battery light stays on but running fine

[galactus]

Hello:

I am new to the forum and glad I found it. I have a problem with my 2007 Yaris. The car is running great. No misses, loss of power, etc.
But, the battery light stays on and the running lights stopped working.
I left the car run and unhooked the battery and there was no stalling. It kept idling just fine. It has about 70,000 on it and has been trouble free. I do not want it to leave me sitting somewhere, but for now is OK.

The battery light has been flickering off and on since about 50,000 with no performance issues. But now it stays on and, as I said, the running lights stopped working.

Does anyone have any ideas?.

I know there are codes, but I do not have access to any computers unless I take it to the garage. Which I will probably have to do.

[yaris-me]

You probably need a new alternator.

[galactus]

Thank you for the response. I thought of that, but was hoping not. It may run a while like this and then let me set.

[CTScott]

The daytime running light module (and the A/C computer) have input signals from the alternator. If the alternator output signal is not indicating that it is generating enough output these systems will shut off to keep the important things running (engine and ECM).

Your issue could be the alternator itself or the voltage regulator (a module within the alternator, which generates the signal to the DRL and A/C). It could also be the battery, but you don't mention issues with starting, so it sounds like the battery is fine. There is a small 4 pin connector that plugs into the alternator, which carries that signal. I would check it out first to make sure it isn't loose. The high current feed to the battery is a completely separate wire, so the battery would still charge with that connector loose, but the ECM and ECUs wouldn't know that it is actually charging.

[YarisSedan]

What CTscott said

[WeeYari]

There is a TSB on the voltage regulator. The connectors are subject to corrosion which leads to a triggering of the indicator light.

[galactus]

Thank you very much for the responses. the light is no longer on for the time being. I think it is the connection you mentioned. The Toyota garage wanted $600 for a new alternator whch I do not think it needs. Just checked out and cleaned.

[Starhawk]

many thing could happen to your car, when your battery is weak. Recently, my 2007 Yaris had gas pedal had no power when I stepped on it. When I took to a mecahnic, he suugested me to change the air filter which I did and there was no change on the gas pedal, so he suugested me to take to the dealer, the guy said to me that the technician will need at least an hour to look for any problem. WhenI got home, i got a call from the dealer, he said to me that because I was having an after market remote starter installed in my car, which causes the problem, he said that the Toyota experienced technician will have to check all the wiring, and run them again which he will need another three hours to do so, and each hour will cost me $110.00+ Tax. Which will total about four hours. By evening, I went to the dealer, the service agent said to me that my car had a serious problem, which the technician had to spend more time to check all the electrical wiring and so on, But the tests are ok and the car has power on the gas pedal, and he also told me that the battery is weak and I needed to replace the battery.... It costed me $497.00 and change just for that( istead of saying, we checked the battery and found it was very weak and needed to replacedand if that was the case, it wouldn't have costed me $497.00). I believed that for any problem we have with our cars, and if we take to the dealers, they know what the problem is ,but they just wanted to make as if very hard to find and charge us more.

[sambo42xa]

My 2007 (99k) is pretty much doing the same thing. Only differance: car is running at idle and the battery light flutters not to the point it goes out. While running I remove either battery cable or even both and the battery light stays on and does not flutter (car is still running). Put the cable/s back on and the light flutters again.
With car off I removed the battery cable off of the alternator and cleaned the connection since it did have a little bit of corrosion. The pin plug I removed also but did not see any corrosion. Output on alternator was around 13.8 and the same at the battery. No change after cleaning connection.
From what I have read here, it seems you folks are steering more towards the alternator (internals) than the battery. No problems starting car so I'm pretty sure the battery is fine (13.8 volts). Everything else works fine. Are there any readings on the pins I can check or are we 99.9% sure it is the alternator?
I'm good with mechanics and I'll check/test whatever.
Thnx in advance!
sambo

[CTScott]

My 2007 (99k) is pretty much doing the same thing. Only differance: car is running at idle and the battery light flutters not to the point it goes out. While running I remove either battery cable or even both and the battery light stays on and does not flutter (car is still running). Put the cable/s back on and the light flutters again.
With car off I removed the battery cable off of the alternator and cleaned the connection since it did have a little bit of corrosion. The pin plug I removed also but did not see any corrosion. Output on alternator was around 13.8 and the same at the battery. No change after cleaning connection.
From what I have read here, it seems you folks are steering more towards the alternator (internals) than the battery. No problems starting car so I'm pretty sure the battery is fine (13.8 volts). Everything else works fine. Are there any readings on the pins I can check or are we 99.9% sure it is the alternator?
I'm good with mechanics and I'll check/test whatever.
Thnx in advance!
sambo

The blue wire on the multi pin connector on the alternator is the output to the cluster that drives the indicator. The service manual says that the normal operating range is 11 to 14 volts, so you could measure the voltage on that wire to see if it is fluctuating. The pink wire is a signal to the ECM and AC ECU. Based on the output of this signal, the ECM can tell the cluster to also light the indicator.

There is a TSB for 07 Yaris about a potential internal corrosion issue of the voltage regulator, which can cause the behavior that your are seeing, without actual charging issues.

[sambo42xa]

CTScott- I was just informed this evening from my wife that the Battery Light went out. Though she didn't notice if it was out when she started the car or if it went out while driving.....either way I will take reading/s off of these pins tomorrow and see what I come up with so I know for myself what to look for next time. And this willl help for Others on the forum which is what it's all about, right?
.......too be continued...........
thnx, sambo
southern, nh
30* with intermittent clouds

[roadrunner]

many thing could happen to your car, when your battery is weak. Recently, my 2007 Yaris had gas pedal had no power when I stepped on it. When I took to a mecahnic, he suugested me to change the air filter which I did and there was no change on the gas pedal, so he suugested me to take to the dealer, the guy said to me that the technician will need at least an hour to look for any problem. WhenI got home, i got a call from the dealer, he said to me that because I was having an after market remote starter installed in my car, which causes the problem, he said that the Toyota experienced technician will have to check all the wiring, and run them again which he will need another three hours to do so, and each hour will cost me $110.00+ Tax. Which will total about four hours. By evening, I went to the dealer, the service agent said to me that my car had a serious problem, which the technician had to spend more time to check all the electrical wiring and so on, But the tests are ok and the car has power on the gas pedal, and he also told me that the battery is weak and I needed to replace the battery.... It costed me $497.00 and change just for that( istead of saying, we checked the battery and found it was very weak and needed to replacedand if that was the case, it wouldn't have costed me $497.00). I believed that for any problem we have with our cars, and if we take to the dealers, they know what the problem is ,but they just wanted to make as if very hard to find and charge us more.

Sorry to hear your story. Being that it is a 2007 Yaris battery, it is time to get a new one. That is free info. I still am running my 2007 original battery.

[jamescarruthers23]

i have a problem with my yaris 2006 1.3vvti, the problems all started when a towbar was fitted all correctly by a company, the problems are
>no indicator lights when engine is running ( but work fine on just ignition)
>no heater blowers working ignition or engine running
>air bag light comes on and goes off every now and again
>battery light is illuminated permanently when engine is running

we have checked the alternator output and it vairies from 13.4 to 13.8 volts
we have checked all the fuses and relays
we have fully disconnected all the wires that were fitted with the towbar and still have no ideas

it was fitted with twin electrics on the towbar, one of the caravan leads had been dragged along the floor so it had worn through the cable replaced the cable and plug plugged it in and this is when all the problems started is there anything that could have gone wrong caused by my caravan any suggestions are appreciated as i have had it to a garage and the cannot find any fault with the car and the caravan doctor came out and he can only see it being a shorted battery that can cause anything like this many thanks james

[CTScott]

Did you check both the fuses under the hood as well as the fuses under the bottom of the dash?

I would check the 10A GAUGE fuse under the bottom of the dash, the 40A HTR fuse (on the face of the under dash fuse panel), and the 60A MAIN fuse (which is part of the positive battery terminal).