Ajtedder03

Hey guys I recently purchased a 99 automatic, it came with a old hyper tech tuner for the early 2000s I plugged the tuner in and it said that a the tune from the device was already programmed so I returned the tune back to stock the cooling fans didn’t want to come on at high speeds anymore so I re-tuned the car they were working again now the old tuner says the flash memory is corrupted, contacted hyper tech they told me to buy a new unit. I then purchased the SCT X4 tuner and it keeps giving me a error code saying cannot save stock tune error code #110b8. I took car to dealership and had PCM flashed, cooling fans are only coming on at low speeds again and car feels like it has less power. SCT TUNER is still not working I pulled all the fuses they told me too I did battery reset all of that. Please help.

Chopper_Doc

From a stock LS1 Tune, cooling fans are disabled above 35mph, and if AC is on, then it's 65mph.



Not sure about your tuner though. I don't know anything about those. But the fans are really a non-issue, as this is by design. Fans aren't going to do squat except possibly slow the air down coming through the radiator above a certain speed. Apparently GM says that speed is 35. I hope that helps, at least with the fan thing.

tblu92

Ditch the hand held tuners--Especially one you bought online like E bay---There have been many stock updates on LS tuning and the older LS handhelds are just out of date
If you had the dealer re load the stock tune back in it then you should be able to write over that stock tune with HP or EFILIVE and get a real tune---

Are you getting any trouble codes ?????

Chopper_Doc

Handheld tuners imo are dangerous little pieces of outdated technology because you are making PCM changes without any data on hand. Tuners do not just change things in the tune “just cause” we feel like it, no, we use data points and make changes based on those to meet a goal.

With no mods to the engine, tuning isn’t really required, however, you can gain a “little” power from redoing a stock tune. Leaning out the Power Enrichment table to a more palatable 12.5 - 12.8 is first thing, then possibly pushing the spark up SLIGHTLY to see what happens on the dyno are a few quick ways to gain a few horsepower. Also disabling the torque management and tweaking the trans tables are other mods you can put on a stock tune to make the car more fun to drive.

Beyond that, don’t expect to gain 100 horsepower from modifying a stock tune. You have to add parts that would support that type of gain and get a “real tune” after that. A handheld is not going to cut it if you make changes to your airflow, which in reality is the only way to increase horsepower. Fuel is just a ratio to air. So more air = higher fuel requirement. It’s funny when dudes just swap injectors for no reason and then wonder why they have problems after the fact.

But I digress. I agree with the above post of buying HPT or EFI live. There is more open source support for HPT by the way, and there are even open source tuning software cracks out there. Check over on LS1 tech stickies in the PCM section for the free stuff.