1998 Cadillac SLS DTC P0303, P0101, P0103

Tiny
TDC
  • MEMBER
  • 1998 CADILLAC SLS
  • V8
  • FWD
  • AUTOMATIC
  • 65,000 MILES
DTC P0103 current, P0101 current, P0303 pending, 2 weeks ago the car was stalling after 5 minutes driving. Check oil light and service engine soon light came on. Checked owners manual and it said that when it was 1 quart low the check oil light would come on, but it was 2 quarts low? I added 1 quart of Lucas engine oil stabilizer and one quart of mobil 7500 15w30. I read that the Northstar engine is very durable, but could driving around 1-2 quarts low hurt anything. Why didn't the check engine oil light come on after it was 1 quart low? After filling the oil just to the full line, I test drove the car to make sure it was ok. I drove it real hard because I wanted to make sure it drove just as well as it always had before. At first the tranny was sluggish. After a while the tranny was working smooth and the overdrive started working as usual. Car was driven normaly the next day for local trips. Then the next day after that I tried to start the car but the battery was down to 10 volts or less with no interior lights at all. I might have left the interior light on overnight, but the owners manual said that there is an automatic shut off after 10 minutes for the interior light in case it's left on. I tried to charge the battery with 10 amps at the proper + and - connectors under the hood but the battery chargers needle would go haywire (as soon as I connected the battery chargers - connector to the - bolt terminal ) and all the way to the right as if the terminals were connected backwards? But they weren't. It ook a long time to undo the situation by making a better contact at the - bolt terminal and finally the battery chargers guage needle slowly went towards the middle of its guage reading and started to charge the system. After 30-45 minutes of charging the car was finally able to start. I never figured out how the battery got so discharged and it hasn't happened again. The service engine light was still on from the 2 days before. The car was driven normaly just some small trips here and there for the next 2 days. Then the mil light went out and has not returned. I went out and got an dtc code only scanner. It now shows the codes listed above. I noticed that the mpg reading on the dash info center was way under 10 mpg, the car is not idling as smooth as it used to, and that the exhaust is not as clean as it used to be. The car starts up ok, is idling sort of ok, has full power at all rpms. You can hear or feel that #3 cylinder missing a samall amount, it affects the smooth idle. What is probably setting off the dtc P0103 and P0101? I have never worked on a late model car and would like to replace or repair the part or parts with the least amount of diagnostic testing. There is so much testing with the mass air flow circuit. Since it's a high reading does that point to something else causing that reading or could the maf sensor need cleaning or replacing? Could the P0303 condition be causing the P0103 and P0101 to set. If I check spark plug 3 do I have to torque it when I put it back. Can I replace just that 1 plug. I've never taken the plastic engine cover off before. Is it easy to get to the mass air flow sensor after the engine cover is off? Which is the correct spray cleaner. Is a q-tip with alcohol also ok to clean it. Does it need cleaning with a high reading or only when their is a low reading. I read about water getting in somewhere or vacuum leaks causing this problem. Could all of this be from the battery losing it's power and the PCM losing all of it's settings? Will this fix itself after the PCM resets itself after driving without any repairs? The owner of the car took it to an auto mechanic to ask about a needed inspection. He saw the engine light and ran the code scanner and was saying a few hundred for this and a few hundred for that, and more. We can't afford the mechanics charges now. We don't want to pay to replace parts that can be cleaned, adjusted, or repaired. I read somewhere about a 2001 Chevy and it was recommended to work on the P0303 first before working on the P0101, P0103. What about testing that all the connectors are on tight and have clean contacts? Are there any connectors that would cause a problem if they were disconnected to check them with the car on or off affecting the PCM? Can I get to the bottom of this problem without using a scantool such as elm 327, volt and ohm meters, air pressure testers, oscilscope, etc, etc. I have a digtial multi meter. I read somewhere that an analog meter or osciliscope might be needed for some of the MAF tests. This is too much for me because I can't get into a complicated time consuming project in a small driveway. Can I get somewhere with fixing this problem without all of the scanning, volt, ohm, etc. Tests.
Do you
have the same problem?
Yes
No
Friday, September 19th, 2008 AT 9:38 PM

7 Replies

Tiny
JACK42
  • MEMBER
That engine holds 8-10 quarts of oil, being low 1 or 2 isnt going to hurt it. Might have a low oil level sensor going bad and it didnt read it, but I though it hads to be more than 1 quart low before it would come on. The codes, they sell a MAF cleaner that is a spray, I would try that to see if it helps. Sometimes they need to be replaced, they just short internallly. You can check for vacuum leaks by carefully spraying carb cleaner around theintake area to see if the idle changes, this would indicate a leak. Also chek the fuel pressure regulator. It is on the fuel rail (where injectors mount to) and has a vacuum line to teh intake, remove th evacuum line and see if fuel is present, if so replace regulator, this will effect mixture and performance and can cause misfires. Has the car ever been tuned up? If not mighht want to start with a tune up (A/C Delco parts) or you can try repllacing just #3 plug to see if it makes the miss go away. ALso warm th eengine up adn use your meter to measuer teh resistance across the #3 injector and compare it to the reading for others to see if it is bad. Usually A MAF problem will create random misfires P0300, usually not specific ones P0303. So go after the misfire, then try cleaning the MAF sensor
Was this
answer
helpful?
Yes
No
Saturday, September 20th, 2008 AT 7:53 AM
Tiny
TDC
  • MEMBER
Your advice is very helpful because I need to plan what to do before taking off the engine cover and it all made alot of sense.

If there was a problem with the fuel pressure regulator wouldn't that set a P0300 and not just a P0303, because the fuel pressure regulator regulates the fuel pressure equally to all of the 8 fuel injectors, so why would it only affect cylinder #3?

The fpr test is done with the engine running, and there should be no sign of fuel anywhere in or at the end of the fpr vacuum line when it is removed, right?

With the engine running and the fpr vacuum line removed, what happens to the fuel delivery as long as the line is off. Will the car stall as soon as the line is removed or just run rough?

With the carburator spray vacuum leak testing, would the idle rise or lower if a leak pulls in the spray, and is the idle changing because the spray temporarily stops the extra air from getting in to the intake or because of the carburator spray going into the the leak area and then into the intake and mixing with the air and gas?

Wy did the battery discharge overnight down to 10 volts if it says in the owners manual that the battery would shut down after 10 minutes to prevent a battery discharge if the lights were left on. Could it be that someone had left the out door lights on and that thery are not covered in the battery shutoff system, that only the interior lights are covered in the automatic battery shutdown system? I asked the person who drovew the car the day before and they couldn't answer whether they had left the lights on the night before. When I got in the car and there was no electric power I might have shut off the sliding interior light switch
which might have been all the way to the right which the always on position.

Was any kind of electrical damage done by the following incident.

After adding 2 quarts of oil the car was driven normaly the next day for local trips.

Then the next day after that I tried to start the car but the battery was down to 10 volts or less with no power available for any of the interior or outside lights.

The owners manual said that there is an automatic battery shut off after 10 minutes for the interior light in case it's left on. I tried to charge the battery with 10 amps at the proper + and - connectors under the hood but the battery chargers needle would go haywire (as soon as I connected the battery chargers - connector to the -bolt terminal ) and all the way to the right as if the terminals were connected backwards? But they weren't. It ook a long time to undo the situation by making a better contact at the - bolt terminal and finally the battery chargers guage needle slowly went towards the middle of its guage reading and started to charge the system. After 30-45 minutes of charging the car was finally able to start. I never figured out how the battery got so discharged and it hasn't happened again.

This is the part I am concerned about.
When I first hooked up the battery charger it was taking a charge and the battery charger guage needle was in the middle indicating a battery that needed a half hour 10 amp charge to get the car started. So I sat in the car while the battery was charging at 10 amps.

After a while the lights were working again, so I turned on the key to check the battery volts info.
With the key on the A/C kept turning on by itself and I kept shutting it off because it had never done that before. There was also a strange sound coming from the upper left of the dashboard that sounded like an intercom and there was a staticy intercom kind of bell/buzz sound that I've never heard before. Every time that I turned off the key and then turned the key on the A/C would turn on to auto A/C. Thats not supposed to happen.

So after a while I went to check the battery charger and it was running, it was on and the guages needle was all the way to the right instead of in the middle or towards the left. That's what usually happens if you touch the 2 battery charger terminal clips together, causing a big spark, and then the charger will shut down. If the battery
charger is plugged into ac and the fuse shuts down
the charger the guage needle will go all the way to the left. So the charger was on and acting as if the 2 terminal clips were touching, but the battery chargers fuse was not turning off the battery charger. This battery charger shutdown will happen if the clips are not quickly seperated after they are touching and sparking.

There was power to the car for the lights, air, etc with the faulty battery charger guage reading connected to the + and - bolts.
When I removed the faulty battery charger hookup there was no more power to the car at all. So all that time the battery had not been charging with the faulty charger hookup but there was power for the lights, air, etc during trhat time.

So the battery chargers terminal clips were hooked up to the cars + and - jumper connections correctly, but the battery chargers guage needle was incorrectly all the way to the right as if the 2 battery charger terminal clips were touching, but the battery charger was continuing to run for a while instead of shutting down like it normally would.

This was happening while I sat in the car waiting for the battery to charge, after I had first hooked it up and the battery chargers guage needle was where it was siupposed to be, in the middle of the guage.

I then kept unhooking and hooking up the battery charger terminal clips to the same + and - jumper termninals trying to get a proper reading from the battery chargers guage which would be towards the middle of the guage. I tried many times, but everytime there would be a big spark at the - jumper bolt and the battery chargers guage needle
would go super fast all the way to the right.

I kept unhooking and trying again. Then I gave up and was sure that the car was now disabled with some kind of shorted out wiring or electrical component.

I got out the owners manual and was reading alot. I checked out as many fuses as I could and they were all ok.

Because this all didn't make sense, I kept trying to hook up the battery chargers clips to the + and - jumper bolts. The - bolt was sparking alot and the needle was all the way to the right. Then I started to grind the - terminal clip all around the - bolt and after a while the battery chargers guage needle slowly climbed to the middle of the guage and then it sdtarted to charge the battery and the car started 30-45 minutes later. The battery has since not discharged.

Why did the battery discharge down to 10 or less volts overnght even if the lights were left on if there
is a discharge battery save system.

Why did the battery charger do all of that faulty hookup and guage readings without shutting down for 15 minutes? What was that strange intercom sound coming from the upper left side of the dashboard and why was the auto A/C turning on all by itself everytime the key was turned on during the faulty battery charger hookup.

I only realized yesterday that the strange symptoms of the auto A/C coming on by itself everytime the key was turned on and that strange intercom sound from the upper left dash, which I've never heard before in this car was becuse of that faulty battery charger hookup. After the car was charged normally those 2 symptoms went away.

But there is this clicking sound that has started from the right side of the dash or from the right door or right side rear view mirror and it continues to make this clicking sound.

What damage if any could that 15 minute or more faulty battery charger hookup to the jumper bolts have done to any part of the electrical system.

Could it have damaged the MAF sensor or the electrical connection to any of the fuel injectors or to the pcm etc, etc. I read those codes a week after the battery needed charging.

Could this charging incident have brought on the conditions that then set off the 3 codes?

Could there be damage to anything electrical after that faulty charger hookup with the needle all the way to the right with the charger continuing to run and the fuse not shutting the charger down the
whole time?

What caused the battery charger to not just be able to charge the battery at the + and - jumper terminaals succesfully, right from the start?

Did this happen because the battery was in shutdown mode when I tried to charge the battery.
If yes, what was the right way to go about reactivating the battery and then rechargeing
it, and why did the system act or react this way to a
simple battery charger hookup that was hooked up correctly?

Is the electrical system protected from this kind of faulty battery charger hookup?

With the faulty battery charger hookup and/or the charger guage reading described above and the charger running all that time, was the battery charger sending a 10 amp electrical current to places where it normally wouldn't or shouldn't, because of the battery being in shutdown mode and could that have damaged any electrical wires, connections, components, etc?

Be as technical as you want, I just got a pc pda and will soon get an elm 327 scanner to go with it, I will probably get a vacuum guage, and maybe a fuel pressure guage, etc.

Thanks
Was this
answer
helpful?
Yes
No
Sunday, September 21st, 2008 AT 1:41 AM
Tiny
JACK42
  • MEMBER
What you said about the P0300 with the reg is exactly what I said, it would set P0300 "random misfire" not a specific one P0303. Yes the vacuum line to the reg shouldnt have any fuel in it, if so replace it. The engine will change a littel bit from the line being unhooked if you do it with the engine running, but to check for a blown reg you can do it right after you shut it down.I fit is blown, fuel wiill still be there. The only thing that hapens when you unplug it running is that the fuel pressure jumps up a litte bit (around 5 psi) , the reg thinks you are on the throttle by the lack of vacuum to it, so pressure is mechanically increased a slight amount. The vacuum leak you create by unplugging it isnt enough to stall the engine.Carb spray will change the quality of the idle if sprayed on a leak due to the fact you are changing the mixture.The battery.... IF the switch is manually turned on, the body controller cant turn it off.Even with battery run down protection, that is considered domelight over ride.Caddy's go through batteries anyway... there isnt a car out there with more stuff running when the car is off than a Caddy.The battery might even be shorting internally, which caused your charger to read like it did. If hooked up correctly, I seriously doubt you did any damage to any computer parts (MAF) it would damage the PCM first, and the newer cars are much more protected than the older comp controlled cars.You may want to check the condition of the cables, the GM side post batteries had a tendency to leech acid down the cables which ruined them internally, happened on alot of cars. If you are interested in how all of your cars systems work, I suggest you go here

http://www.2carpros.com/articles/mitchell1eautorepair-car-repair-manuals

Same software I have and shows everything about your car and how to do pinpoint diagnosis, use the onboard computer diagnosis system....everything
Was this
answer
helpful?
Yes
No
Sunday, September 21st, 2008 AT 8:50 AM
Tiny
TDC
  • MEMBER
I just read about the battery discharging and the ECM having to relearn all of its settings.

Could that have changed the ECM adjustment instructions to all engine performance sensors, controls, components, etc, and with that then resulting in incorrect readings back to the ECM, which then set off the 2 MAF codes. Could this have maybe even brought on the pending P0303 because #3 was prone to missfire, but not doing so yet, until the ECM lost all of its optimal settings and that then finnally brought on the #3 mosfire? The 3 codes listed were read days after the cars battery was discharged and recharged.

Here is what the article said:
The ECM found in General Motors cars has the capability to learn or modify it's programming with regard to differing fuel requirements over time. Its a complex computer and it can adjust to different conditions easily. It learns while you drive and doesn't forget when you turn your car off either.

But, if you ever change your battery, or your battery goes dead for any reason, your computer will lose it's stored memory and will have to relearn everything. It's a quick learner, but it's something
you don't really want to go through all the time.

Since the battery was totally discharged, could it have anything to do with the codes being set off because of it's affect on the ECM losing all of it's settings? How long does it take for the ECM to recover from the battery discharge? What are the actual affects this has on the cars performance or on any part of the car.

Are the ECM and the PCM the same thing?

How can I test if there was any damage to the ECM or PCM, or anywhere else from that shorted battery charge attempt that you helped me out on?

What would be the best or max size CCA battery to replace the battery for the best performance.
Since its under the seat, there may be a certan max WxDxH battery size. Does it have to be side terminals?

Has AC Delco fixed that problem with their newer side terminal batteries? Does it have to be an AC Delco battery or just any good brand.

Thanks
Was this
answer
helpful?
Yes
No
Sunday, September 21st, 2008 AT 9:52 PM
Tiny
JACK42
  • MEMBER
Yes, sort of. ECM is engine control module. PCM is powertrain control module. PCM s a newer version of ECM. Same thing basically, new name. If PCM is damaged, it will usually throw random codes or non existant, maybe not communicate with on-board diagnostics, many different things. Sometimes car wont even run, I wouldnt worry too much about that. Delco claims thaey fixed the problem with their batteries, but you can use any one you may prefer, get a high reserve capacity, depending on where you live cca's may not make as much of a difference, but you will need one specific for you car, due to the fact that there are vents that MUST be hooked up to get the acid fumes out of the car
Was this
answer
helpful?
Yes
No
Monday, September 22nd, 2008 AT 7:30 AM
Tiny
TDC
  • MEMBER
Are those kind of batteries common for late model cars? What % more would it cost than a regular or non vent set up battery.

The dash voltage reader has always read around 13.9 - 14.2 volts with the engine running with lights, radio, and A/C on, and still does give those same readings.

The dash info battery voltage reading after driving with all the accesories on, with the key on/engine off, is 12.0 volts, and I'm not sure if it was always that low. The car starts ok at 12.0 volts.

I've always only checked the dash info battery voltage with the car running because there never was a problem starting this car.

A few months ago after driving around locally, with all accesories on, I shut off the car and was working on something, for around 15-30 minutes with the headlights on, I am not sure if the domelight was on. After that the car wouldn't start. I Had to get a jump, and it started right up after 5 minutes with another car charging it. I didn't keep track of the battery voltage readings at that time.

Does a dash info battery voltage reading of 12.0 after driving with all the accesories on, key on/engine off, show that the battery is ok, or charging ok, or is that sort of low? How can I test if the battery is still ok, or should be replaced,
besides checking out the physical condition of the battery and the cables.

You had mentioned that a battery could be shorted internally. Can that be ruled out if the car starts and runs ok, with all of the accesories on, or can that condition be intermittent, and only show symptoms once in a while? Can a battery have an intermittent partial short?
Was this
answer
helpful?
Yes
No
Monday, September 22nd, 2008 AT 9:50 PM
Tiny
JACK42
  • MEMBER
Has to be vented due to location. Could be intermittent short. Should have sitting voltage of 12.2 or more. Dash shows system voltage and that alt is working
Was this
answer
helpful?
Yes
No
Tuesday, September 23rd, 2008 AT 7:45 AM

Please login or register to post a reply.

Recommended Guides