FrankDux Posted February 18, 2008 Share Posted February 18, 2008 1997 Legacy 4wd Wagon, 116k miles, poorly maintained, no major mechanical work, one month old battery. My subaru's electricity cut out yesterday for the first time with and ODB II code of P1103 "Manufacturer controlled fuel air mixture". The sequence was: While driving: - Auto windows stopped responding - Radio cut out - Lights faded - Sounds of power cycling and sputtering While idle at a stop: - Engine sputtered and stopped Had it jumped twice, it failed both times when disconnected from the jumper battery. Second time ran it connected to the battery and engine rev'ing for 15 minutes. Second time if failed 2 minutes later while driving downhill and applying gas. Thanks everyone in advance, Frank Quote Link to comment Share on other sites More sharing options...
Cougar Posted February 18, 2008 Share Posted February 18, 2008 It sounds like the battery is either bad or it is discharged. I suggest you see if it will charge up before trying to run it again. The alternator most likely has a problem also and isn't charging the battery as it should. Quote Link to comment Share on other sites More sharing options...
FrankDux Posted February 18, 2008 Author Share Posted February 18, 2008 It sounds like the battry is either bad or it is discharged. I suggest you see if it will charge up before trying to run it again. The alternator most likely has a problem also and isn't charging the battery as it should. Great suggestion, I will get it fully charged tomorrow and repost results. Quote Link to comment Share on other sites More sharing options...
94Loyale Posted February 18, 2008 Share Posted February 18, 2008 I would bet on the alternator by the sounds of it. But since it wasn't charging, it discharged the battery like Cougar said. Take the battery out and charge it up full. Then put it back in and see if you can get it to run. When it's running, disconnect one of the battery leads, if it dies, its probably a bad alternator. Quote Link to comment Share on other sites More sharing options...
Durania Posted February 18, 2008 Share Posted February 18, 2008 Don't drive too far from home after you charge battery up or you will end up calling tow truck, I've been there. It takes just a matter of minutes to change an alternator. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted February 18, 2008 Share Posted February 18, 2008 Hi FrankDux and welcome! It does sound like a potential alternator issue. Are your battery cable connections and alternator connections tight and the alternator/ps belt is in good shape? What voltage do you read at the battery terminals with the engine idling? Also yes if your battery is low, it's not a bad idea to let it slow charge (1-2 amps) overnight before starting; no sense over burdening the alternator. Car starting batteries do not like being discharged too far especially not multiple times, so it may have spanked your battery as well. For ODBII, codes starting with P1 and P2 are manufacturer and model specific, so descriptions found in various lists/books/generic code readers might not be right for your vehicle. When I look up P1103 in a typical soob ODBII list it say "P1103 Pressure Sources Switching Solenoid Valve Circuit". Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted February 18, 2008 Share Posted February 18, 2008 Even though your battery is just a month old, it may be low on water. Take care in prying off the battery caps to check the water level. (It is easy to splash battery acid on your clothes. My jeans with holes can attest to that.) I have purchased batteries in the past that have been low on water when new. I never bothered to check their water level, thinking if new, the battery must be full of water. That is not necessarily so. It is worth looking into. Quote Link to comment Share on other sites More sharing options...
Bigbusa Posted February 18, 2008 Share Posted February 18, 2008 Take the battery out and charge it up full. Then put it back in I'd just charge it in the car. Why take it out, charge it and then put it back in? Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted February 18, 2008 Share Posted February 18, 2008 It scares the battery into taking a charge. When it is taken out it thinks it might be ready to be turned in as a core so it figures it better shape up. Quote Link to comment Share on other sites More sharing options...
Skip Posted February 18, 2008 Share Posted February 18, 2008 When it's running, disconnect one of the battery leads, if it dies, its probably a bad alternator. This a highly questionable proceedure. With the computers on board a voltage spike caused by this can cause "brain damage". I for one do not recommend this. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted February 18, 2008 Share Posted February 18, 2008 Good catch skip. Yes Subaru does not recommend pulling a battery cable with the engine running. The literature says something like "a large counter emf will be generated by the alternator which could damage the ECU and other componenents". Quote Link to comment Share on other sites More sharing options...
FrankDux Posted February 19, 2008 Author Share Posted February 19, 2008 Hi everyone, thank you for the warm welcome and helpful suggestions. The alternator was only reading at 10.5v. The battery would not hold a charge from an external charger. I put in a new alternator today. Same experience with the new alternator, 10.5v reading at the battery. I'm pulling my OBD code description from the reader itself, it provides the text description "Manufacturer Controlled Fuel Air Metering." I checked the end caps, connectors, and belts and everything seems properly in place. Best, Frank Quote Link to comment Share on other sites More sharing options...
Durania Posted February 19, 2008 Share Posted February 19, 2008 Just take the battery back. I have found that batteries can have bad batches just like everything else. Most places won't give you too much crap about taking it back. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted February 19, 2008 Share Posted February 19, 2008 Could be a bad cell in the battery. I had one with a bad cell and even fully 'charged' it was ~10.5V. On P1nnn and P2nnn codes the generic code reader descriptions are not always correct since the code meanings on P1 and P2 vary between manufacturer. Quote Link to comment Share on other sites More sharing options...
FrankDux Posted February 20, 2008 Author Share Posted February 20, 2008 Could be a bad cell in the battery. I had one with a bad cell and even fully 'charged' it was ~10.5V. On P1nnn and P2nnn codes the generic code reader descriptions are not always correct since the code meanings on P1 and P2 vary between manufacturer. Good idea, the battery is still under warranty from AAA, so that should be a free and painless swap. I do like my code reader, a Actron CP9135. It recognizes the Make/Model on the device, has a text description of the error, and a cd database lookup. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted February 20, 2008 Share Posted February 20, 2008 Yes maybe you can get a free battery! I have that same Actron. That P1103 code description is not correct for Subaru. Quote Link to comment Share on other sites More sharing options...
Skip Posted February 20, 2008 Share Posted February 20, 2008 I put in a new alternator today. Same experience with the new alternator, 10.5v reading at the battery. Frank please get back to us when the new bat is installed. I do not like this reading with the new alt in place. If you mean when the engine is running over 1000 RPM. Bad bat or not the alt should have a voltage output closer to 14 Vdc when the engine is running at this speed. Maybe the wiring to / from the alt is also suspect? Quote Link to comment Share on other sites More sharing options...
Cougar Posted February 21, 2008 Share Posted February 21, 2008 The battery has a shorted cell and that is why the charger couldn't charge it. Don't use the battery at all as it could damage the new alternator. I'm sure when you get a replacement the voltage from the alternator will be fine unless damage has already been done to it. Running the alternator on a battery with a shorted cell will cause the alternator to put out full current output to try and get the battery voltage up to a normal voltage level, which it can't do. The continuous high charging current could kill some diodes. Quote Link to comment Share on other sites More sharing options...
aircraft engineer Posted February 22, 2008 Share Posted February 22, 2008 IF you disconnect the battery and the alternator is "good" it won't be after you disconnect it - plus it will throw voltage spike that might take out every other piece of electronics in the vehicle The battery voltage supplies the reference voltage for the alternator - with it disconnected the system goes into "runaway" and the output diodes are the first to go (from over voltage - it CAN go up to over 100v) and then anything else as well bad bad bad get a voltmeter on the system - charging voltage is about 14.5, static voltage is 12.5 or so (depending on battery charge - will be less if discharged). The battery is probably dead - what you need to do to verify it is to pull it out and take it somewhere they can a draw down test of load vs voltage and see the load discharge characteristics just read the later responses - you won't "hurt" the alternator by having it see 10.5V but it won't charge either (the regulator won't like it, though) Quote Link to comment Share on other sites More sharing options...
Cougar Posted February 22, 2008 Share Posted February 22, 2008 you won't "hurt" the alternator by having it see 10.5V but it won't charge either (the regulator won't like it, though) Not true. Running a alternator on a battery with a shorted cell will cause the alternator to have an early death. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 22, 2008 Share Posted February 22, 2008 Take the battery out and charge it up full. Then put it back in and see if you can get it to run. When it's running, disconnect one of the battery leads, if it dies, its probably a bad alternator. DON"T DO THIS!!!!! This is the #1 worst way to try to test an alternator. Have the battery and alternator tested properly at autozone/advance/checker or somewhere that offers testing. If there is a problem with the alternator, you could Destroy you're ECU, or other senitive electronics. The system needs the battery as *ballast* My bet is the battery died. In turn it then took the Alternator with it. Quote Link to comment Share on other sites More sharing options...
Skip Posted February 22, 2008 Share Posted February 22, 2008 G, I guess most of us agree see post #11, #12 and #19 on not doing this procedure. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 23, 2008 Share Posted February 23, 2008 G, I guess most of us agree see post #11, #12 and #19 on not doing this procedure. It was just a knee jerk reaction a soon as I read the suggetion he try it.. I should have finished reading everyone elses posts. Quote Link to comment Share on other sites More sharing options...
aircraft engineer Posted February 23, 2008 Share Posted February 23, 2008 Not true. Running a alternator on a battery with a shorted cell will cause the alternator to have an early death. That's because with the lower voltage the alternator tries to put in as much current "as it can". Failure will happen because of heating the stator wiring (but it's not "immediate" and you SHOULD notice that something is "wrong" and figure out what "broke" ) Charging systems are pretty straight forward Quote Link to comment Share on other sites More sharing options...
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