Hello team!

I have a dilemma that the dealer can’t seem to figure out. My car goes on limp mode and won’t build boost past 8-9 psi. I keep getting codes 0236 and 2227. I have taken it to the dealer 3 times and the damn codes never come up again. Sam has it tuned and I run a e30 tune all the time. I thought that was the problem so I changed it to the regular 93 tune. It kept coming up so I changed it back to stock and the problem persisted. I heard someone mention the battery being low here at the forum so I checked it (1yr old btw) and it was about 25% charged. I charged it for 24 hours and the problem seemed to be clear! So I got a new battery and the problem is back like before. The car runs amazing on e30 when it’s working fine. 10.3@135 1/4 mile and 6.4-6.5 60-130mph. Any help, tip, advise or suggestion would be massively appreciated.

 

Check the connections to the boost sensor on the Y pipe. Clean it out with some 91% isopropyl alcohol and a tooth brush, connector and the sensor. Also might be good to pull the sensor off and clean it with some MAF cleaner.
If that doesn't work, maybe buy a new boost sensor.

 

Awesome, thanks for the advice! I’ll try that out as soon as I get home!

 

According to The Book if P2227 is stored without P0069 (Intake Manifold Pressure Sensor) then the DME is faulty.

P0236 is Boost pressure sensor implausible, with faulty sender, loose/corroded connectors/wires as possible causes.

Quite possible that The Book has P0069 mixed up with P0236.

But, yeah, checking / cleaning boost sender terminals is a good start.

 

Worf, can you please share some more details on "The Book"? Is this a service/repair manual? Thanks in advance.

 

Excerpt from workshop manual posted, not by me, to teh interwebs a while ago entitled: 991 Fault Codes.PDF

 

did you fix this?

 

Yeah, seems to be working fine now. They cleaned the throttle body and the MAP sensors connections. That seemed to do the trick

 

Thank you for your reply. I’ve been getting the same problem as you described. I’ve changed the top map sensor and it was working fine for a few months but I’m getting the same issue. I heard there’s another sensor but I don’t know where. I will try taking the bumper off and do as you described.

 

Last year I “solved” a knock sensor code on CarChick’s 991S by cleaning the motor oil out of the multi-pin DME connector.

No. I’m not kidding. Yes, I’m sure.

Head tech at my Dealer told me they have seen DME’s, literally, filled with oil.

Any leak on these engine in the vicinity of the engine harness (any harness really) that gets into the harness covering will wick its way throughout the harness.

I blame modern weather pack style connectors where only the conductor is crimped rather than ‘old school’ where conductor has a crimp and insulation has a crimp.

Anyway…

We are all going to become intimately familiar with how to clean electrical connectors.

​​​​​​…. since these “modern” connectors have traded oxidation failure modes for fluid failure modes.

 

Other sensor is on the passenger side intake manifold.