E63s ECU Limp mode after tune
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Joined: Mar 2020
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2014 E63s AMG
E63s ECU Limp mode after tune
Hey guys so I got a tune and I'm having an issue where only when I'm pulling hard I'll go into limp mode "pre-safe functions limited" error on my dash but this is only when I'm accelerating hard. Regular driving it's fine... it's a stage 2 tune 740hp but it's a reliable tuner that I've seen do other cars from Lambos and amg gts so I dont think the tune is the issue in particular but if not what could it be?
Senior Member
Joined: Jul 2018
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E63s
Hey guys so I got a tune and I'm having an issue where only when I'm pulling hard I'll go into limp mode "pre-safe functions limited" error on my dash but this is only when I'm accelerating hard. Regular driving it's fine... it's a stage 2 tune 740hp but it's a reliable tuner that I've seen do other cars from Lambos and amg gts so I dont think the tune is the issue in particular but if not what could it be?
down pipes?
stock plugs? Fresh plugs? Gap?
Is it misfiring? Any cel?
Member
Joined: Nov 2019
Posts: 145
Likes: 38
2014 E63 AMG
Hey guys so I got a tune and I'm having an issue where only when I'm pulling hard I'll go into limp mode "pre-safe functions limited" error on my dash but this is only when I'm accelerating hard. Regular driving it's fine... it's a stage 2 tune 740hp but it's a reliable tuner that I've seen do other cars from Lambos and amg gts so I dont think the tune is the issue in particular but if not what could it be?
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Junior Member
Joined: Mar 2020
Posts: 42
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2014 E63s AMG
Hey guys so it looks like it was the tune as I went back and had a backup tune installed and the car is no longer going into limp mode, the tuner did say that his tune engineer in germany said the tune should of worked. What we are thinking is that it was too aggressive for not having downpipes. Reason being it would only go into limp mode when gradually accelerating hard for example trying to overtake another car would cause the car to downshift then the increase in speed would get halted by the limp mode. But let's say I'm at a standstill and I floor it the car will accelerate hard but no limp mode (2/3 times) which is odd, or if I'm just cruising it's fine as well, so we're assuming it had something to do with backpressure in the cats. I will say though that the code was something a long the lines of "ecu rejecting power requested by tcu" I cant remember exactly but I got a tcu update and it still happened so the backup tune which to me feels a bit less aggressive hasn't thrown that code.
Thanks for the advice though guys, I think I'll get downpipes and try that tune again sometime in the future.
Thanks for the advice though guys, I think I'll get downpipes and try that tune again sometime in the future.
Last edited by Mikesoja; May 5, 2020 at 12:27 PM.
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Joined: Feb 2018
Posts: 604
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From: Houston Tx
2014 AMG E63S and 2020 AMG GTC
Hey guys so it looks like it was the tune as I went back and had a backup tune installed and the car is no longer going into limp mode, the tuner did say that his tune engineer in germany said the tune should of worked. What we are thinking is that it was too aggressive for not having downpipes. Reason being it would only go into limp mode when gradually accelerating hard for example trying to overtake another car would cause the car to downshift then the increase in speed would get halted by the limp mode. But let's say I'm at a standstill and I floor it the car will accelerate hard but no limp mode (2/3 times) which is odd, or if I'm just cruising it's fine as well, so we're assuming it had something to do with backpressure in the cats. I will say though that the code was something a long the lines of "ecu rejecting power requested by tcu" I cant remember exactly but I got a tcu update and it still happened so the backup tune which to me feels a bit less aggressive hasn't thrown that code.
Thanks for the advice though guys, I think I'll get downpipes and try that tune again sometime in the future.
Thanks for the advice though guys, I think I'll get downpipes and try that tune again sometime in the future.
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Senior Member
Joined: Feb 2020
Posts: 352
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From: Northern Va
2014 E63s
I'd highly recommend using a tune from a reputable tuner, and avoid shops who use some mystery tuner in a foreign country, even if it is Germany. If they are not doing the actual tuning and won't tell you whose tune is being loaded into your car, that sounds sketchy to me. You're putting a lot at risk going that route,
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