I need some answers. Right now at the top of my revs I hit over 18psi and throw my DSC light on.
1. Why is this happening?
2. How do I make this not happen?
3. I like the boost I am making, just I like my traction control to be on.
It mostly happens at the top of third, or thetop of fourth.

 

Do you have a code scanner? If this is what I think it is your exceeding the design parameter of your MAP sensor triggiering the lights. (I assume after a few restarts the code clears) LEt me see if I can find the link

 

https://www.northamericanmotoring.co...ad.php?t=59142
And correction from last most , manifold pressure sensor not MAP sensor, sorry its been a long night. You pretty much are just giving it more air than the ECU knows what to do with, not indicated in this link but I thought I read somewhere that MTH or another tunning software could be adjusted so you'd keep your DSC.

 

Manifold Pressure is MAP..your boost is spiking to 18 psi it sounds.. would be normal for a turbo car or a twincharge, but then if you were the way i would fix it is get an external wastegate and port the dump. Don't ask how i know.. my roommate is one crazy mate

 

It sounds like you're getting wheel slippage when you're hitting 18psi. DSC doesn't even look at map values, so boost pressure wouldn't have a direct effect on the DSC. DSC looks at throttle position, wheel speed sensor values, steering angle sensor values, and yaw rate.

So all in all it sounds to me the DSC light is blinking when you hit 18psi and not staying on like it's a DSC fault. In which case you need stickier tires
If it DOES stay on like it has a DSC fault, I have no idea what it is

 

i've heard that too high a reading on the MAP on a stock ECU can throw a DSC light on certain cars.

 

Is that so? That's something I wouldn't expect at all. I'll need to find out more info on that

 

I have the same problem. My DSC light will come on, and if I really overboost the SES light will come on. P0108 see it every day! I'm sure that the twin charge guys have something to over-ride this sensor! -- Johan

 

Can anyone explain this to me? I have never heard of DSC light coming in w/ overboost. And i can't think of why it would either...very interesting

 

One of the great things about living in the UK is I can get 98 octang and I hit 20 pounds of boost quit frequently but the DSC light coming...........never. Not sure what even the connection is.

 

are you hitting the rev limiter? if so...umm you need to shift BEFORE that happens

other than that...well that's just wierd...I never used my DSC so...it's on AUTO OFF! LOL

 

Yeah just recently I took my car out on the track and topped it out (135 in 5th, 138 in 6th) but after I was done my DSC was off. I was wondering what this was and I guess it's overboost (I have 19%er)...

Tuls, I thought you were gonna say something along the lines of 18psi? I'm boosting 28psi lolol

 

yeah...but that would be off topic...LOL

 

SO the consenus is shift sooner and you get to keep DSC?

 

oops, yeah i edited my post

 

in my car when the dsc light comes on that just means its working (when it comes on for a short period of time or flashes) is it just staying on when you hit that psi? like its turning off?

 

so ya, i guess i'll just shift earlier? I am not hitting rev limiter, im shifting just before it. But how do the twincharge guys get around this?

I know how the DSC light works in normal conditions. Like mine flashes thru first and part of second, and in third if its wet out. But this is not normal DSC operation, this is during speeds well over what I would be spinning tires in and it STAYS ON

The 19% guys know what I'm talking about, I have only gotten P0108 once (at least I think thats what it prolly was).

 

Are you able to turn the DSC light off when it stays on? Or do you have to shut off the car to reset it?

Also I think the P0108 code is caused by boost briefly hitting past 36psi, making the DME think there's a short in the map sensor. Perhaps it's hitting 36psi because the bypass valve isn't responding fast enough when throttle plate closes.

Oh and I say 36psi because 36psi is the max pressure the MAP sensor can detect (just the one in the intake manifold).

 

The MCS's T-MAP is a 2.5 bar sensor, which means it should have linear output to about 22PSIg. 18PSIg shouldn't be triggering any sort of errors. I've pulled dyno runs with my 19% pulley and my boost gauge say 19.5PSIg at redline [whether that's accurate or not is another story] and no SES/DSC light. Also, Maximusmini's twincharged setup at 22PSIg threw no T-MAP related codes. Sooo, what's causing the P0108? Bad Sensor?

 

hmm...then maybe it wasnt that code...
and no i can't just flip the switch to turn off the DSC light, I have to turn the car off and back on.

 

Barnabas: 36psi - meaning absolute pressure, not gauge pressure. A 2.5 bar sensor equals 36.75PSIa. Take that and subtract 14.7PSIa [which is typical barometric pressure] equals 22.05PSIg [g for gauge, a for absolute]

 

Are you able to extract any code due to the DSC light? That'd make life alot easier when trying to figure out why it's throwing the light. I'll look into the DSC issue tomorrow..very puzzling

 

msfit, search around, I've read other posts of this happening. Check with mth, I think they are able to programme new parameters.

Barnabas, the map at 36psi is absolute pressure, so about 20 psi could be a problem, although I've heard that 18psi is when people start seeing the dsc light.

 

MISFIT-Have you tried Andys VGS mod? If this is the cause the VGS will force the BPV to close quicker and acctually forces it closed, I did this to get a little quicker throttle response cost about $3 and satisfied my but dyno.

 

first thing I do in my twincharge set-up is turn off the DSC and make sure my passenger is hooked in the harness properly. Simply Turn it off. Most likely the solution will be solved. Also, if possible get ahold of a scan tool and see what comes up.