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I should. But it's kinda protected where it is, as you can see from my pristine engine bay! Seriously, I don't think it will get dirty, but if I knew that parts to get, I would cap them off. I don't think I can get in there with a heat gun or torch and some shrink tubing.
True true, might not be a problem just leaving it exposed but if you really want to, maybe electrical tape will be the alternative to shrink tubbing?
I was able to on the C350, just not the SL. I guess it really depends on how much room you have in the engine bay. The connector is toward the bottom of the alternator, but facing the wheel well, away from the engine. If you have room to reach, maybe you can get it from the top. I just don't know how much room the turbo takes up on that side. I could reach and feel it from the top; I just couldn't get a screwdriver down there to pop that little gray latching clip and my thumbnail wasn't strong enough.
Thanks for the pointers, yikes another of those locking pin plugs, this should be fun : )
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by W205C43PFL
Thank you, so does the plug just come off when you pull and no locking tab like the CPS?
Yes, there is a locking tab. That's what I meant.
Going at it from the bottom, I used a stubby flat tip screwdriver to pop the locking tab up. It still required some wriggling and pushing the connector (not the tab) in a little to pull it off. I think I just needed to break it loose a bit.
Going at it from the bottom, I used a stubby flat tip screwdriver to pop the locking tab up. It still required some wriggling and pushing the connector (not the tab) in a little to pull it off. I think I just needed to break it loose a bit.
OK, just got done unplugging the SL400 alternator (it got to a balmy 27°F today). I will be going out in a little while to see how she drives. I will report back.
Did you end up driving the SL400? How was the experience with it unplugged?
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by Manny_c450
Did you end up driving the SL400? How was the experience with it unplugged?
Yes, I did. Seemed pretty much normal, though shifting was a little smoother and it seemed a little more responsive in higher gears without downshifting. That's noticeable because I tried both Sport and Agility modes, and Agility (a.k.a., Sport+) usually downshifts if I even think about it. This was a couple of short drives, maybe 25 miles total. I will need to try in E mode and see if I notice a difference.
That is curious. I wonder if looking at a wiring diagram would help figure it out. PM me (or post here) your VIN and I will try to find it in the WIS.
Lets see what's special abou his alternator schematic...
> THINKING CAP :
wait a minute... we always find plan B's for our friends...
Unplug BATT LIN sensor (aka. Hyundai Batt sensor) should disable Bosch ECU variable voltage feature.
It also will disables IC showing batt sensor... so you'll want to use a 12V plug-in phone charger that shows voltage or your OBD-II scanner to display SAM Voltage live data!
Last edited by CaliBenzDriver; Jan 15, 2025 at 09:01 PM.
Yes, I did. Seemed pretty much normal, though shifting was a little smoother and it seemed a little more responsive in higher gears without downshifting. That's noticeable because I tried both Sport and Agility modes, and Agility (a.k.a., Sport+) usually downshifts if I even think about it. This was a couple of short drives, maybe 25 miles total. I will need to try in E mode and see if I notice a difference.
cool, I guess you will leave the ALT IN left unplugged on both cars and won't be reconnecting them ever..
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by JettaRed
That is curious. I wonder if looking at a wiring diagram would help figure it out. PM me (or post here) your VIN and I will try to find it in the WIS.
@Jaybird123 here is the wiring diagram for an E63 (212.277). It shows a single wire going from the alternator to the ECU. With your specific car model, I could make sure I am looking at the correct diagram.
EDIT: Also note that the single LIN wire is BLUE (BU). The connector in @Jaybird123 photo shows an orange and white wires. Maybe that is a picture of the wrong connector. I can't find two wires like that in any of the schematics.
Last edited by JettaRed; Jan 15, 2025 at 09:16 PM.
Lets see what's special abou his alternator schematic...
> THINKING CAP :
wait a minute... we always find plan B's for our friends...
Unplug BATT LIN sensor (aka. Hyundai Batt sensor) should disable Bosch ECU variable voltage feature.
It also will disables IC showing batt sensor... so you'll want to use a phone charger that shows voltage or your OBSIO Scanner to display SAM Voltage live data!
this could be a quick PLAN-B to get stable voltage... BATT Sensor unplugged
Somebody with ALT-LIN still plugged in can try and confirm 5mn quicky
ECU will still talk to ALT-LIN but should no longer play the [12.6V to 14.9V] chaos game.
The "drained by driving" below 12.0V bug may till be active because ECU can still mis-control ALT-LIN while it is plugged in.
I can not test this scenario with my ALT-LIN being disconnected...
Last edited by CaliBenzDriver; Jan 15, 2025 at 08:35 PM.
Lets see what's special abou his alternator schematic...
> THINKING CAP :
wait a minute... we always find plan B's for our friends...
Unplug BATT LIN sensor (aka. Hyundai Batt sensor) should disable Bosch ECU variable voltage feature.
It also will disables IC showing batt sensor... so you'll want to use a phone charger that shows voltage or your OBSIO Scanner to display SAM Voltage live data!
Somebody with ALT-LIN still plugged in can try and confirm 5mn quicky
ECU will still talk to ALT-LIN but should no longer play the 12.6V to 14.9V games.
The "drained by driving" below 12.0V bug may till be active because ECU can control ALT-LIN while plugged in.
Interesting, life will be way easier if that can achieve the same thing, as I remember forum members been unplugging that just to disable auto start/stop, no one reported how it changed the vehicle's drive though like transmission shift logic or acceleration. https://mbworld.org/forums/c-class-w...tart-stop.html
@Jaybird123 here is the wiring diagram for an E63 (212.277). It shows a single wire going from the alternator to the ECU. With your specific car model, I could make sure I am looking at the correct diagram.
Here is the way to cut wire inside ECU connector: Con-M Pin-45 blu wire: snap !
If you solder a toggle switch you can enable/disable ALT-LIN to remove related ECU Fault on demand.
Last edited by CaliBenzDriver; Jan 15, 2025 at 08:51 PM.
The main change they reported unplugging that is higher idle. So very interesting if this does the same thing as unplugging the LIN.
Call it ALT-LIN and BATT-LIN as they are both LIN Buses single wire.
Give it a shot you'll know quickly what voltage regulation is like with BATT-LIN out.
Try heavy electric loads combination (Rear Defrost + HL + Seat Heaters + wipers + AC Fan + ...)
I favor ALT-LIN to disable standard yoyo that lets engine/tranny adapt to stable timings.
Call it ALT-LIN and BATT-LIN as they are both LIN Buses single wire.
Give it a shot you'll know quickly what voltage regulation is like with BATT-LIN out.
Try heavy electric loads combination (Rear Defrost + HL + Seat Heaters + wipers + AC Fan + ...)
me too!
you can test one method then the other to accommodate your constraints.
Besides BATT-LIN will be a different fault in a different module: the Rear-SAM.
> Combination offer flexible options :
SMOG Test : ECU fault free while ALT-LIN plugged back and BATT-LIN pulled temporarily (once tested to be suitable).
Last edited by CaliBenzDriver; Jan 15, 2025 at 09:27 PM.
me too!
you can test one method then the other to accommodate freezing weather constraints.
Besides BATT-LIN will be a different fault in a different module: the Rear-SAM.
Options offer good flexibility....
SMOG Test : ECU fault free while ALT-LIN plugged back and BATT-LIN pulled temporarily.
True, good to have options. Sticking with ALT-LIN problem is my back will complain at me I will see what can I do or if I can figure out how to do it from the top ill post it and share but if not I will need to just go from the bottom.
problem is my back will complain at me I will see what can I do or if I can figure out how to do it from the top ill post it and share but if not I will need to just go from the bottom.
