Porsche Macan Forum banner
1421 - 1440 of 1483 Posts

·
Registered
2017 GTS, Cobb OTS, AMS filters
Joined
·
41 Posts

·
Registered
Joined
·
48 Posts
Just wanted to share a quick story that may help some folks thinking about a Cobb tune but afraid of the install. I installed a Cobb tune without a battery charger about 6 months ago. I went to restore to factory settings and again, didn’t use a battery charger. When the install got to 26% my car turned off (I assume because the battery was low but the voltage reading was near 12). It was completely bricked - every error code imaginable. Wouldn’t start. A total mess. So I tried the Cobb tune recovery. Car kept turning off at 19%. Disaster. I’m panicking. All that bad stuff. So I go to autozone and get a trickle charger. Plug it all in and try the recovery again. Again, car dies at 19%. Finally, I leave the car hooked up to the trickle charger for 10 minutes or so and try again. Eureka. Cobb recovers the ECU and all is well. Point being - the whole thing is pretty much idiot proof. If that didn’t destroy the ECU, I’m not sure what would. While it was a pretty scary experience, it gave me a lot of confidence in the Cobb Accessport and software!
 

·
Premium Member
2017 Black Turbo PSE|PASM|SC|ACC
Joined
·
179 Posts
Glad to see you have a happy ending. I wonder what your saved error codes reflect if anything.
 

·
Registered
Joined
·
2,785 Posts
Just wanted to share a quick story that may help some folks thinking about a Cobb tune but afraid of the install. I installed a Cobb tune without a battery charger about 6 months ago. I went to restore to factory settings and again, didn’t use a battery charger. When the install got to 26% my car turned off (I assume because the battery was low but the voltage reading was near 12). It was completely bricked - every error code imaginable. Wouldn’t start. A total mess. So I tried the Cobb tune recovery. Car kept turning off at 19%. Disaster. I’m panicking. All that bad stuff. So I go to autozone and get a trickle charger. Plug it all in and try the recovery again. Again, car dies at 19%. Finally, I leave the car hooked up to the trickle charger for 10 minutes or so and try again. Eureka. Cobb recovers the ECU and all is well. Point being - the whole thing is pretty much idiot proof. If that didn’t destroy the ECU, I’m not sure what would. While it was a pretty scary experience, it gave me a lot of confidence in the Cobb Accessport and software!
You were very lucky!!! When that happens, you're not always so. The folks at Cobb wouldn't want anyone to do what you did, as I'm sure you wouldn't make the same mistake again, either. There's a reason the warning is written on the install booklet. FWIW, the Porsche Techs always hook up the battery charger before they do an ECU update.
 

·
Registered
Joined
·
329 Posts
We had a tech killing the PDK control unit at the shop because someone kicked the battery charger plug and the voltage on the car dropped while doing a PDK reflash.
This is why I get extremely angry when some "I know everything in life about everything" talk about their pirate adventures fixing their porsche in their driveway, and not happy with that they encourage other people to do the same. If you know anything about newer cars like the Macan you know that they MUST have a proper charger hooked up at all times when working on any electronics, Porsche request 40 amp or keeping the battery level up to 14V, this is why the PIWIS will give you a low battery alert if that condition is not meet.
 

·
Registered
Joined
·
48 Posts
Haha definitely learned my lesson about the charger. Honestly, I was convinced by many posts here/online about people doing the flash without chargers -- seemed as though those using a charger were in the minority. I definitely won't be doing it without the charger moving forward!
 

·
Premium Member
Joined
·
3,224 Posts

·
Registered
Joined
·
48 Posts
Just to add - with a 20amp charger, voltage drops from 13 to 11 during the tune, so that’s obviously why they recommend a charger. I am sure the car turns off around 10, which is the issue with not using a charger. I used this one: Clore Automotive PL2320 20-Amp Fully-Automatic Smart Charger, 6V and 12V Battery Charger, Battery Maintainer, and Battery Desulfator with Temperature Compensation Amazon.com: Clore Automotive PL2320 20-Amp Fully-Automatic Smart Charger, 6V and 12V Battery Charger, Battery Maintainer, and Battery Desulfator with Temperature Compensation: Automotive
 

·
Registered
Joined
·
12 Posts
Does anyone else have a recommendation of a specific 20 amp charger?

I picked up a COBB and need to grab one soon.

Interesting- I just spoke with COBB and they said 10-15A manual (not automatic) was what we need. I have a 10A...
 

·
Registered
Joined
·
105 Posts
I have flashed Cobb tunes on dozens of porsches, Nissan's and Subaru's over the past 8 years and not once has a charger ever been needed. You are being over cautious. Your battery would have to be very depleted for an ECU flash to fail due to low voltage.
 

·
Premium Member
Joined
·
3,224 Posts
I have flashed Cobb tunes on dozens of porsches, Nissan's and Subaru's over the past 8 years and not once has a charger ever been needed. You are being over cautious. Your battery would have to be very depleted for an ECU flash to fail due to low voltage.
Cobb says use a charger. It is their deal and they must have a disaster that occurred to make this requirement prominent in their installation booklet. I know I wouldn't want to go hat in hand to the dealer and ask them for a new ECU.
 

·
Registered
Joined
·
329 Posts
I have flashed Cobb tunes on dozens of porsches, Nissan's and Subaru's over the past 8 years and not once has a charger ever been needed. You are being over cautious. Your battery would have to be very depleted for an ECU flash to fail due to low voltage.
So basically because you got lucky everybody should screw what Cobb says and flash their cars while waiting on the Starbucks drive thru?
I don't think so, Porsche recommends at least 14V to carry out any diagnostic, you don't have 14V on your terminal 15 unless you connect a charger, why taking unnecessary risks when doing it right is so easy?
 

·
Registered
2018 Porsche Macan GTS
Joined
·
808 Posts
Does anyone else have a recommendation of a specific 20 amp charger?

I picked up a COBB and need to grab one soon.

Interesting- I just spoke with COBB and they said 10-15A manual (not automatic) was what we need. I have a 10A...
This is the one I use. It was inexpensive and has a manual mode. https://www.amazon.com/dp/B007ESQW08/ref=cm_sw_em_r_mt_dp_ZPeYFbGCFD1P2?_encoding=UTF8&psc=1

This is the one the guys at Cobb use Microprocessor-Controlled Battery Charger/Maintainer

other than the price they are almost identical.
 

·
Registered
Joined
·
393 Posts
I have flashed Cobb tunes on dozens of porsches, Nissan's and Subaru's over the past 8 years and not once has a charger ever been needed. You are being over cautious. Your battery would have to be very depleted for an ECU flash to fail due to low voltage.
Are you sure you knew the condition of the battery in each car before taking a risk like this? Granted chances of a problem are low, but it’s not unheard of, and the results could be relatively catastrophic.
 
1421 - 1440 of 1483 Posts
Top