ASC light still comes on after DTC codes disabled, any ideas?

LVSBB6 · Oct 21, 2009, 08:43 PM

I suspect those of you running stage 2 modifications have encounted similar situations. My ASC light would come on when I do WOT pull from 2nd gear or higher gear from low rpm (ie: 2500rpm). Several reasons could cause this: additional modifications that makes more power, the change in weather temperature so the ecu is seeing more loads, or airflow/torque table not adjusted.

Using 2nd gear, doing WOT from 2K rpm and I could duplicate the issue every time.

It goes something like this: doing WOT from 2K rpm, once the revs builds towards 4K to 4.5K rpm the ASC would trigger on me, the rev just swings to redline without the car moving forward, it feels like stepping the throttle on neutral. You won't get any CEL and can reset the ASC light by re-starting the car.

I have adjusted my Airflow #1,2,3 tables to max (255) between 3500 to 4500rpm, plus I have disabled the DTC codes. So I'm not sure what is there to be done in order to get rid of the ASC light problem.

Those who have their Airflow and Torque tables tuned, would you mind posting the maps?

Thanks in advance!

UT_EvoX · Oct 21, 2009, 09:35 PM

I have all of those codes disabled, and started getting the ASC/Service Required when I tuned at sea level. Seems I was making just enough more torque down there for the torque monitor to trip out at around 4500-5000 rpm. I adjusted the torque limiter tables around that range with a bit more headroom and it helped a bunch. But, yes, from what I've seen, the ASC light still comes on when you exceed the limits, even with the codes disabled.

Keep in mind if your tables are set too high, you can get the same behavior as the actual is that much lower than the expected.

BigT · Oct 22, 2009, 04:45 AM

Try it with ASC off and see what happens. Wheel spin maybe?

UT_EvoX · Oct 22, 2009, 07:56 AM

Quote:

Originally Posted by BigT

Try it with ASC off and see what happens. Wheel spin maybe?

This has nothing to do with ASC being on or off, it's just the light pops on with the Service Required screen when you hit an airflow or torque limiter overage condition.

There is no way for the ASC/Service Required to go away without turning the key to Ignition off then back On.

LVSBB6 · Oct 22, 2009, 08:20 AM

Sounds like the problem is within the torque table, rather than the airflow table.
I am triggering the light around the same rpm range, at which throttle position did you start making the adjustment?

Quote:

Originally Posted by UT_EvoX

I have all of those codes disabled, and started getting the ASC/Service Required when I tuned at sea level. Seems I was making just enough more torque down there for the torque monitor to trip out at around 4500-5000 rpm. I adjusted the torque limiter tables around that range with a bit more headroom and it helped a bunch. But, yes, from what I've seen, the ASC light still comes on when you exceed the limits, even with the codes disabled.

Keep in mind if your tables are set too high, you can get the same behavior as the actual is that much lower than the expected.

UT_EvoX · Oct 22, 2009, 05:21 PM

Quote:

Originally Posted by LVSBB6

Sounds like the problem is within the torque table, rather than the airflow table.
I am triggering the light around the same rpm range, at which throttle position did you start making the adjustment?

IIRC I increased my tables from 40%+ TPS and above. I'm e-mailing you my current ROM right now.

LVSBB6 · Oct 22, 2009, 09:13 PM

So I tried bumping up my Torque tables (based on Cobb stage 2) in 5% increment, from 5% to 35% increase I did the 7 pulls in total, but the ASC problem still exists.

I'm pretty sure the result would be the same if I were increase the values further, makes me wonder if the problem really lies within the Torque tables...

UT_EvoX · Oct 22, 2009, 09:30 PM

Same here... unless your airflow or torque tables are tuned too high and you're tripping an under limit condition. Everything seems A-OK to me after having looked at your ROM.

I noticed no BCS cut or anything when this was happening to me. Car kept on pulling. I thought it was something legitimately wrong with the S-AWC system until I got it to go away by dropping the boost a bit.

LVSBB6 · Oct 22, 2009, 11:43 PM

I should also point out the ASC light didn't trigger when I dynoed the car, I was doing WOT pull from 2K rpm in 3rd gear just fine. I'm still running the same tuned map since then.

It is also not any issue if I was to do redline pulls from 1st gear to redline and upshifting to higher gears after. It's only happening if you say in 2nd or higher gear under WOT around 4.5K rpm.

I'm guessing the temperature drop has something to do with this, it's getting colder here in Canada so I am hitting higher loads than last season.

ScottSpeed21 · Oct 23, 2009, 07:42 PM

The ASC light has nothing to do with the engine tuning, let alone any of the Torque or Air Flow Limit tables. I had this happen when my fuel pump relay started to go bad. I would start the pull at 2000rpm and as full boost hit, there would be a hesitation and it would pop the ASC light. Since I changed the relay, the car pulls smooth and never turns off the ASC.

My guess would be any torque/load output by the engine that the ECU decides is irregular or excessive will automatically turn off the ASC and pop the service light. I have no idea if that's true, but from what others have explained from their experiences, it makes sense.

UT_EvoX · Oct 23, 2009, 08:34 PM

The same exact thing happens when you still have the codes enabled, it's just accompanied by a hard cut and check engine light/code.

Is this happening to people with higher torque outputs? If you're right, this will be happening to anybody making above that torque threshold where the S-AWC system freaks out.

gunzo · Oct 24, 2009, 12:21 AM

Quote:

Originally Posted by ScottSpeed21

The ASC light has nothing to do with the engine tuning, let alone any of the Torque or Air Flow Limit tables. I had this happen when my fuel pump relay started to go bad. I would start the pull at 2000rpm and as full boost hit, there would be a hesitation and it would pop the ASC light. Since I changed the relay, the car pulls smooth and never turns off the ASC.

My guess would be any torque/load output by the engine that the ECU decides is irregular or excessive will automatically turn off the ASC and pop the service light. I have no idea if that's true, but from what others have explained from their experiences, it makes sense.

Actually it does

The ECU controls the amount of power going to the wheels .. too much power going to the wheels will cause your ASC to come on when the limits are exceeded ..

Its a fine balance setting up the car not to trigger any CELs ..

tephra · Oct 24, 2009, 07:44 AM

Can someone explain what's occuring here, I am a little lost.

AFAIK the ASC will blink the main screen when traction is lost - it will also issue a torque reduction command to the ECU, the ECU will then basically cut the TPS to reduce power (and therefore wheel spin)

skyseer · Oct 24, 2009, 08:07 AM

Does ASC light come on on cars tuned with ecuflash and cobb ? Does tune with EcuTek solve this problem ?

UT_EvoX · Oct 24, 2009, 11:09 AM

Quote:

Originally Posted by tephra

Can someone explain what's occuring here, I am a little lost.

AFAIK the ASC will blink the main screen when traction is lost - it will also issue a torque reduction command to the ECU, the ECU will then basically cut the TPS to reduce power (and therefore wheel spin)

Correct, that is not this case.

When I was battling this, it would occur every time I dropped down to 4th at 4500-5500 rpm and nailed it. Boost would spike to 32 psi and about 310 load, and the ASC + Service Required light would come on and would not go off until I turned the ignition off. WGDC was not cut, throttle was not cut, and timing was not cut during this. No codes stored on the ECM.

Boost limit was above 310 and the threshold was set to 2000 ms, so it wasn't that. I tweaked both the airflow limit and torque limit tables as well to some success. I ended up truly fixing it by tweaking the wastegate tables quite a bit to prevent that boost spike. I did have all of the airflow and torque codes disabled, so I figured this is what happens when you trigger one of those conditions while having the codes disabled. I assumed that because when I got hard torque cuts, the same would happen but with the hard cut and the CEL + code.