p12A9 Fault Code (Boost Pressure too High)

s3ri3s1 · 07-08-2019, 07:42 AM

2015 328i

I got this code recently, so I thought my boost pressure sensor was bad. I replaced it but the code didn't go away. Even after resetting and driving for a few hundred miles. I do have the Dinan Sport Tuner and Dinan intercooler on it, but I can't seem to think of what else could be wrong.

Anyone else have this issue?

RMachuca3d · 07-08-2019, 01:31 PM

Stock intake?

Its happened to a few people using the dinantronics sport tuner + cai intake.

s3ri3s1 · 07-08-2019, 05:01 PM

Quote:

Originally Posted by RMachuca3d

Stock intake?

Its happened to a few people using the dinantronics sport tuner + cai intake.

Yup stock intake. Car runs/pulls just fine

qdogg · 07-25-2019, 04:29 PM

Same happens to me occasionally. Dinantronics Sport. Everything else stock.
Take Dinan out and code clears by itself after a day or so.

s3ri3s1 · 09-11-2019, 06:28 AM

Ya I replaced it with a bm3 tune and all is well! It is weird that it didnt throw a code for months but then just started one day.

DLag30 · 10-06-2019, 10:05 PM

I just ran into the same problem. No fault codes for months running Dinan sport, then one day I get the fault code when pulling into the highway..

Gen13 F36 · 10-07-2019, 07:15 PM

No pun intended....

Boost to high... so how much HP you getting😅

Z K · 10-08-2019, 11:24 AM

I've had the same issue on my car. I had it for 3-4 months with no problem then I started getting P12a9 with my Dinan Sport. The code doesn't come up while driving, it comes up for me on start up. I can clear it but it will appear again at next start up.

I contacted Dinan and they asked me to put the unit into bypass mode. I still pop the code in bypass mode. Removing the unit clears the codes and I never get P12A9 without Dinan Sport.

I sent it back to Dinan and they sent me a new unit under warranty. No problems so far.

s3ri3s1 · 10-10-2019, 05:00 PM

Quote:

Originally Posted by Z K

I've had the same issue on my car. I had it for 3-4 months with no problem then I started getting P12a9 with my Dinan Sport. The code doesn't come up while driving, it comes up for me on start up. I can clear it but it will appear again at next start up.

I contacted Dinan and they asked me to put the unit into bypass mode. I still pop the code in bypass mode. Removing the unit clears the codes and I never get P12A9 without Dinan Sport.

I sent it back to Dinan and they sent me a new unit under warranty. No problems so far.

I wonder if it will come back even with the new unit :/

I will admit that since I went with bm3, the car seems to idle a lot more smooth than the Dinan Sport. I do miss the ability to switch to Valet mode. That is a great feature.

Z K · 10-22-2019, 12:56 PM

Quote:

Originally Posted by s3ri3s1

I wonder if it will come back even with the new unit :/

I will admit that since I went with bm3, the car seems to idle a lot more smooth than the Dinan Sport. I do miss the ability to switch to Valet mode. That is a great feature.

BM3 sounds good but I have 2 years worth of BMW warranty left on my car so I don't want to lose that.

07-08-2019, 07:42 AM	#1
s3ri3s1 Second Lieutenant 188 Rep 253 Posts Drives: alpine white 328 Join Date: Jul 2018 Location: Nashville iTrader: (1)	p12A9 Fault Code (Boost Pressure too High) 2015 328i I got this code recently, so I thought my boost pressure sensor was bad. I replaced it but the code didn't go away. Even after resetting and driving for a few hundred miles. I do have the Dinan Sport Tuner and Dinan intercooler on it, but I can't seem to think of what else could be wrong. Anyone else have this issue?
	Appreciate 0 Tweet Quote

07-08-2019, 01:31 PM	#2
RMachuca3d Captain 724 Rep 943 Posts Drives: F30 328i Msport Join Date: Aug 2018 Location: WA iTrader: (2) Garage List 2015 BMW 328i Mspor ... [0.00]	Stock intake? Its happened to a few people using the dinantronics sport tuner + cai intake.
	Appreciate 0 Quote

07-25-2019, 04:29 PM	#4
qdogg New Member 5 Rep 12 Posts Drives: 2014 428xi M Sport Estoril Blu Join Date: Apr 2017 Location: Mount Airy, MD iTrader: (0)	Same happens to me occasionally. Dinantronics Sport. Everything else stock. Take Dinan out and code clears by itself after a day or so. __________________ -2014 428xi M-Sport Estoril Blue w/ Black Dakota Leather, Premium/Technology/Cold Weather, M pedals, M rear diffuser, 435 dual exhaust, debadged, 20% 3m tint, carbon fiber wrapped interior trim, KUDA phone mount
	Appreciate 1 s3ri3s1187.50 Quote

09-11-2019, 06:28 AM	#5
s3ri3s1 Second Lieutenant 188 Rep 253 Posts Drives: alpine white 328 Join Date: Jul 2018 Location: Nashville iTrader: (1)	Ya I replaced it with a bm3 tune and all is well! It is weird that it didnt throw a code for months but then just started one day.
	Appreciate 1 DLag30103.50 Quote

10-06-2019, 10:05 PM	#6
DLag30 Second Lieutenant 104 Rep 246 Posts Drives: F80M3 & F36 Join Date: Aug 2013 Location: 94080 iTrader: (2)	I just ran into the same problem. No fault codes for months running Dinan sport, then one day I get the fault code when pulling into the highway..
	Appreciate 1 s3ri3s1187.50 Quote

10-07-2019, 07:15 PM	#7
Gen13 F36 Brigadier General 1599 Rep 3,752 Posts Drives: 428i Gran Coupe Join Date: Nov 2017 Location: Los Angeles, CA iTrader: (1)	No pun intended.... Boost to high... so how much HP you getting😅
	Appreciate 0 Quote

10-08-2019, 11:24 AM	#8
Z K Major General 1889 Rep 5,506 Posts Drives: E90 M3, G20 M340i Join Date: Jul 2011 Location: San Francisco iTrader: (3)	I've had the same issue on my car. I had it for 3-4 months with no problem then I started getting P12a9 with my Dinan Sport. The code doesn't come up while driving, it comes up for me on start up. I can clear it but it will appear again at next start up. I contacted Dinan and they asked me to put the unit into bypass mode. I still pop the code in bypass mode. Removing the unit clears the codes and I never get P12A9 without Dinan Sport. I sent it back to Dinan and they sent me a new unit under warranty. No problems so far. __________________ Auto Detailing Enthusiast!
	Appreciate 1 s3ri3s1187.50 Quote