Advice needed pls - worth fixing? Error code: “2AAF”

IZ · 03-07-2023, 04:54 PM

Hi all,

Recently we purchased a BMW 1 series, 2010, E87 116i N43 Sports Hatch.
- 110K miles
- Timing chain kit done
- 1 year warranty

In the first week of owning the car it had a hard time turning over and wouldn’t start (it was cranking). We took this to a mechanic and they did a diagnostic which came back with the Error code: “2AAF” - Fuel Pump, plausibility.

They changed the low pressure fuel pump (pressure was low at 3 bar and is now back up to 5.5 bar). This solved the car not starting (turning over at all) but it still cranks for a while especially after longer commutes (takes 8+ cranks which is pretty nerve racking).

Replacing the pump has not removed the error code “2AAF” and the next step is to replace the Fuel Pressure Sensor.

Other issues:
There are also slight dips in power when we drive the car, not massive but enough to notice (also we think there is a bit more exhaust smoke than normal, but we’re not sure as this is our first BMW).

The annoying thing is that the warranty company is only going to pay for the next bit of work if it fixes the issue with the car, otherwise they won't.

The Garage has said it might be this (the Fuel Pressure Sensor being replaced), but it also might be the fuel injectors - they’re unsure and they need to follow the process to find the issue.

Do you think replacing the Fuel Pressure Sensor will solve the issue? This is the first BMW we have bought and the car is still under warranty, we are trying to work out if this is likely to only get worse or go down a very costly rabbit hole of repairs. Because we might decide to return the car since it’s been less than 30 days since we bought it.

Any advice would be really helpful and appreciated.
Thanks!

PRTSB1M · 03-08-2023, 12:07 AM

N43 is not a common platform on this forum, but it seems the 2AAF code does point to fuel pressure issues. What color is the smoke coming from the exhaust? If it's black, then you're getting excess fuel into the combustion chamber. Do you know if your mechanic reset adaptations after replacing the low-pressure pump? The car may have learned to run on the failing pump and now that it is back to full pressure, it is overcompensating (unless you reset adaptations).

03-07-2023, 04:54 PM	#1
IZ Registered 1 Rep 1 Posts Drives: BMW 1 series, 2010, E87 116i N Join Date: Mar 2023 Location: UK iTrader: (0)	Advice needed pls - worth fixing? Error code: “2AAF” - Fuel Pump, plausibility. Hi all, Recently we purchased a BMW 1 series, 2010, E87 116i N43 Sports Hatch. - 110K miles - Timing chain kit done - 1 year warranty In the first week of owning the car it had a hard time turning over and wouldn’t start (it was cranking). We took this to a mechanic and they did a diagnostic which came back with the Error code: “2AAF” - Fuel Pump, plausibility. They changed the low pressure fuel pump (pressure was low at 3 bar and is now back up to 5.5 bar). This solved the car not starting (turning over at all) but it still cranks for a while especially after longer commutes (takes 8+ cranks which is pretty nerve racking). Replacing the pump has not removed the error code “2AAF” and the next step is to replace the Fuel Pressure Sensor. Other issues: There are also slight dips in power when we drive the car, not massive but enough to notice (also we think there is a bit more exhaust smoke than normal, but we’re not sure as this is our first BMW). The annoying thing is that the warranty company is only going to pay for the next bit of work if it fixes the issue with the car, otherwise they won't. The Garage has said it might be this (the Fuel Pressure Sensor being replaced), but it also might be the fuel injectors - they’re unsure and they need to follow the process to find the issue. Do you think replacing the Fuel Pressure Sensor will solve the issue? This is the first BMW we have bought and the car is still under warranty, we are trying to work out if this is likely to only get worse or go down a very costly rabbit hole of repairs. Because we might decide to return the car since it’s been less than 30 days since we bought it. Any advice would be really helpful and appreciated. Thanks!
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03-08-2023, 12:07 AM	#2
PRTSB1M Lieutenant 297 Rep 429 Posts Drives: AW3 1M Join Date: Feb 2015 Location: Thunderdome iTrader: (0)	N43 is not a common platform on this forum, but it seems the 2AAF code does point to fuel pressure issues. What color is the smoke coming from the exhaust? If it's black, then you're getting excess fuel into the combustion chamber. Do you know if your mechanic reset adaptations after replacing the low-pressure pump? The car may have learned to run on the failing pump and now that it is back to full pressure, it is overcompensating (unless you reset adaptations).
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