Quick backstory ... bought the car, beefy motor, Procharger D1SC, SD Tuning, all the goodies, had the motor rebuilt, got it back in October and drove it for the 1,000 miles before doing the final dyno tune. During those 1,000 miles, no lights ever came on. No Service Vehicle, no Check Engine. They all came on at startup test, so everything is normal.

Fast forward to this week. I picked it up after the dyno tuning, and the Service Vehicle light is on. (Not the Check Engine) I call the tuner and he says, "Oh yeah, that's supposed to be on. It will always be on with speed density tuning since you don't have a MAF." Now I had the car running for 1,000 miles and this light was never on. Now suddenly it's on. I scanned with Torque app and OBD-II bluetooth device. No codes stored. It *could* be confusion from the dyno since rear wheels were moving and fronts were not, but in the past that's always just been an ABS INOP light that clears after 3 driving cycles. So I suspect it's something in the tune that needs to be turned off.

I don't have time to drive the car until this weekend (work work work) and it *may* clear if it's just dyno confusion. But, wondering if anyone else has run into this. If it's on due to Speed Density tuning, what does the tuner need to do to make this light not trip?

 

Take it back - if you don't have the software to disable the checkboxes., It shouldn't be on with an SD tune.

You can do a search on this forum to verify that the light can be turned off with an SD tune and/or running mafless.

Is the MAF removed or still there? Is it plugged in?

https://ls1tech.com/forums/pcm-diagn...de-normal.html

 

Fire your tuner and get a better one.
If your car has a service engine AND a CEL, then the service engine has absolutely nothing to do with the MAF. It will most likely have to do with an oil change reset or something to that effect. The MAF will throw a CEL because its an actual DTC.

 

wait, on the 4th Gen is the "Service Engine Soon" warning light simply a mileage interval for an oil change? Or is it the actual "check engine" light that comes on with a DTC? Sometimes the terms are used interchangeably, but if you've scanned for OBDII codes and there aren't any, google search "reset SES light" and see what you have to do to reset it.

 

The MAF is removed.

I have looked through and found some old threads and have copied the info. Weird thing is that it's the same guy that tuned it the first time. So you'd think he would remember how he turned it off before.

 

It does *not* have the CEL ... only the "Service Engine" light.

 

I think you can download HP tuners and read the tune - perhaps I am wrong - but you can't change the tune. Did he give you a copy of the tune so you can look at it?

It would be interesting to look at the history of the tune to see if the necessary check boxes were changed to reflect that the MAF has been removed. Hopefully your latest tune isn't a copy and paste tune. He should know better than to assume that his customers will accept whatever crap he tells them.

Do an extensive search on this forum and on others. Confirm that most searches tell you that you don't have to put tape over the light, ignore the light, or remove the light. Take this information to him and tactfully suggest that you want the light to be off even thought it's perhaps harmless to leave it on.

I don't think that the pcm in the 98-2002 pcm has the capability to remind us that our cars are due for an oil change so ignore that post.

For twenty dollars you can download this file from Maslic's site. He show in details all of the parameters that need to be disabled when switching from a MAF to an SD tune (page 226 or thereabouts). It's a cheap source of information to learn what the 'professionals' do when they supposedly tune your car instead of doing a copy and paste tune.

Or take a look at this video

Search the guide for:

Setting MAF Baseline (in SD)

https://ls1tech.com/forums/pcm-diagn...eo-guides.html

Good luck - I hope your tuner does the 'right' thing and does what is supposed to be done.
Also explain that you would like a copy of the tune the reason being you want to learn how your car's pcm works.

 

Thanks everyone.

It's back at the tuner now, think my fuel pump ate it over the weekend. So we'll address all these comments with him.