98 Suburban K2500 problems

[buddy]

I dont turn the truck off to connect or disconnect, but I disconnect the scanner from the PCM electronically. Since you have to initiate a connection to the PCM by sending it a command I dont see that there is a need to have the truck off.

The paperclip method is a little different than the way a scanner initiates communication, youre not shorting anything out with the scanner.

 

[nobby]

I always key off first.

In my years of experience with electronics etc I have found it better to be safe then sorry no matter what the theory of hot disconnectable/swappable etc. Usually it is simple extra step or two and hence in reality a no brainer. To many times with equipment I have heard the phrase 'well it should not of done that.'

Cheers
Nobby

 

[buddy]

Heck, I switch PCM chip memory with the truck running. Switching my programs on the fly from memory bank to another memory bank doesnt even cause it to hiccup. I run with the laptop connected a lot, plugging it in and unplugging, I do it all the time, more than most would on a truck, and no issues thus far.

I do disconnect from the PCM electronically, before electrical disconnection, but Im pretty sure Ive even had the USB cable pull out while monitoring while driving and it didnt do anything.

 

[Woody35]

your supposed to have the key off when you hook up the scan tool then discoonect the scan tool through the scan tool menu before you turn the power off in the truck but i sometimes dont do this if im hurrying because class is ending and all the times ive done it nothing bad has happned

 

[jrsavoie]

New PMD, resistor and KOKO. I have SES light. The local said the code was for boost sensor. Changed the boost sensor, cleared and after about 50 miles the SES came back on.

Cleared codes, unhooked the grounds and after 50 miles the SES is back on again.

Can I check for codes or something with the paperclip trick? What is the paperclip trick?

Any guesses?

It is running much better since the new PMD and KOKO

 

[ak diesel driver]

paper clip only works on obd1. have you checked vac pump and hoses? the actuato on the turbo should be really hard to move at idle.

 

[buddy]

Did the code come when you ran the KOKO, or while driving? Did you get the code number? I would never trust what someone reads off a screen necessarily, always get the code number. Do you have a boost gauge, or some reason to believe the boost sensor was bad? If it was the boost code, it can be caused by over or under boosting from what the PCM wants, like if its running the vacuum system and lost vacuum, or a Turbomaster and too much boost.

 

[jrsavoie]

It ran for about 50 miles after KOKO.

It was just what he read off the screen.

No gauges.