Common 98 Issue? P0103 and Blowing Engine Control Fuse
08-31-2004, 08:48 PM
#1
Common 98 Issue? P0103 and Blowing Engine Control Fuse Ok..well to make a long story short my 98 is having pretty big problems here lately.
Bottom line is mister Horist and I are messing with the car tonite and have found that my car is throwing the P0103 code as soon as I got WOT. This is tossing the car into speed density and thus low octane tables and the car is only seeing 15 degrees of timing at WOT, making it a turd. The car is also seeing 3-4 degrees of KR when tossed into speed density. This is also causing major **** when I try to start the car cold in open loop and drive it with this code running. It'll have no throttle response and seem like its running on 4 cylinders at part throttle between 2-3K rpm..gas mileage has been dogshit.
The other problem is pretty strange,too. I noticed about a month ago when doing a random fuse check that I had blown the 15 amp blue one called "engine control". We checked it tonite and it was blown again. replaced it and went out and beat on the car and it did not blow again, just the MAF issue..also threw a TPS code but we understand that p103 can set that one off, and it only did that once.
Basically I'm looking to see if anyone can shed some light on this in any way. We did a search and saw a good bit of mention that this is a common 98 problem of sorts...any solid truth to this?
The fuse is pretty strange..does anyone A--Know what this fuse controls/is tied into and B--had this problem,too?
I currently have 3 maf sensors in the garage, two stock ones and 1 SLP 85mm..the problem has persisted over the last couple weeks with both stock ones..have not played with the SLP one. I checked for vacuum leaks as well..based on flammable brake cleaner testing and looking at my Ltrims after logging its pretty obvious there is no vacuum leak.
Thoughts/suggestions...shoot me whatever ya got..thanks in advance
Bottom line is mister Horist and I are messing with the car tonite and have found that my car is throwing the P0103 code as soon as I got WOT. This is tossing the car into speed density and thus low octane tables and the car is only seeing 15 degrees of timing at WOT, making it a turd. The car is also seeing 3-4 degrees of KR when tossed into speed density. This is also causing major **** when I try to start the car cold in open loop and drive it with this code running. It'll have no throttle response and seem like its running on 4 cylinders at part throttle between 2-3K rpm..gas mileage has been dogshit.
The other problem is pretty strange,too. I noticed about a month ago when doing a random fuse check that I had blown the 15 amp blue one called "engine control". We checked it tonite and it was blown again. replaced it and went out and beat on the car and it did not blow again, just the MAF issue..also threw a TPS code but we understand that p103 can set that one off, and it only did that once.
Basically I'm looking to see if anyone can shed some light on this in any way. We did a search and saw a good bit of mention that this is a common 98 problem of sorts...any solid truth to this?
The fuse is pretty strange..does anyone A--Know what this fuse controls/is tied into and B--had this problem,too?
I currently have 3 maf sensors in the garage, two stock ones and 1 SLP 85mm..the problem has persisted over the last couple weeks with both stock ones..have not played with the SLP one. I checked for vacuum leaks as well..based on flammable brake cleaner testing and looking at my Ltrims after logging its pretty obvious there is no vacuum leak.
Thoughts/suggestions...shoot me whatever ya got..thanks in advance
08-31-2004, 10:38 PM
#2
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Basically I'm looking to see if anyone can shed some light on this in any way. We did a search and saw a good bit of mention that this is a common 98 problem of sorts...any solid truth to this?
Here is a copy of the GM TSB: http://web.archive.org/web/200111080...06-04-007.html
08-31-2004, 11:01 PM
#3
FormerVendor
If you have some spare o2 sensors, try swapping out the fronts, and check the 02 wiring as it goes past the header.
The o2 heaters are on the same circuit as the MAF sensor, and I have seen them (or their wiring) as the cause of blown fuses in the past.
The o2 heaters are on the same circuit as the MAF sensor, and I have seen them (or their wiring) as the cause of blown fuses in the past.
08-31-2004, 11:52 PM
#4
Jim, can you do anything for me on this software issue if I bring the car by?
I was told you could with ls1edit...I will call you at the shop tomorrow morning.
Will do on checking that wiring. The 02's are new..put them in right before you tuned the car for me, but I will check that wiring.
I was told you could with ls1edit...I will call you at the shop tomorrow morning.
Will do on checking that wiring. The 02's are new..put them in right before you tuned the car for me, but I will check that wiring.
09-01-2004, 12:02 AM
#5
TECH Senior Member
Plus the fuse that's blowing is the engine control fuse... the engine sensor fuse is what blows when the o2s, o2 heaters, or MAF have a problem ... at least on my car that's what happen...
Sean's car's setting the P0103 right when we go WOT it seemed... so timing sux and we're in speed density ... but it wasn't blowing the fuse when setting the code (so i think that's a seperate issue?)
Sean's car's setting the P0103 right when we go WOT it seemed... so timing sux and we're in speed density ... but it wasn't blowing the fuse when setting the code (so i think that's a seperate issue?)
09-01-2004, 09:15 AM
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Originally Posted by horist
Plus the fuse that's blowing is the engine control fuse... the engine sensor fuse is what blows when the o2s, o2 heaters, or MAF have a problem ... at least on my car that's what happen...
Sean's car's setting the P0103 right when we go WOT it seemed... so timing sux and we're in speed density ... but it wasn't blowing the fuse when setting the code (so i think that's a seperate issue?)
Sean's car's setting the P0103 right when we go WOT it seemed... so timing sux and we're in speed density ... but it wasn't blowing the fuse when setting the code (so i think that's a seperate issue?)
Yeah, my car use to do the same thing on WOT 1-2 shifts. It would immediatly pull the P0103 code. Check to see if there is a PCM software update. If he is still on the first revision of the 98's, GM did release a fix.
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09-01-2004, 10:13 AM
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The first PCM software did the trick, now I see they offer one for my car about inproper AC cycling during WOT. Not sure what that one is about....... Imagine years later GM is still putting out fixes for the 98's......
09-01-2004, 12:07 PM
#9
What I'm wondering is how do you get this taken care of? You have to go to a dealer or what? I talked with speed and Jim is not sure what to do on it/where to look in edit, etc.
Is this something I can download and bring to him and he can take care of it for me?
Is this something I can download and bring to him and he can take care of it for me?
09-01-2004, 01:08 PM
#11
If you know anybody at a GM dealership they can reflash it for free with a Tech II. Just be sure to save your bin file. As you'll be pulling out of the dealership with a stock tune. However with ls1 edit, wouldn't the GM software be overritten when flashing the pcm with your tune again?
09-01-2004, 01:22 PM
#13
TECH Senior Member
aight... checked my HP Tuners help file
MAF Sensor Fail Frequency: This is the frequency threshold at which the VCM will set the High MAF Frequency DTC (P0103)
so that's the one we're curious in... not sure what stock values are for 98s... but Edit is showing 14336 in my 2000 binary
MAF Sensor Fail Frequency: This is the frequency threshold at which the VCM will set the High MAF Frequency DTC (P0103)
so that's the one we're curious in... not sure what stock values are for 98s... but Edit is showing 14336 in my 2000 binary
09-01-2004, 09:36 PM
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I don't know all the specifics involved...but is it possible that you are actually maxing out the stock MAF and throwing it over frequency? You do have a LOT of mods, with the old style MAF that doesn't have quite the range of the stocker.
09-01-2004, 10:21 PM
#18
TECH Senior Member
i think this is 2 seperate issues... I just checked my helms manual.. I couldn't find the engine control fuse, but looking at the schematics for the MAF, the only fuse it hits is the Engine Sensor fuse (which is fine) plus it's setting this code , but is not blowing the fuse whenever it sets the code (we replaced the fuse, reset the PCM, went WOT, code came back but fuse was fine)
The behavior is because the 103 code is being set... so it's tossing him to speed density and dropping to low octane timing tables... but the 103 code isn't arising due to the fuse blowing ... searching this site shows alot of 98s have this same problem...
we'll see...
The behavior is because the 103 code is being set... so it's tossing him to speed density and dropping to low octane timing tables... but the 103 code isn't arising due to the fuse blowing ... searching this site shows alot of 98s have this same problem...
we'll see...
09-01-2004, 11:10 PM
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Originally Posted by felton316
Here is a copy of the GM TSB: http://web.archive.org/web/200111080...06-04-007.html
Have you tried to see what software calibration the PCM is running? If it has one of the earlier 98 PCM's, he will have the P0103 problem just like me and all the other listed in the TSB.
09-02-2004, 12:59 AM
#20
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Originally Posted by felton316
Yeah, there is solid truth to this. http://calid.gm.com/vci/VINEntryPre.do and type in your VIN#, it will show you how many software revisions there have been for your PCM. I know there where 3 different versions out for my 98. The first update was for the P0103 code problem.
Here is a copy of the GM TSB: http://web.archive.org/web/200111080...06-04-007.html
Here is a copy of the GM TSB: http://web.archive.org/web/200111080...06-04-007.html
Do you just go to the dealership and tell them you want the newest calibration for my car? I found three problems with mine through that website and i'd like to get that fixed. Does it cost anything?