In the UTEC manual, it says:

Today, when I dropped to 3rd gear and went WOT starting at about 4000 rpm, the CEL light flickered on twice in rapid succession and I immediately lifted. All of my fuel and timing is ECU right now and OLF is off (i.e., I'm running my base Dynoflash tune for the moment). I was only running about 19.5 psi and my AFRs were in the mid to low 10s.

My first thought was knock, but according to the manual the CEL won't indicate knock with the UTEC set up this way. I'm not sure what else it could be. Could the ECU have been thinking of setting a trouble code? Is the manual wrong and that actually was a flicker of knock? I didn't have my laptop so I wasn't logging.

Thanks for any ideas.

i would like to know also. mine does it too, even with the car running very rich. I heard if your car is tuned with the utec and the settings are not smooth/fluid the cel would flash. justin

I heard from the dealership one time that if the CEL is on constantly that it is an emissions related problem.....if it is flickering something is severely wrong...or about to..massive knocking on something....i forget

In passthrough mode (Map0) I am fairly certain that the knock light will still flash (CEL light) if it sees knock within the threshold.. HOWEVER it will do nothing to correct it.

If the light is flashing its definitely the knock sensor an the UTEC seeing enough noise to flash the light.. If its truely knock or not, well, even if the car is very rich, under a boost spike, and too much timing, you can still get knock. If it flashes randomly for no apparent reason, then there could be another problem.

But a majority of the time, its detecting what it thinks is knock. What most dont understand is that you can still get knock even with rich AFR's..

Also check the tightness of your oil pressure sensor wire. I had mine come loose once and it was causing the CEL to flash when it was moving around loosing signal.

bryan

Thats a good point.. but he probably would have seen that before he installed his UTEC if that was the case..

It was actually in Map 5, but with OLF off, zeroed fuel and ECU timing, isn't that the same as Map0?

I can believe that you can get knock with a rich mixture. I guess I'm just surprised since I was using the benign Dynoflash mail-in timing and relatively low boost.

AFAIK, no. With OLF on, Turbo-XS has like a base map loaded into maps 1 and on.
I might be wrong but from what I remember it's not the same.

Right, except I had OLF turned off.

Just make sure the input signal and output signal are close or the same.. (MAF and MOD MAF) since you may be noticing the affect of the UTEC affecting the signal (and delaying it a few milliseconds) Since its already tuned, it may be responding to the frequencies differently..

Do a data log, then use either data log lab, or microsoft EXCEL to plot the data for the MAF and MOD MAF (and the knock and RPM if you want to see exactly what your doing) If the curves are significantly different, that might be why, the knock count could also be a result of the transition from closed loop to open loop (in the stock ECU) where the UTEC takes over.. I've seen knock happen when it switches over at part throttle driving.

Setting everything to ECU is basically what MAP0 would be.. I'm not sure about how scaling would affect those settings without OLF enabled though, but you might want to check the injector scaling settings and set them default (550) if necessary.

My mistake, I must be blind. In that case it should be same as running in pass-through mode.

The CEL will flash if it is a Catalyst damaging emission failure.....like too much unburned fuel going through it. You might not have a CAT though

bump

Why the bump? In any event I was the one that started this thread. I'm pretty sure now after a lot more datalogging and tuning that I was seeing real knock and that was the reason for the light. In order to alleviate knock in the mid-range under all conditions, I've had to go more conservative on timing than the Dynoflash mail-in numbers I started with.

I've found that the timing numbers that you can have close to peak torque for a WOT run beginning at 2000-3000 rpm are much higher than what you can have if you want to be able to go WOT starting in the 4000 rpm range and not get some knock from the boost spike.