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2014 G63- OPTIMUS “Grime”😬 battery issue- red battery error
Hi team,
first of all I’d like to thank everyone in this forum . I acquired my 2014 G from a salvage auction and this forum has helped me rebuild it.
i call it optimus Grime out of affection and the fact that fixing it, covered my hands and knees in grime.. ha ha.. I’m kidding.. I’ve enjoyed every bit of it.
current issue is that when I replaced both the main battery and aux battery 3 months ago when I purchased the car. So they’re new. At did stay standing for this time since I was working on it. But I have kept the batteries on trickle charger all the time. It reads 12.6 v before I start ignition . If it turn on lights and stereo before ignition, it drops to 12.05 volts under this load with key in #2 position.
when I finally started driving the car, I got the red battery signal and I noticed a humming inside the car that seems to be coming from the battery compartment. It’s not a squeak or screech— it’s a deep hum and sometimes it’s alternating. I tried to record but the video won’t pick it up.
I am trying to figure out if it’s a battery issue or alternator issue. Battery is easy to replace its under warranty. Alternator- I don’t even know where it’s located .. ha ha.
when I crank it, the voltage drops to 9.58 . Is that too low? Is the battery bad. Once it’s running it goes up to 14.2 v which makes me think that the alternator is charging it up .
I think all he voltages you measured are OK (starters place a heavy load on batteries, hence the dramatic drop). Have you done an OBD scan when the red battery light is lit?
Yes, the voltage measurements you made don't seem to point at a battery issue or for that matter, an alternator issue either. Therefore, I suspect something in the sensing electronics. I had a W212 that would throw a red battery light from time to time even though nothing was wrong with either the batteries or the alternator. If you can access to a Star system or other advanced diagnostic scanner (like the Foxwell scanner) there may be some detailed fault information stored in the system. An OBD scan could be useful to see if there are any pending codes. Also, some scanners have a real time data function and with those you can monitor the car system voltage while driving to see that is staying in the proper range.
Yes, the voltage measurements you made don't seem to point at a battery issue or for that matter, an alternator issue either. Therefore, I suspect something in the sensing electronics. I had a W212 that would throw a red battery light from time to time even though nothing was wrong with either the batteries or the alternator. If you can access to a Star system or other advanced diagnostic scanner (like the Foxwell scanner) there may be some detailed fault information stored in the system. An OBD scan could be useful to see if there are any pending codes. Also, some scanners have a real time data function and with those you can monitor the car system voltage while driving to see that is staying in the proper range.
that’s exactly what it seems like.
I plugged in an OBD2 and it shows no error.
I have a MB star system and I plugged that in as well and it doesn’t read any fault on a quick test.
Whenbi took the car for a drive, no warning came for the first 10-15 min and I thought maybe it had gone away... and then 15 min in the drive it flashed again.. i happened to have the mastar system plugged in and it showed a battery voltage of 14.7 at that time.
it’s not humming all the time. It just hums and makes that groaning sound once a while.
I have attached some pictures to show the errors... or absence thereof.
if it was the alternator, I would think Mbstar would pick up a fault . But it’s throwing this error on every single drive.
14.7 volts is getting a little high. You may want to consider replacing the voltage regulator on the alternator and see if the issue resolves. The red light could be being triggered by a transient overvoltage condition.
As for the buzzing by the battery box, if you have the orthopedic seats (and you should), there is an air pump behind the battery that provides pressure to the bladders in the seat. It will run periodically, especially if there is a leak in the lines/bladder.
Just out of curiosity; was the car at a salvage auction because it went for a "swim"? Just trying to start at the beginning because the voltage numbers you present seem OK to me.
14.7 volts is getting a little high. You may want to consider replacing the voltage regulator on the alternator and see if the issue resolves. The red light could be being triggered by a transient overvoltage condition.
As for the buzzing by the battery box, if you have the orthopedic seats (and you should), there is an air pump behind the battery that provides pressure to the bladders in the seat. It will run periodically, especially if there is a leak in the lines/bladder.
thanks for answering the humming sound question. Yes I do have the orthopedic seats and that makes sense.
could be the voltage regulator. I wish there was a way to know that for sure before undertaking an extensive repair .. is there a way to check?
Just out of curiosity; was the car at a salvage auction because it went for a "swim"? Just trying to start at the beginning because the voltage numbers you present seem OK to me.
good point. But no. No water damage. Car was at auction because of vadalism - someone stole the front bumper headlights and radio and slashed the wires for headlights and Distronic. I have sourced those parts and reconnected and saudered those wires carefully and shrink wrapped.
so yes, there was an electrical issue to begin with, but a visible one and has been carefully dealt with from what I can tell. The headlights and Distronic show no error and work fine. The only thing I haven’t figured out is the front parking sensors( again slashed wires) that doesn’t quite wanna work when I attach the replacement pigtail with new sensors. Could be a blown fuse from a previous short, but I am still working on finding out where the fuse for the front parktronic is - any help is appreciated.
The only thing I haven’t figured out is the front parking sensors( again slashed wires) that doesn’t quite wanna work when I attach the replacement pigtail with new sensors. Could be a blown fuse from a previous short, but I am still working on finding out where the fuse for the front parktronic is - any help is appreciated.
Yes, replacing the VR is a pita and may be more so on the twin turbo. Other than stored faults via the Star system, I don't know of any way to definitively diagnose an intermittent flakey regulator.
The transceivers for the parking sensors seem to be very prone to damage from short circuits in the sensor wiring - I have seen other posts about it. I don't think MB built in the proper short circuit protection for this system. You may be looking at a new module.
Yes, replacing the VR is a pita and may be more so on the twin turbo. Other than stored faults via the Star system, I don't know of any way to definitively diagnose an intermittent flakey regulator.
The transceivers for the parking sensors seem to be very prone to damage from short circuits in the sensor wiring - I have seen other posts about it. I don't think MB built in the proper short circuit protection for this system. You may be looking at a new module.
i have just let them be for the time being, but it seems i will have to go investigating. Interesting thing is that this error is new while i never got this in the last 3 months when i drove it around. Ah well. have to start somewhere. Any idea about where the Parktronic module is located. I did a google search and found a part number -
It seems really odd that the ECU is catching some anomaly that registers as an instrument panel annunciation, yet doesn't register in an OBD scan. But I agree that the place to start is with the alternator/regulator. See if you can find a shop that specializes in car electrical systems and that has a high-end alternator testing capability. This should allow the alternator activity to be analyzed without having to remove it from the vehicle. The bumperectomy shown in your photos would prompt me to do a thorough inspection of all the engine compartment wiring, especially around the alternator. The vandals were unlikely concerned with any collateral damage they caused.
It seems really odd that the ECU is catching some anomaly that registers as an instrument panel annunciation, yet doesn't register in an OBD scan. But I agree that the place to start is with the alternator/regulator. See if you can find a shop that specializes in car electrical systems and that has a high-end alternator testing capability. This should allow the alternator activity to be analyzed without having to remove it from the vehicle. The bumperectomy shown in your photos would prompt me to do a thorough inspection of all the engine compartment wiring, especially around the alternator. The vandals were unlikely concerned with any collateral damage they caused.
yes that’s what’s bothering me... why is this not showing up on Mbstar or obd.. I don’t feel like it’s smart to start taking the alternator apart , but at the same time, hard to ignore a red battery sign...
I don’t have a ton of good mechanic shops around, and they all bleed at the sight of a G. But I’ll see if someone can do some basic troubleshooting with the alternator. The alternator charges the car though, so I don’t think it’s bad. Maybe the voltage regulator.
yes that’s what’s bothering me... why is this not showing up on Mbstar or obd.. I don’t feel like it’s smart to start taking the alternator apart , but at the same time, hard to ignore a red battery sign...
I don’t have a ton of good mechanic shops around, and they all bleed at the sight of a G. But I’ll see if someone can do some basic troubleshooting with the alternator. The alternator charges the car though, so I don’t think it’s bad. Maybe the voltage regulator.
thanks
Chances are that the alternator is made by Bosch, who provides OE alternators to most of the Euro auto industry. Any shop that promotes itself as a Euro-specialist should be able to deal with it, and you might get lucky and find one that has a Bosch alternator tester. Have you checked the drive belt tension? A belt with marginal tension could be causing irregular charging behavior -- it could be slipping under a heavy charge load, but catching when the charge load is light. The OBD code for a low battery voltage is "P0562". However, the qualifying condition for this is a battery voltage less than 10 volts that lasts for 60 seconds, and the battery might not ever be reaching this. The instrument panel battery light might be triggering at a higher voltage and without a 60 second time prerequisite.
Chances are that the alternator is made by Bosch, who provides OE alternators to most of the Euro auto industry. Any shop that promotes itself as a Euro-specialist should be able to deal with it, and you might get lucky and find one that has a Bosch alternator tester. Have you checked the drive belt tension? A belt with marginal tension could be causing irregular charging behavior -- it could be slipping under a heavy charge load, but catching when the charge load is light. The OBD code for a low battery voltage is "P0562". However, the qualifying condition for this is a battery voltage less than 10 volts that lasts for 60 seconds, and the battery might not ever be reaching this. The instrument panel battery light might be triggering at a higher voltage and without a 60 second time prerequisite.
can’t find any problem with battery voltage. I’ve been driving it around and rechecking battery voltage and it stays at 12.6. Still keep getting that red error sign every time after I start a drive a few. Nothing wrong that a shop can find with alternator or voltage regulator. Could be the regulator brushes slipping when driving. Any way to find that short of just buying a new one and paying for replacement. Doesn’t look like something I could undertake as a DIY. Thoughts?
can’t find any problem with battery voltage. I’ve been driving it around and rechecking battery voltage and it stays at 12.6. Still keep getting that red error sign every time after I start a drive a few. Nothing wrong that a shop can find with alternator or voltage regulator. Could be the regulator brushes slipping when driving. Any way to find that short of just buying a new one and paying for replacement. Doesn’t look like something I could undertake as a DIY. Thoughts?
If you've been driving around with a voltage monitor active, and the battery icon is lighting with the voltage sitting at 12.6, the fault must be in the monitoring system. Is your display where this icon appears a color graphic display (like a smartphone) or is it an array of indicator lights behind a glass panel that is screened with fixed icons? If it's a graphic display, then the icon's appearance is originating at an ECU, and the ECU is getting bad information from the voltage sensor. Either a defective sensor or a bad connection somewhere in between -- maybe a loose wire or bad contact at a connector. This is really hard to T/S without a wiring diagram to know what to look for. Does the battery icon flicker on/off or is it stable when it lights? Does it stay on until you shut off the ignition, or does it come and go while you're driving?
If you've been driving around with a voltage monitor active, and the battery icon is lighting with the voltage sitting at 12.6, the fault must be in the monitoring system. Is your display where this icon appears a color graphic display (like a smartphone) or is it an array of indicator lights behind a glass panel that is screened with fixed icons? If it's a graphic display, then the icon's appearance is originating at an ECU, and the ECU is getting bad information from the voltage sensor. Either a defective sensor or a bad connection somewhere in between -- maybe a loose wire or bad contact at a connector. This is really hard to T/S without a wiring diagram to know what to look for. Does the battery icon flicker on/off or is it stable when it lights? Does it stay on until you shut off the ignition, or does it come and go while you're driving?
I have attached a picture of the red battery error. It comes up in the center of the instrument cluster. It usually comes on after a minute or two of actual driving. Interestingly if I just fire up the engine but don’t actually put the car in gear, and just let it idle standing - it doesn’t show up. It just shows up when I drive 30 sec or so. it’s a stable icon and doesn’t flicker. Goes away when I click the “ok” button. And then does not come back. I have drive. Around and then rechecked voltages and my battery holds charge. Also, I don’t get any other error messages in the dash. I checked with Mbstar Xentry as well- no errors whatsoever. Very frustrating- because it happens every time. More annoying than anything.
seems like a big task to undertake to switch ecu etc if it’s just a monitoring issue. That’s why I thought of asking the forum . Thanks
What is the voltage reading when you’re driving the car around and what is it when the red battery fault triggers in your cluster? I assume you have a way to monitor this in real time via a scantool.
What is the voltage reading when you’re driving the car around and what is it when the red battery fault triggers in your cluster? I assume you have a way to monitor this in real time via a scantool.
A convenient monitor device can be acquired on Amazon (or probably Walmart)
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