2007 RDX alternator/battery issue?
04-20-2015, 09:59 PM
#1
AKYPA Owner
Thread Starter
2007 RDX alternator/battery issue?
Hi AZ community,
I am having an issue with alternator/battery on my 2007 Rdx tech, what happens is the battery would suddenly die completely - car won't start, even displays won't come on, nor cabin lights. My wife would drive the car to work, park for few hours then would find its dead... Happened twice already, both times car had to be jumped, then would run ok for a few days... So I assumed its battery, since once jumped the car would charge it and would run ok for some time. Then I hooked up my auto voltmeter to 12v outlet and observed that when accelerating, crusing - when engine under any load, the voltage would drop to 12.5 +-0.3 or so, but when I would stop or shift to neutral the voltage would go back to 14.3 - 14.5 range, that's very strange as per service manual it should be no less the 13.5v. I even tried shift from D to N while crusing and same thing would happen every time - while in D voltage drops to 12.x, shift to N it momentarily goes to 14.x
I've tested the voltmeter in my Mdx, just to rule out possible issues with it and observed constant 14.x readings throughout my 40 min drive, so voltmeter is good.
I'm leaning towards a bad alternator, but want to check with you guys first to see if anyone has epxerienced similar issues or can think of anything else, before I splurge $300+ on a new alternator.
As always thanks guys for input.
I am having an issue with alternator/battery on my 2007 Rdx tech, what happens is the battery would suddenly die completely - car won't start, even displays won't come on, nor cabin lights. My wife would drive the car to work, park for few hours then would find its dead... Happened twice already, both times car had to be jumped, then would run ok for a few days... So I assumed its battery, since once jumped the car would charge it and would run ok for some time. Then I hooked up my auto voltmeter to 12v outlet and observed that when accelerating, crusing - when engine under any load, the voltage would drop to 12.5 +-0.3 or so, but when I would stop or shift to neutral the voltage would go back to 14.3 - 14.5 range, that's very strange as per service manual it should be no less the 13.5v. I even tried shift from D to N while crusing and same thing would happen every time - while in D voltage drops to 12.x, shift to N it momentarily goes to 14.x
I've tested the voltmeter in my Mdx, just to rule out possible issues with it and observed constant 14.x readings throughout my 40 min drive, so voltmeter is good.
I'm leaning towards a bad alternator, but want to check with you guys first to see if anyone has epxerienced similar issues or can think of anything else, before I splurge $300+ on a new alternator.
As always thanks guys for input.
04-21-2015, 10:18 AM
#2
If your alternator is dead, your car would only run for a few minutes after being jumped before sputtering out and dying again. It's possible that it's not providing as much juice as it could be, but I don't think they tend to go out like that - it generally works or it doesn't.
On the flip side, a weak battery will only hold a small charge (sometimes none), yet once running the car should stay running. However a battery can get so bad that it will not pass a current, and that may be what you're experiencing with the voltage drops. I've had one so far gone before that the car would not even jump start.
I'd replace battery first and check all your connections for corrosion, as that's much quicker and cheaper than replacing the alternator.
On the flip side, a weak battery will only hold a small charge (sometimes none), yet once running the car should stay running. However a battery can get so bad that it will not pass a current, and that may be what you're experiencing with the voltage drops. I've had one so far gone before that the car would not even jump start.
I'd replace battery first and check all your connections for corrosion, as that's much quicker and cheaper than replacing the alternator.
Last edited by Tomtwtwtw; 04-21-2015 at 10:21 AM.
05-13-2015, 10:28 PM
#3
I'm having the same problem as you, and hoping its the alternator. I just replaced the starter on my own, which was a pain in the ass, so now this problem comes up. The battery is a Die Hard Gold, but I still need to put it on a voltmeter. I'm also getting the code P0562, pertaining to the Charging system.
05-15-2015, 11:04 AM
#4
AKYPA Owner
Thread Starter
I ended up replacing the alternator and drive belt as well (since had to remove it anyway).
Voltage readings still vary during vehicle operation.
Since then I also came across a forum where another owner discussed same thing and apparently its the way it suppose to work, I also was able to reproduce same on 2015 MDX.
I would guess the voltage regulator (or ECU) when senses that battery is fully charged, drops the voltage to prevent overcharging.
However this is not mentioned in RDX full service manual, and the diagnostics steps state the voltage should be no less then 13.5 when vehicle is running, parked and under load - AC, high beams, etc.
But so far I have not had issues with dead battery.
I am thinking next time (if) it dies, I would just replace the battery.
If anyone has any other ideas/recommendations, please post.
Voltage readings still vary during vehicle operation.
Since then I also came across a forum where another owner discussed same thing and apparently its the way it suppose to work, I also was able to reproduce same on 2015 MDX.
I would guess the voltage regulator (or ECU) when senses that battery is fully charged, drops the voltage to prevent overcharging.
However this is not mentioned in RDX full service manual, and the diagnostics steps state the voltage should be no less then 13.5 when vehicle is running, parked and under load - AC, high beams, etc.
But so far I have not had issues with dead battery.
I am thinking next time (if) it dies, I would just replace the battery.
If anyone has any other ideas/recommendations, please post.
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IIDXholic (06-06-2015)
05-18-2015, 05:20 PM
#5
Not sure about first gen RDX, but the 2nd gen and probably every new Acura now uses that technology.
ENERGY MANAGEMENT SYSTEM (EMS)
The RDX has a new Energy Management System (EMS) that is designed to reduce the chance of a dead battery, increase the overall service life of the battery and help deliver improved fuel economy.
Should a RDX owner accidentally leave on the headlights or not close a door causing an interior light to remain on, after a set period of time the EMS will automatically terminate power delivery to prevent the battery from going dead.
The RDX 3.5L engine makes use of a powerful 130 amp alternator that charges in five different ranges- 12.5-, 13.0-, 13.5-, 14.0-, and 14.5-volts. By closely controlling the alternator charge voltage, EMS works to keep the battery in a specific charge range which can extend the service life of the battery by more than 25 percent. With EMS keeping the battery in a specific charge range, the alternator can run more often in the low range which generates less drag on the engine resulting in improved fuel economy.
Application of numerous electrical power reducing items allows the EMS to operate the alternator even more frequently in the more efficient low charge mode.
Should a battery or charging system issue occur, the Multi Information Display (MID) will alert the driver with a text prompt such as, "CHECK CHARGING SYSTEM".
The RDX has a new Energy Management System (EMS) that is designed to reduce the chance of a dead battery, increase the overall service life of the battery and help deliver improved fuel economy.
Should a RDX owner accidentally leave on the headlights or not close a door causing an interior light to remain on, after a set period of time the EMS will automatically terminate power delivery to prevent the battery from going dead.
The RDX 3.5L engine makes use of a powerful 130 amp alternator that charges in five different ranges- 12.5-, 13.0-, 13.5-, 14.0-, and 14.5-volts. By closely controlling the alternator charge voltage, EMS works to keep the battery in a specific charge range which can extend the service life of the battery by more than 25 percent. With EMS keeping the battery in a specific charge range, the alternator can run more often in the low range which generates less drag on the engine resulting in improved fuel economy.
Application of numerous electrical power reducing items allows the EMS to operate the alternator even more frequently in the more efficient low charge mode.
Should a battery or charging system issue occur, the Multi Information Display (MID) will alert the driver with a text prompt such as, "CHECK CHARGING SYSTEM".
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Koreets.RU (05-19-2015)
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