Hello everyone. I am new to the forum, and hoping this community will help me keep my stepson's 2003 Saturn Ion sedan on the road for a while longer. My stepson has been under-employed since the pandemic began, and the car was a gift to him from his grandmother, who recently passed, so any help is greatly appreciated.

He was driving a few weeks ago when the car suddenly lost power and shut down -- in traffic. He was freaked out but able to coast to safety, My wife met him and they jump-started his car, but it died again as he was driving, with his mom following. The car was then towed to our driveway.

I had replaced the battery in June 2020 with a new Interstate unit, Group Size 75, which is well within spec for the car. Nevertheless, I put the battery on my charger, as I figured the battery might be low due to lack of use since the pandemic. After a day on the charger, I sloughed off the surface charge and then used a multimeter to test the battery and the alternator, at the battery terminals, and both battery and alternator tested good. On the dash, though, the battery warning light and check engine light were illuminated when we turned the key, and they did not go out the entire time we ran the car to test the alternator,. My multimeter showed the alternator was putting sufficient voltage back to the battery terminals while the car was running.

I then used an OBDII reader and retrieved the following stored codes:
P 0700 Transmission Control System
P 0562 System Voltage Low

I have read online that the P0700 code means the transmission control module (TCM) may be bad, the transmission fluid might need changing, entire transmission may be bad, or the voltage from the ECU to the to the TCM might have dropped too low for the TCM to handle. The P0562 code obviously suggests the last problem as most likely, although I am aware that the two codes being stored might be coincidental. The car has an automatic transmission, which is shifting normally.

I am not sure if the car is designed to shut down if the TCM malfunctions, But I think that the car shutting down, the two warning lights, and the two codes are all related to a low voltage situation. However, with a new battery installed in June, the battery and alternator testing good, and all of the wiring and electrical connections visible to me looking okay, I am stymied.

My thought is to make sure the battery is charged, clear the codes, and have my stepson drive the car and see if the stalling condition, warning lights, or ECU codes return. However, he is a relatively inexperienced driver, so he is spooked to drive the car without either of us knowing exactly why the car died in traffic. I would drive it for him, but I am not on his car insurance policy and I would rather not deal with that issue if it can be avoided.

The car has been sitting in our driveway for several weeks and he has relied on friends to get around. I am looking for advice as to what to do next.

FWIW, I have still mages of all of the OBDII readouts at idle, and video of the readouts with the engine revving. I don't know if they can supply any relevant information, but I can try to post them if they are important.

 

Charge light on the dash almost always means the that the battery is not receiving a sufficient charging from the alternator. The question is why not. Or that the battery cannot store charge.

Either your alternator is dead and not putting out current to charge the battery, or you have a bad or corroded connection between the alternator and the battery. If there is a fusible Link in line between the two, that can also have burned out. Or the battery may have lost a cell. Can happen with a brand new battery so don't discount it.

Check the wiring first and clean up the connections at both ends. Ensure the battery end of the positive cable has not wicked up a bunch of battery acid. Cut the plastic insulation back a few inches. If it is crunchy get a new one.

While you are at it, make sure the feed from the battery to the underhood junction block is not crunchy and that the connections are clean at both ends. A poor enough connection acts like high resistance in the circuit and hence there is a significant voltage drop across the cable and connections, and the voltage actually seen by the PCM is much lower than 14.4.
That system voltage low code is the PCM saying I need a higher voltage and associated current to run properly or I'm going to puke.
If you read 14-4V on the output connection at the alternator.and 14-4 v at the connector to the battery not the terminal, (both with respect to chassis ground), the cable and connections are probably okay. It then comes down to whether you're alternator is putting out any current or whether your battery cannot store the charge. From your explanation I would have to guess if it is not a wiring issue then your alternator is not putting anything out current wise.

Get the battery nice and charged up and take it to AutoZone or similar and have them do a charging system load test. This should quickly identify the issue.

Hell, let it idle in the driveway. When it stalls check the battery voltage. I'm thinking it will stall If the alternator is not charging the battery because the car will then be running off the battery and when the voltage gets too low everything just stops
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P0700 is a generic code that tells the PCM that the TCM has transmission codes stored. That is the sole purpose of this code. It has by definition no information about the nature of what is going on with the transmission. Sometimes it is accompanied by other p07xx codes, depends on the vehicle.

To find out what is going on, you need to use a scanning tool that can access the TCM to read the transmission codes.

 

Welcome. What was the voltage reading running? It has to be 14.2-14.5 volts at idle with no electrical load. If it is less than 14.2 volts you you either have a battery that will not take a charge or an alternator not working correctly.

 

I recently ran into this with a 2006 dodge stratus giving me a system low voltage and a transmission code.

Granted its a dodge and not a GM. But have the battery load tested. I did exactly what you did and it still ended up being the battery (but the difference was that battery was 3 years old)

Check your grounds as well just to cover all bases. Havent seen it often in the ions, but with the chevy cobalts (sister car) theyre known for randomly shutting off due to grounds coming loose or breaking over time

 

Voltage running was 14.5

 

Interesting. Even though the battery is fairly new, and the car had not been sitting for more than a few weeks before this problem developed, a neighbor suggested the battery might be defective. He thought having it load tested or just returning it to Costco for an exchange might be my next step.

But would a bad battery cause the car to shut down? To be clear, it did not stall out; it just lost power all at once. I am guessing it’s possible a battery with a bad cel or other internal fault of some kind could cause a low voltage condition, tripping the transmission control module and causing the car to shut down as a kind of fail-safe mode, but I just don’t know. Did your Dodge shut down while being driven?

I am not sure where the grounds are in the 2003 Ion. I understand there is one in the trunk with the battery, and one in the engine bay. Is that right? Is there also one on the alternator?

 

The dodge wouldnt shut down while driving. But held those 2 codes until I put a new battery in it.
there is 1 ground from behind the driver side head light to the block. And a couple that come off the wiring harness.

My personal Ion, I added a few more grounds to. Just from block to chassis.

No battery light before it shuts off?

 

I wasn't driving so I don't know... but I will ask.

In the meantime, I uploaded the full OBDII report to here. Maybe it shows something else; something that I am missing:
This link is to the OBDII data: https://drive.google.com/drive/folde...TS?usp=sharing

 

That's funny. I believe a few of us already suggested the possibility of the battery being the issue and to get it load tested.

With a computer controlled vehicle, if the battery's not holding a charge, when the voltage gets low enough, the computer cannot run.

Technically we are talking about storing charge with which relates to current, not voltage, but you need to have enough current at the correct voltage to operate properly. If the computer cannot run, the engine cannot run. So yes it will just flat out stop. Just remember there's been a long lead up to that event so it should not be unexpected that this is the ultimate result.

Leave your odb2 scantool attached and select to monitor the voltage input at the PCM or ECM. If the battery is not holding a charge, you will see the voltage slowly but surely drop.



Did you get the load test done? Have them do the entire system. If your battery is bad, replace it then have them do the test again to make sure your alternator is putting out a healthy current

​​​​​ New battery is a misnomer. It maybe new to you but may be old stock from 2 years ago. Shouldn't discharge that much sitting on the shelf with no use but cells can go bad.

 

Do you know how to check the date on a battery? Some (not all) have a round decal on them with two numbers on it. For example 07-19 would mean you have a battery that was new in July of 2019. If you had 04-20, that would be April of 2020. What does yours say?