jack 7220

I am having a problem with the car computer. When I changed to 3.42 gear in my 2003 automatic I keep getting the code 1870.

A guy used a H.P. programer to change the computer. It seems to work for about 75/100 miles then the code comes back.

I do have the LS1 program but have not used it yet, because I don't know how.

Can anyone help or tell me what to do ?

jack 7220

thank you jack

10-42 Cop

I'm about to do the same Mod.....I would be interested to know the reason also.....Before I do it.....Thanks

TLKSCHP

Do you have Ls1 edit or Hp tuners? It's not the end just a minor set-up change. I didn't get the code because I went to a vacuum controled shift but still had to adjust for shifting.

Mike Mercury

the H.P. is supposed to handle gear scaling. Now... that doesn't mean the device operator did all the things necessary.

P1870 means that the TCC slip error tables were not changed during the reprog and the PCM thinks there is a malfunction (excessive slippage) in the tranny or TC - when there really isn't any problem with the tranny/TC.

Before you double check the programming - are you certain the TC is locking - and actually not slipping excessively ?

gojo

Your PCM is expecting the trans revs versus the rear end pulses to be what was programmed before. When the trans revs exceed the expected for a certain period of time it's interpreted as slippage, sets the code and goes into protection mode(hard shifts). The tuning programs have a speedometer section and in that section there is "Gear Scaling". It may not have been done right or not saved right before programming. In Edit and HPT the changes have to be saved before the entire file is saved.

jack 7220

I have the LS-1 Edit, I have not used it. The guy I went to had the H-P and had used it before so he used that one. He has moved out of town. How can I use the LS to make the right adjustments ?

gojo

You will need to download the program using Edit. You should do that anyway since he is gone. Now that you have the program in Edit's format, go to the Speedometer section and select Gear. Input the tire and gear info. Make sure to "Apply". Then save the program and use it to program your PCM. Become familiar with the procedure for using Edit, before you program.

TLKSCHP

gojo

Have you tried reprogramming, yet?

Mitch C

TLKSCHP

I just got your e-mail dated 2/10, man thats slower than the postal service. If you still need help I sent you my phone number and I will pm it to you incase that takes 4 days also.

gojo

Jack,
After you reprogram you can upload your PCM to HPT and check the file to see if it's taking.