Two Codes, Poor Boost.

[Tommeh]

Okay I just updated my JB4 to latest Rev. 6/4 and did some pulls.

The car has had some issues with boost for awhile now and this isn't my first time trying to figure it out. Car is modded and I cant even pull stock boost without getting a engine permanence reduced message. About a month ago I brought it to Cobb and had a smoke test done to check for boost leaks they said there is none.

Today after I updated the JB4 I wanted to test the Shift light function and did some pulls. First pull was good no errors no problems. Got to 4th at 120 pulling hard with no codes.


Second pull got to like 2nd at 4.5ish RPMs and got a "Engine performance reduced" Or something like that. The message pops on the Nav screen and shows a picture of a engine in orange.

I checked the codes on the JB4 and it gave me two as followed:

30FF Boost Under Target -- Possible Boost Leak.
2C78 Lambda probe behind catalytic converter 2, signal

I'm assuming the first code is my target is mid teens and I cant ever get above 6-11 even though the car has more than enough mods to go beyond that.

Code two has something to do with o2 sensor would this effect anything?

Any ideas why my boost output is low, and getting a performance reduced issue?

[Kamal]

boost leak? Check your intake tract piping...

your other code sounds like an O2 sensor gone bad... have you put in downpipes recently?

[turtleking]

my thing is similar with a JB3... i've been told it's the hose clamp on the BMS DCI, the vaccuum hose near there... either way, it keeps happening and it seems like the techs don't really figure it out but just tighten everything all around.

one thing is i get the cut power but the 30ff doesn't show up anymore.. not sure what the deal is with that.

[Lambobimmer]

I think that your o2 code is 2C7B

I had this fault code recently as well but I don't think that my problem was the same as yours.

[Tommeh]

Yeah idk what it is. Im dropping it off a local bmw certified shot to get lt looked at. I also had three codes for torque injectors or something T_T

[BahamaBart]

I recently upgraded to a JB4 and the car was running great. I ran map 1 and ran map 5 (auto tune).

I got a deal on downpipes and had them installed and everything went funky. I threw two codes 2c7f and 2c6a - these are associated to the rear lambda senors on the cat. The details on one references "trimm" and the other "muddled".

I then got the 30ff code along with the eng. pic half in orange on the dash. It implies a boost leak. Bear in mind that I've been boosting to 13.2 lbs with no issue. I do admit that with the DP install, I got on the car real quick (not fully warmed up).

When running cat-less you should get these code 29F5 and 29F4. I got these codes ONCE and continue to get 2c7f and 2c6a. Could they have gotten reversed? perhaps but it doesn't look so. could they have gotten damaged? perhaps but they were unplugged and left dangling. I pulled the JB4 off and will send it to Terry to test. By the way Terry has been great, trying to help me figure out whats going on.

The shop that did the dps had a bmw friend look at the car. I have no clue what he did but now I have these two codes 0083 or 1015. The service light soon was on and my BT scan tool would not clear them out. I left the car with them and plan on meeting with this bmw friend to understand what he did. After he touched the car I test drove it - first run 5 lbs boost, second 6lbs and third 7lbs - perhaps this was do to heat soak for its over 90 in Miami.

does anyone know what fault code 1015 is ?

[Mike@N54Tuning.com]

Originally Posted by BahamaBart

I recently upgraded to a JB4 and the car was running great. I ran map 1 and ran map 5 (auto tune).

I got a deal on downpipes and had them installed and everything went funky. I threw two codes 2c7f and 2c6a - these are associated to the rear lambda senors on the cat. The details on one references "trimm" and the other "muddled".

I then got the 30ff code along with the eng. pic half in orange on the dash. It implies a boost leak. Bear in mind that I've been boosting to 13.2 lbs with no issue. I do admit that with the DP install, I got on the car real quick (not fully warmed up).

When running cat-less you should get these code 29F5 and 29F4. I got these codes ONCE and continue to get 2c7f and 2c6a. Could they have gotten reversed? perhaps but it doesn't look so. could they have gotten damaged? perhaps but they were unplugged and left dangling. I pulled the JB4 off and will send it to Terry to test. By the way Terry has been great, trying to help me figure out whats going on.

The shop that did the dps had a bmw friend look at the car. I have no clue what he did but now I have these two codes 0083 or 1015. The service light soon was on and my BT scan tool would not clear them out. I left the car with them and plan on meeting with this bmw friend to understand what he did. After he touched the car I test drove it - first run 5 lbs boost, second 6lbs and third 7lbs - perhaps this was do to heat soak for its over 90 in Miami.

does anyone know what fault code 1015 is ?

Any time a code comes up you use the code to troubleshoot. 30FF = boost leak, o2 codes = o2 sensor problems, etc. If the o2 sensors are damaged the JB4 will normally detect that and failsafe itself to stock boost levels so you don't damage the motor until you resolve it. Damaging o2 sensors is common when installing downpipes if the shop is not experienced and doesn't take their time with them.

Mike

[BahamaBart]

Picked up the car yesterday - catless dps = on, JB4 = off. Car is back to its oldself BUT my check eng. soon light is on and the codes are 1015 and 0083. I ran the check all modules and it all came up GREEN however when I checked under the engine for fault codes 1015 and 0083 appeared. 0083 does not trigger the light but 1015 does.

I may wait until the weekend but I will reinstall the JB4 and give it another go. Its been a really strange trip and I dragged Terry through every step. He was limited in his ability to help but I must say how great it was to have someone there at all times.

I am still in the quest to find out what the 1015 code represents.

[BahamaBart]

while she feels good - all the fault codes re-appeared. 30ff and a couple of car codes.
The only good news is that the BT cleared out all the codes including the 1015 and 0083.

So where am I? In no mans land - so I don't see much choice but to take the DPs off - see if that eliminates some of the codes. And then take it in to find the boost leak (even though its boosting solid 8s. I would never had thought that such a simple mod would cause so many problems. Oh, well - part of modding.