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

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.

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.

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.

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.

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".

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.

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?

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.

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.

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".

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

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.

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.

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.

Yes maybe you can get a free battery!

 

I have that same Actron. That P1103 code description is not correct for Subaru.

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?

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.

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)

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.

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.

G, I guess most of us agree

 

see post #11, #12 and #19

 

on not doing this procedure.

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.

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