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P1500 & P1105: How do you fix them?

7228 Views 8 Replies 2 Participants Last post by  emitsu97
Hi guys,

I've done the searches and read the posts but was wondering if there was a definitive solution to the problem. It seems that alternator and battery changes are where the problem begins. I had my alternator and battery changed at a Pep Boys and that's when the problem started. Now, on occasion, my battery/brake/A/T lights on the dash glow dim and that's when I know it's coming. If I check the logger when those lights show dim I usually get P1500 even though there's no CEL. When the CEL finally shows it's normally a P1500 & a P1105. Then the rough warm starts begin (P1105) but what's worse is the car will start to "spaz" at will. Speedo bounces, EGT goes nuts, radio buzzes or shuts on and off with the turn signal when it's activated, door locks open and close. I've actually revved through it a couple times and all was well again. But I'd like to solve this for good.

I went to Pep Boys and they said it wasn't a problem they were responsible for, sounded like a short. I went to the local dealer and they said the same thing about it being a short but put focus on my "Aftermarket gauges" and said it would cost $79.95/hr for a tech to diagnose the problem and it would be an undetermined amount of time. I'm not willing to spend $400+, what the dealership was hinting at, to fix this. I'd rather put the money toward tools so I can get to know my car a bit better and fix this myself. Any help would be greatly appreciated.

I've had a Haynes manual for a while, been reading up on the alternator section. I've read through the post which explains the behavior of "Terminal G". I check and cleaned the connections which, from what I researched, are the problem spot of P1105.

I have basic mods. Thermal Catback, K&N, all hard ic pipes and intake pipe, MBC, Boost/EGT/AF gauges, and a Pocketlogger. All on a 97 A/T GSX.

All info and positive comments welcome. TIA.
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P1105 O2 Sensor Circuit Heating Circuit (B1-S2) -Short to B+ A
P1500 Fuel Pump Relay Circuit - Electrical Malfunction A

1105 is for your post cayt O2 sensor. 1500 is obviously for your FP relay. With 1105 normally an o2 sensor code means the sensor is bad but let the car run (idleing) and move all the wiring for that sensor around and have someone else watch your o2 readings for that sensor to see if they fluctuate (all the way high or low)
Same deal on your 1500 code. Check your connections at the relay and the wiring, use a voltmeter (test light might work if you don't have a voltmeter) and see if you loose power or ground while your moving the wiring around and smack the relay a couple of times too.

If you don't want to do all of that then you could do what real mechanics do and just replace the o2 sensor and the relay and see if it fixes your problem. :D
emitsu97 said:
Speedo bounces, EGT goes nuts, radio buzzes or shuts on and off with the turn signal when it's activated, door locks open and close.
Because of that, I'd use that manual you have and find all of the power and ground splices and connectors you can and check them. Probably focus on the ones in or around the dash.
Great, thanks for the quick reply. I'll go pick up a voltmeter (I'm oblivious to cost) and hopefully poke around before the weather gets more wintery.

Just so I'm clear, the logger description I had for 1105 was "FP selenoid malfunction" and 1500 was <No Description>. Are they different cause I'm a 2g or are they universal codes?

Thanks Big Red, you've helped me take my first steps toward becoming a Raving Lunatic, I mean, DIY DSM mechanic.
Also, can I get a recommendation for a voltmeter?

OBDII codes are all the same no matter what manufacture made the car. The government is responsible for that. I actually pulled those from a Audi website but they are the same.
I use a Craftsman voltmeter at work cause I've had it for years and don't want to buy a new one. A Fluke would be better, they are several hundard dollars. You probably won't need anything to fancy so any decent meter would work, about $100-150. Don't buy the really cheap ones that are $10, they aren't even close to being accurate.
Ok, I decided to look at the alternator area just to see if there was anything obviously wrong.

First off, is there an O2 Sensor in the area of the alternator, opposite it? I read in the Haynes manual that 1 of the 2 sensors is in the exhaust manifold but I can't tell from the shielding what this thing is sticking out of. It kinda looks like a spark plug, shapewise. Anyway, if it is, the braided line running to it is frayed at the end. Looks like a stress seperation instead of normal wear.

Also, there's 3 rubber looking lines in the power steering pump area that head downward in the alternator's direction. They look like seperate lines but as I was poking around noticed they were stuck together. I don't believe they were supposed to be together so I put some minor pressure on the obvious power steering pump line using my pointer finger and thumb and they seperated but it looks as though some of the rubber jacket on the other 2 lines came off. I used the 2g DSM Engine Bay Visual Aid and didn't see these 2 lines in the pics.

Any thoughts? TIA
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Yea the first o2 sensor should be behind the alternator/PS pump area. It is sticking out of a heat sheild, should be a 4 wire sensor. If there is bare copper wire showing through then you need to fix it, probably get a new sensor. But you might just be looking at a heat sheild/wrap that goes around the wires.
Also your code was for the post cayt o2 sensor. So you might want to jack the car up and look at it, should be midway down the car on your exhaust, it's a little after your cayt converter.

I don't know about the 3 lines you were talking about, I'll try to look at my 2gen tommarrow, hopefully.
Ok, I'm getting under the car this weekend. I'm on a mission :D. I looked at the lines this morning in better light...because my car was reluctant to start. There's a line that goes from the PS Pump to the Alternator and meets up with 2 other lines that head into the alternator. Upon closer inspection they don't look to be bare. I believe if anything I disturbed some crusty dirt on them. Now I'm starting to think that maybe it's the starter cause of the problems I'm having with cold starts. It's baffling!

Last night, leaving the gym, I start the car and it did the dim thing. I gave it a few high revs, which normally cures it...nothing. So I decide I'll pull out of my spot and get some running room and put my foot all the way down. It was a mild acceleration compared to when it's not dim. Still nothing. So I'm barely cruising out of the parking lot wondering what I should do when the lights decided to go from dim to full-on as if I was using a dimmer switch. It wasn't instant, just a very quick transition from dim to full lit, all while more or less sitting still.

I hope I find something with the 2nd O2 cause this is driving me nuts.

Thanks for all the time and effort you've been putting in for me Big Red. I really appreciate the help and have new found aspirations to be able to do all my own work.
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