuel demand became so low, it could not get a "logical" signal as it went below its bandwidth. I will try to manually map out the wiring to this sensor and do further checks.

[redlinegarage]

Hello again. I would have posted this in the E90post forums but I couldn't. I got a message saying that I need to have at least three posts to be able to start a new thread so I came here. Anyway, I did further diagnosis on the problem and hooked up a mechanical pressure gauge to the fuel feed line and got a reading of about 3.8 to 4 Bar. I also scoped the in-tank fuel pump power terminals and found the voltage to be about 8.15 Volts (although in GT1, the voltage readout was about 9.1 Volts). It is highly likely that the pressure sensor is at fault (or maybe the wiring?) The DDE is seeing a very high pre-supply pressure (from the sensor) and sending this information into the fuel pump control unit (EKPS) and in turn the fuel pump control unit is setting the fuel pump to it's minimum operating state in order to bring down the pre-supply pressure to about 4.8 to 5 Bar (but the actual pressure is only 3.8 to 4 Bar). This also most likely explains the stumbling since at higher fuel demand the HPFP will experience fuel starvation. The rail pressure sensor signal plausibility error is probably a side-effect which was caused by this since it is a high pressure type and when the realtime pressure at the moment of high fuel demand became so low, it could not get a "logical" signal as it went below its bandwidth. I will try to manually map out the wiring to this sensor and do further checks.

Sorry peeps, our first time on a forum so sorry if forum rules not followed, mate have you got any updates in regards to this issue because im having the exact same problem's as you had, also i cant seem to locate that particular sensor on my n47. The car is very temperamental because it drives good for weeks and then randomly doesn't start for days. Now the car is running and the main codes that stay permanent are 4BDA and 4BDC, also 4e1e and a few more that i will update on as soon as i get home. Im stuck with this car and its doing my head in so any clues would be wicked

[razirafi]

Sorry peeps, our first time on a forum so sorry if forum rules not followed, mate have you got any updates in regards to this issue because im having the exact same problem's as you had, also i cant seem to locate that particular sensor on my n47. The car is very temperamental because it drives good for weeks and then randomly doesn't start for days. Now the car is running and the main codes that stay permanent are 4BDA and 4BDC, also 4e1e and a few more that i will update on as soon as i get home. Im stuck with this car and its doing my head in so any clues would be wicked

hello..sorry for the late reply as I haven't been back here for the past few weeks. anyway, the sensor that I mentioned wasn't really defective as it was the GT1 diagnostics that gave that reading in Status Requests, leading me to believe that the sensor was defective. When I checked it again using ISTA/D (ISID), it gave the correct pressure reading of about 4.3 Bar. The culprit that caused this problem was the wiring to the fuel rail pressure sensor. When I wiggled the wiring at about two inches from the sensor connector, I was able to reproduce the symptoms exactly so what I did was switch the engine off and disconnected the connector and slightly crimped the terminals to give it a tighter fit. Up until now the vehicle is running OK. Before finally nailing down the problem, I also did the Test Plans for the high pressure system and the others relating to the fuel system and I got mixed results...sometimes the GT1 would indicate that the system was OK and sometimes NOT OK...It was quite bewildering until I tried wiggling the wiring close to the connectors. There is also a system description within GT1 and ISTA/D which helped a lot...if you need this info please let me know so that I can send you a copy to your email address.

[vigan]

I've a problem with the E70 X5 2007. delays in the ignition and as he works one hour and then stops will not start. diagnostic thet that has this problem 4BDA DDE presupply Fuel pressure control, can you help

[bashtanu]

Hi,
I'm having exact the same error and with GT1 it also shows 200 bars pressure. Unfortunately I do not have the ISTA/D to check with.
I've been with the car to BMW service and they told me to change the fuel filter, then to rewrite the low pressure pump software and if none of these works, then I should change the pump.
I would like to try and check also the wiring to the fuel rail pressure sensor, but I don't have any idea where to start looking. Do you have by any chance some documentation related to this, or could you be more specific on what checks should I do?
Thanks
Bogdan

[Rob1983]

Has anyone managed to get to the bottom of this? I have the same problem

[Miki46]

Did you find the problem? I have the same problem...

- - - Updated - - -


Hi,
I'm having exact the same error and with GT1 it also shows 200 bars pressure. Unfortunately I do not have the ISTA/D to check with.
I've been with the car to BMW service and they told me to change the fuel filter, then to rewrite the low pressure pump software and if none of these works, then I should change the pump.
I would like to try and check also the wiring to the fuel rail pressure sensor, but I don't have any idea where to start looking. Do you have by any chance some documentation related to this, or could you be more specific on what checks should I do?
Thanks
Bogdan

Did you find the problem? I have the same problem...

[ade1]

Hello to all, I am currently troubleshooting a 320D that has intermittent engine stumbling problems. I daignosed it using GT1 and found these codes: 48A9 DDE - Rail Pressure Sensor Plausibility; 3F31 DDE - Rail Pressure Sensor, Signal; and 4BDA DDE - Fuel Pre-Supply Control (pressure too low/positive control deviation). I cleared the codes and checked again. This time only the 4BDA DDE came back. I then did a diagnosis request for the 1) Pre-Supply Pressure, 2) Actual Rail Pressure, and 3) Specified Rail Pressure. What I found out was that the Actual Rail Pressure and Specified Rail Pressure were within close values of each other and also rose and fell in proportion to the engine speed. BUT, the Pre-Supply Pressure reading was way too high at about 220 Bar, fluctuating wildly, and sometimes going to zero and then back up again. According to WDS, the Pre-Supply Pressure is regulated at 4.8 to 5.0 Bar. I am suspecting that the pressure sensor is faulty but I need someone to confirm that the Pre-Supply Pressure should indeed NOT be at 220 Bar...(is it even possible for an in-tank electric fuel pump to achieve this high a pressure?) Another thing that I have noticed is that the fuel feed line with the temp/pressure sensor has a part number of 13537800666 (tel:13537800666) in the BMW ETK but the actual fuel feed line in this 320D is 13537800666-04 (tel:13537800666-04). The difference in the fuel feed line that I have is the T-fitting which is connected to the return line of the fuel injectors. I would like to check the pressure sensor out of the vehicle but I don't have the pinout (it has 4 pins) and it is not in the WDS. Can anyone share some info about this?
Hi mate did you manage to get to the bottom of this issue can you please get back to me many thanks ade

[MacTapatalk]

I will add to the list.

2011 X5 35D. Had the 4BDA then other codes to go in limp. Dealer replaced the filter, pump, controller before I cried uncle cost wise. Still getting 4BDA yet with the new parts. (Frustratingly useless dealer)

Cheers,

[RadYork]

I've a problem with the E70 X5 2007. delays in the ignition and as he works one hour and then stops will not start. diagnostic thet that has this problem 4BDA DDE presupply Fuel pressure control, can you help
I have same fault on my x5 E70 40D 2011 did you managed to sort it out? Thanks