06 TL Voltage drop when warm out
02-24-2017, 09:06 PM
#1
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06 TL Voltage drop when warm out
Ok so I'm not sure whats going on here. 06 TL A/T bout 110k. I noticed the other day when the temps shot up above 50 degrees out outside that my radar was showing 12.4V while sitting at a light. Once I start moving again it returns to normal at 14.2V. It will also go back to normal if the car is not in gear. At first I thought it was the accessory outlet not giving proper voltage so I put my fluke on the battery and got the same results. Temps dropped to typical NY winter temps and the car has been fine for weeks. Yesterday it went into the 50s again and its back at it. I had a 92 accord back in the day that had issues like this but it just wouldnt start. My TL operates completely normal just has low voltage while in gear and not moving.
First thing I did was have the battery and alternator checked. Battery and alternator were fine. Alternator barely dropped under a load and the ripple was so small it was barely noticeable. Also the alternator is hot but not overheating( as in it sits right by the motor and fans so its hot at operating temp but you can still touch it and cant cook an egg on it. Battery cables are tight and very clean.
I thought it might be the belt seeing as it would occasionally squeal on cold start when it was damp out. I replaced the belt and the squeal is gone but nothing else has changed.
Anybody know what I'm dealing with here? Please help!
First thing I did was have the battery and alternator checked. Battery and alternator were fine. Alternator barely dropped under a load and the ripple was so small it was barely noticeable. Also the alternator is hot but not overheating( as in it sits right by the motor and fans so its hot at operating temp but you can still touch it and cant cook an egg on it. Battery cables are tight and very clean.
I thought it might be the belt seeing as it would occasionally squeal on cold start when it was damp out. I replaced the belt and the squeal is gone but nothing else has changed.
Anybody know what I'm dealing with here? Please help!
02-25-2017, 02:15 PM
#2
Racer
AH, I see you had the exact same issue I was worrying about after I had installed my headunit with a built in volt meter.
Basically, I did some research on the topic and this is NOT an issue with anything electrical on the car if you're battery and alternator are reading good. What Honda has done with these cars is put in a Electrical Load Detector (ELD).
Here's a quote from my thread awhile back:
"Basically all Honda's made since the mid-90's use an Electrical Load Detector (ELD) that sends a signal to the PCM to turn the alternator on or off depending on the charge detected on the battery. So when the PCM senses the battery is charged to full, it will stop running the alternator and voltage on the battery will drop to 12.0-12.6 during normal driving conditions. This measure was put into place by Honda to help with fuel economy.
With the volt meter on my HU, I was initially concerned with the voltage drops because I never saw anywhere below 13.4 on my old car even with my sound system running full power. Since the head unit is based on ignition power and feeds into the ELD and the aftermarket system is drawing right from the positive terminal on the battery, the ELD does not detect the extra load from the sound system on the battery and continues to function as normal. There are ways to bypass this, but when I looked at it, it required splicing factory wires and I do not want to start doing that. The most I was willing to do was cut the metal in my door panels to fit my aftermarket 6.5" woofers and run the wires through the factory door loom.
Hopefully this information will help someone down the line. My alternator seems to be good, when it IS running, I get a solid 13.8-14.1V. My battery is essentially a brand new AGM battery."
Here's a quote from TurboNut who did some research into what triggers the ELD and the voltage drops:
"^ Got to say you are correct in that the Acura has the ELD in the box. Thought only the "old" Hondas had
the ELD, so had to do some research.
Looks like the LCD will hold voltage at 12.4/12.9, and only if all the following conditions are met:
Electrical load below 15 amps
Vehicle speed between 10-45 mph or in drive at idle
Engine speed below 3,000 rpm
Coolant temp >167 degrees F (75C)
A/C switch off
Intake air temp above 68 degrees F (20C)"
As you can see with TurboNut's answer, it would make snese that you are noticing the issue more when the weather is warmer because some conditions that trigger the ELD are met by engine temperature related items.
Hope this helps. I would say your car is good, it's just standard operating for the voltage to drop.
Link to my thread: https://acurazine.com/forums/3g-tl-p...-drive-951331/
Basically, I did some research on the topic and this is NOT an issue with anything electrical on the car if you're battery and alternator are reading good. What Honda has done with these cars is put in a Electrical Load Detector (ELD).
Here's a quote from my thread awhile back:
"Basically all Honda's made since the mid-90's use an Electrical Load Detector (ELD) that sends a signal to the PCM to turn the alternator on or off depending on the charge detected on the battery. So when the PCM senses the battery is charged to full, it will stop running the alternator and voltage on the battery will drop to 12.0-12.6 during normal driving conditions. This measure was put into place by Honda to help with fuel economy.
With the volt meter on my HU, I was initially concerned with the voltage drops because I never saw anywhere below 13.4 on my old car even with my sound system running full power. Since the head unit is based on ignition power and feeds into the ELD and the aftermarket system is drawing right from the positive terminal on the battery, the ELD does not detect the extra load from the sound system on the battery and continues to function as normal. There are ways to bypass this, but when I looked at it, it required splicing factory wires and I do not want to start doing that. The most I was willing to do was cut the metal in my door panels to fit my aftermarket 6.5" woofers and run the wires through the factory door loom.
Hopefully this information will help someone down the line. My alternator seems to be good, when it IS running, I get a solid 13.8-14.1V. My battery is essentially a brand new AGM battery."
Here's a quote from TurboNut who did some research into what triggers the ELD and the voltage drops:
"^ Got to say you are correct in that the Acura has the ELD in the box. Thought only the "old" Hondas had
the ELD, so had to do some research.
Looks like the LCD will hold voltage at 12.4/12.9, and only if all the following conditions are met:
Electrical load below 15 amps
Vehicle speed between 10-45 mph or in drive at idle
Engine speed below 3,000 rpm
Coolant temp >167 degrees F (75C)
A/C switch off
Intake air temp above 68 degrees F (20C)"
As you can see with TurboNut's answer, it would make snese that you are noticing the issue more when the weather is warmer because some conditions that trigger the ELD are met by engine temperature related items.
Hope this helps. I would say your car is good, it's just standard operating for the voltage to drop.
Link to my thread: https://acurazine.com/forums/3g-tl-p...-drive-951331/
Last edited by NoTLoud; 02-25-2017 at 02:19 PM.
02-27-2017, 04:53 PM
#3
2nd Gear
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I can see that but when the car is in park it runs at 14,2V but then its in drive with my foot on the brake it then runs at 12.4V and then goes to 14.2V when I start driving. Wouldn't it drop off when I was driving at speed?
02-27-2017, 05:08 PM
#4
Racer
Yeah, you're only going to notice the voltage drop while in drive. If you never want an issue with voltage drop, you can drive with your headlights on or AC/heat. If the headlights and/or Ac/heat are on, the ELD will never kick in.
If you get your car above 3k RPM, the voltage will jump right back up.
The ELD doesn't look to do anything unless the car is in Drive AND it meets all of the conditions listed above.
You're most likely only noticing it when it's warmer because of the coolant temp requirement. I haven't really paid attention or worried about it after this information was presented to me.
If you get your car above 3k RPM, the voltage will jump right back up.
The ELD doesn't look to do anything unless the car is in Drive AND it meets all of the conditions listed above.
You're most likely only noticing it when it's warmer because of the coolant temp requirement. I haven't really paid attention or worried about it after this information was presented to me.