98 Trans Am Tuner and Fan issue

**MR.Dick** · 06-08-2008, 06:57 AM

Posted in general help an no answers...ill try my luck here im new.

Diablo Sport and Superchips only make a tuner for 99 LS1 and forward. Does anyone make a tuner for 98. I read the computer is not compatible...Can i just change the computer for one from 99-02? or is it more complicated than that?

My check engine light is on saying either fan 1, wiring or its relay is damaged. Does anyone know when these fans should turn on? 1 then2 or both at the same time?

**purplebat66** · 06-08-2008, 11:57 AM

your first fan goes on at 210 the other fan goes on when the ac is turned on it maintains the car below 210

**MR.Dick** · 06-08-2008, 12:15 PM

Thanks you seem to know what ur talking about...Which is the first fan? Im guessing the one on the left when looking at it from the front of the car...?

**purplebat66** · 06-08-2008, 12:18 PM

the one on the drivers side is the primary fan

**96Firebirdformula** · 06-08-2008, 12:48 PM

Hypertech makes programmer for 1998.

And if car gets TOO HOT it will kick on high fan.

**MR.Dick** · 06-12-2008, 08:49 AM

Checked all fuses and relay and they are fine. Removed fan assembly and tested fan with direct current and it turned on. Has anyone experienced a similar problem i doubt i have a cut cable. The second fan turns on at 235 on the dot..checked with scan tool. my car is not overheating thanks to the second fan but i want to get this fixed please help...

**2001NBMZ28** · 06-12-2008, 10:35 AM

Post the code it's throwing. They should both be coming on at the same time, either low or high speed.

**2001NBMZ28** · 06-12-2008, 10:41 AM

Just guessing it's P0480, but the link explains the fan operation:

www.gearchatter.com/viewtopic8697.php

**MR.Dick** · 06-12-2008, 11:35 AM

Yes code is p0480. I actually found a link with all the information on the post you just gave me earlier but The scan tool that i used (autozone's) does not give me an option to turn on the fans or maybe i just could not find it. The brand was Actron. That is step 1 so im kind of stuck there...it talks about the schematics but there is no link anyone know where i can get that?

**MR.Dick** · 06-12-2008, 11:37 AM

where are those circuits they talk about located and ground wires...all i can find is the plug from the motors that head towards the fuse box then migrates with tons of other cables.

**2001NBMZ28** · 06-12-2008, 11:54 AM

Maybe this will help, there's a schematic you can enlarge: www.gearchatter.com/viewtopic8648.php

BTW must be the stock fan settings in the PCM according to the temps in the link and when your high speed kicked on. Low speed should've come on at 226.

**0rion** · 06-13-2008, 12:09 AM

fan 1 on 226 off 219.......fan 2 on 234 off 227

Have you tested those relays? Try swapping that #1 relay out with another relay such as the air relay and see what happens.

**MR.Dick** · 06-13-2008, 05:11 AM

Yeah i swapped the relays and nothing but i spoke to another member here who had similar issues he recommended that swithc fan motors and see if it still does not work. He said his fan use to spin but not fast enough and when he replaced it problem solved. Im going to switch and go from there.

**MR.Dick** · 06-13-2008, 11:19 AM

I swapped fans and nothing changed. So that for sure disqualifies the fan motor as the issue. I checked my not blown fuses with a tester and they are working properly. Fan 1 does not even turn on with the AC. Any other ideas am i missing something could the comp not be sending the signal to turn on? Does the temp sensor command the fans on or is it the computer? According to the scan tool i hooked up the comp knows the temp. I just dont want to take to an electrical "specialist" without doing all i could...

**0rion** · 06-13-2008, 11:26 AM

read that 3rd paragraph in the link 2001nbmz28 posted. It explains how the pcm grounds that circuit to get fan 1 on. High speed uses all 3 relays but you say that on high speed your number 1 fan still isn't working? If that's the case I would definitely start looking at the relay 1 circuit for your solution. Make sure the pcm is grounding that circuit then start chasing wires.