scan says coolant -40, truck runs bad help

[jason86]

i took off my buddies six-gun off his 02' lb7 and loaded neens econ tune, same op system, and the truck thinks its -40 deg coolant all the time, and the scans say the same thing, it revs at startup and idles rough. of coarse it runs like crap because all the tables that follow coolant temp. i even loaded the stock tune into the truck with the banks unhooked and it still read -40 on the scan and on the guage and ran like crap. what could be the problem guys. as soon as i hook up the banks the truck runs great. i feel bad because he paid $100 for a license and i cant for the life of me get it to work. and this is not the first truck i have tuned.

[joecar]

Coolant sensor: broken wire or disconnected.

[jason86]

we changed the coolant temp sensor and that didnt change anything (waste of money). as soon as we put the banks back on with the same stock tune it reads normal on the guage and scan.

[GMPX]

I don't really know the Banks system, but does any of the wiring need to be modified for it? Sounds to me like when the Banks is back on the truck it is bridging a gap that makes the coolant temp sensor work, when it's not there you have an open circuit.

Cheers,
Ross

[jason86]

no the banks six-gun just piggy backs into the main harness connectors. no modifying any wiring.

ross im really feeling bad about this because its a good friends truck and he paid for the license and i cant put a tune in that doesnt act up. im at a loss.

wierd thing is that when i first loaded a tune the banks was still hookd up and everything worked good. i had the power tune loaded that ran good, left it in and then unplugged the banks and the truck imdeatley acted up on the first start and then ran perfect after hooking the banks back up. it makes me think it might be a pin in the harness is loose or something from hooking it up and unhooking it. any other thoughts?

does anyone have a wiring diagram for the main harness connector under the hood so that i can test the coolant sensor wire.

thank you

[joecar]

I have a look in eSI... what truck is it...?

[jason86]

its a 2002 chevy duramax lb7 motor

what is esi?

[jason86]

found it. it was a pin pushed out of the main connector

[joecar]

I am sorry I didn't find the wire diagram for you (I've been using my Mac lately, eSI only runs on Windows).

eSI is the GM service manual covering 1996-2005 on dvd ($400 from www.helminc.com (http://www.helminc.com)).

[GMPX]

Hey Joe, did you know you can only use TIS2WEB on IE? Part of the login requires a button to be clicked, in Firefox the button is not clickable. This is the ONLY reason I have IE installed on my computer, most annoying.

[joecar]

Ross,

That is very annoying...

With eSI 2005 (installed from DVD) from Firefox when you press the magnifier button the TIF viewer doesn't work, and Firefox options show that I have a TIF viewer installed (IrfanView)... most irritating.