Tuning question

B2usmc · July 18, 2022

Truck is a 99 Sierra, has 01 Silverado ECU. I have a built 5.3, 228r cam, 4l80, headers, tsp valvetrain...truck runs good. It was tuned prior to me owning it (I assume since it runs perfectly). There are a few things I need to change (airbag light after Escalade cluster swap and stupid battery warning). Do I need a tuner like HP tuners or is there a way to avoid spending that money? I also don't want to get HP tuners and lose the tune that is on it because it runs well and I'm not situated to both buy a tuner and have a custom tune built at the moment.

shakenfake · July 18, 2022

Airbag light is soldering in a transistor and a couple of resistors onto the circuit board to get it to go away.

I do not know what battery light you speak of. When I did my Denali cluster swap I only had the airbag light.

https://www.sc1.me/99Guages/Airbag.htm

Here is how to fix the airbag light.

Edited July 18, 2022 by shakenfake

B2usmc · July 18, 2022

Good write up, it's unlikely I'll do that, I'm not confident enough soldering to mess with the circuit board. The battery light is flashing on 10 seconds off 5 continually. Simply put it isn't a 3 wire alternator and the computer is looking for the f terminal that doesn't exist... research says this can be turned of in a tune or I can add a wire (some have success, others don't) to the pcm. Obviously I would rather just uncheck the ses box in the tune... pretty sure I can do the same with the airbag in the tune. I'm happy to buy the hp tuner, but don't want to lose my current tune (not sure how it was tuned before I bought it)

CamGTP · July 19, 2022

HP Tuners can't do anything airbag related.

It can change the systems options for the alternator but I've never tried it myself to see if that does truly turn that light off.

HP Tuners will also not erase the current file on the truck, it can only read what is there and then change it from that point. So long as the previous tuner didn't lock the computer, you will be able to change things on it.

shakenfake · July 19, 2022

13 hours ago, B2usmc said:

Good write up, it's unlikely I'll do that, I'm not confident enough soldering to mess with the circuit board. The battery light is flashing on 10 seconds off 5 continually. Simply put it isn't a 3 wire alternator and the computer is looking for the f terminal that doesn't exist... research says this can be turned of in a tune or I can add a wire (some have success, others don't) to the pcm. Obviously I would rather just uncheck the ses box in the tune... pretty sure I can do the same with the airbag in the tune. I'm happy to buy the hp tuner, but don't want to lose my current tune (not sure how it was tuned before I bought it)

If you'd be comfortable sending it to me I'd be willing to do it for you.

I'm confused on why you are running a different alternator then. Why not just switch to a stock one?

B2usmc · July 19, 2022

I assume the stock harness wasn't swapped when the computer was? The harness has a 1 wire plug, I think the computer wants to see the f terminal. Good to hear about the tune...I'll probably but the HP tuner. Can I just pull the bulb.for the airbag light...it seems completely unnecessary to me.

shakenfake · July 20, 2022

That should not be an issue. The harnesses between 99-02 are all the same.

Hell I put an 04 alternator in my 99 and had no issues.

I cannot remember if that bulb is soldered in or not. Part of me says yes but the other 1/4 says no. BUT the overall answer is no if you want to pass inspection. That light needs to come on, whether it goes off or not does not matter but they need to see the light.