ZWingerRyRy

iTrader: (5)

I pulled this code last night. After installing a drop in filter. I go driving to try it out pick up my friends and all, accelerating to see how it works and it was flawless til...I get to a highway cruising in 5th most of the way then i take a exit and midly accelerating off the exit in 3rd gear, car did a power loss for a second then accelerates(not the fuel cut feeling almost like a clutch slipp but rpms didnt jump, by the time i say wtf was that, i does it again cept total power loss, gas pedal was rendered useless and wouldnt give any power. Gauge cluster started beeping at me. I managed to roll my car over to the side of the highway and instantly when i park and put it in neutral the car does the limp mode(rpms jump up then jump down and so on) never had it happen i freaked out and shut my car off. Pull out my AP and found the code p1238 it gave no info though. So i cleared the code, reset the ecu, flashed back to stock map. Start it up idles normal and sounds fine. I start driving and notice my boost wouldnt go above 0 on the gauge, the car had NO POWER. No matter how much i pushed the gas, it was locked at a limit. I let it sit for about 2 hrs, try to start it again. Im still locked and no boost builds over 0.

I was using Perrin Stage 3 w/ turboback, fmic. Perrin said a drop in from them would be ok with the map, so bought it installed it then this problem happens after install. Just doesnt make sense since it worked completly fine hours before this happen with it on. Then just partial throttle off the exit and this happens and im locked in it. Its been 8 hrs now (overnight) havent started it yet. But will check it out soon. Ive seen many threads about this but most ppl get it with mbc and such. Mines all Ecu boost control.

ZWingerRyRy

iTrader: (5)

What i found, any ideas on how to fix it?

DTC P1238: Mass Airflow Sensor Plausibility (Torque Monitor)
TECHNICAL DESCRIPTION
Compare the actual measurement of volumetric effi-
ciency by a mass airflow sensor signal with volumet-
ric efficiency estimated from a throttle position
sensor (main or sub) signal.

Check Conditions
• The difference between the actual volumetric effi-
ciency and the volumetric efficiency estimated by
the throttle position sensor (main) is 0 percent or
more.
• Engine speed is 750 r/min or higher.

Judgment Criterion
• For 0.9 second, the difference between the actual
volumetric efficiency and the volumetric efficiency
estimated by the throttle position sensor (main) is
45 percent or more.

FAIL-SAFE AND BACKUP FUNCTION
• Throttle opening degree position is in default
position.

Since the fail safe is a locked throttle body, you would be limited to speed.

murlo26

iTrader: (9)

Well this sucks, hopefully you get this figured out. Did you try calling Ron?

ZWingerRyRy

iTrader: (5)

No i sent him a msg last night though. I looked it up all over google people said theres two different limp modes. Soft and Hard. Soft you just turn your car off and back on and its gone. Hard stays in the ecu til fixed, but someone on a forum disconnected the battery for awhile and it got rid of the Hard Limp Mode. Hopefully it was just a flinch from cold weather(13 degrees)and nothing serious. New Air filter prob pushes alot more air through and maf freaked out, but for a drop in it seems kinda weird to hit Limp Mode. I have it sitting with disconnected batt right now. Ill reconnect in a bit and let it idle for awhile. Maybe it needed a full ecu reset i notice the AP resets the ecu, but its not like the battery disconnect reset.

murlo26

iTrader: (9)

Hopefully that fixes it, I did read as well the battery disconnect should reset the limp mode. So far I haven't had any cold weather problems since my tune, all is going great, haven't gotten any codes yet, not even the 1235 I was expecting, or hoping not to get. I have an AMS intake too, so I would think I would get a problem before you but who knows. You might want to talk to perrin again about it.

Good luck though.

ZWingerRyRy

iTrader: (5)

Yeah i just hope i didnt kill a Maf sensor already.

ZWingerRyRy

iTrader: (5)

Yeah i should prob look into getting a tune in MN. A shelf map from Oregon(Perrin) doesnt look like it compensates very well for our MN weather .

awddyno

iTrader: (15)

Just unplug the ecu and plug it back in. I had this happen on my initial tune with the mbc and that was the fastest way I can reset the Ecu. I can see the better flowing filter doing this on part throttle. After I got my car tuned. I installed the HKS drop in filter and it leaned out my AFR about .5 from 11 flat to 11.5. I installed the stock one back in since I didn't see any gains in power at all. I didn't wanna change my tune for a part that didn't help the power.
I was getting the part throttle limp mode 1235 even with the stock boost controller but I got it figured out.

murlo26

iTrader: (9)

I dont think intakes after tuning are really going to help the X until the turbo gets upgraded. Then the intakes should help out a bit. I am running mine for sound and looks mostly now seeing as how I am pretty convinced its not adding power. But in that department I love it.

You try starting the car again yet Zwinger?

ZWingerRyRy

iTrader: (5)

No sry i took so long forgot this thread. My wg arm came off no clue how and i dont wanna find out how. Lost the pin also. So took a paper clip bent it in a better holding design and stuck it in there. That **** isnt going to pop off again.

evox350ztt

Sorry to sound like a nob... what is a WG Arm? Do you have picture? I have the same problem right now.

ZWingerRyRy

iTrader: (5)

Wastegate arm, um no picture at the moment. If its a Evo X its very easy to get to. Just pull off the heat shield on the manifold and its right there there.

STi2EvoX

Well first off, you said that you were using a perrin stage 3 map, but your sig says ecuflash. As far as I know, perrin only uses the AP and Ecutek, so I'm confused as to what's on your car. Either way, the problem that you are having is the tune, whatever software you are using. The reason that you went into limp mode is because your "airflow check" and "airflow against torque" tables (also called torque limiter tables) are not correctly set.

The description that you pulled with the code reader is pretty spot on in it's description, but basically these tables reference rpm vs throttle position, with values that are load based. If the car hits a load cell value that is higher than what the stock programming of these reference tables thinks is normal at a given throttle position/rpm, it causes a number of issues.

After a tune, these tables need to be adjusted to allow for the increased airflow at various throttle/rpm points, which means that your tune is not done correctly. My recommendation: stay away from mail in flashes. There is no substitute for a custom tune, and when you get it custom tuned, get it done by someone who understands the X's ecu and how to properly adjust these reference tables.

murlo26

iTrader: (9)

Sti2evox,

He just switched to a custom Ecuflash tune. He previously had the stg3 with AP. So that's why you are seeing that in his sig now.

Good choice on the switch btw ZWingerRyRy i bet it feels good now.

scottatyamaha

iTrader: (21)

I just got the this code also (P1238) while trying to accelerate too hard from low rpms in 5th gear. Car went into limp mode and I had to coast to the side of the road. I understand your description of what the car thinks is happening and goes into limp, but what would the main cause be......overboost or the paramiters set in the ECU? I have a AP with Perrin stage 1 and works drop in. Just want to make sure I am not overboosting.