AFM issues '19 C7 GS
Thread Starter
Cruising
Joined: Dec 2020
Posts: 13
Likes: 2
AFM issues '19 C7 GS
My GS - with an A8 tranny - spends most of its time on the track. During a recent run at COTA, I had issues w/the car switching to V4 - in corners T1 and T12 (both "hairpin" turns) - despite using Track mode "race".
Is GM kidding? They're worried about MPG on a race track?? The switch is not seamless and eventually the CEL lit up - code showing issue w/the AFM pre-muffler valve - which messed up my afternoon.
My research indicates that the AFM is active in all modes with the A8 unless you use the paddles in manual mode. I have purchased the Range plug in and it seems to work well on the street - keeping the car in
V8 mode at all rpms and speeds. My concern is what will happen at track speeds. Is anyone using Range at the track?
Is GM kidding? They're worried about MPG on a race track?? The switch is not seamless and eventually the CEL lit up - code showing issue w/the AFM pre-muffler valve - which messed up my afternoon.
My research indicates that the AFM is active in all modes with the A8 unless you use the paddles in manual mode. I have purchased the Range plug in and it seems to work well on the street - keeping the car in
V8 mode at all rpms and speeds. My concern is what will happen at track speeds. Is anyone using Range at the track?
Drifting
Joined: Aug 2013
Posts: 1,502
Likes: 515
From: Hill Country Texas
If you were on the track long enough to get a CEL for the AFM I'd suggest that your probably a good candidate for HPTuners and a good tune for your 19 GS. Since you were driving at COTA, PatG is well worth the short drive down to Victoria.
Pro
Joined: Sep 2000
Posts: 678
Likes: 310
From: McKinney Texas
Common problem with cars with AFM actuators on track due to plastic parts being in the exhaust path.
They get too hot and the plastic sticks to the metal actuator wheel and they stick open or closed causing CELs and need to be replaced.
EDIT: forgot to add that its probably not AFM being "activated" in race mode, its the physical part failing and the causing the CEL.
They get too hot and the plastic sticks to the metal actuator wheel and they stick open or closed causing CELs and need to be replaced.
EDIT: forgot to add that its probably not AFM being "activated" in race mode, its the physical part failing and the causing the CEL.
Last edited by MCK_Z06; Jul 26, 2021 at 05:24 PM.
Pro
Joined: Sep 2000
Posts: 678
Likes: 310
From: McKinney Texas
Of course you still need to replace the current ones which are already damaged first.
Cheap....
AWE AFM Valve Simulators :: 2014-2019 C7 Corvette (phastekperformance.com)
Safety Car
Joined: Feb 2002
Posts: 3,725
Likes: 366
From: Montoursville Pa
If you don't want to tune but want to get rid of the problem for good when tracking the car you can install simulators and remove the valve from the exhaust path without throwing codes.
Of course you still need to replace the current ones which are already damaged first.
Cheap....
AWE AFM Valve Simulators :: 2014-2019 C7 Corvette (phastekperformance.com)
Of course you still need to replace the current ones which are already damaged first.
Cheap....
AWE AFM Valve Simulators :: 2014-2019 C7 Corvette (phastekperformance.com)
Drifting
Joined: Aug 2013
Posts: 1,502
Likes: 515
From: Hill Country Texas
Common problem with cars with AFM actuators on track due to plastic parts being in the exhaust path.
They get too hot and the plastic sticks to the metal actuator wheel and they stick open or closed causing CELs and need to be replaced.
EDIT: forgot to add that its probably not AFM being "activated" in race mode, its the physical part failing and the causing the CEL.
They get too hot and the plastic sticks to the metal actuator wheel and they stick open or closed causing CELs and need to be replaced.
EDIT: forgot to add that its probably not AFM being "activated" in race mode, its the physical part failing and the causing the CEL.
But I really don't want to remove my heads because then I would want to CNC port them for greater flows, and then of course if you're going to do that you're going to want to bump up the cam lift a tad bit to take advantage of those new flows. Just turns into a money pit!
Last edited by BigVette427; Jul 27, 2021 at 04:51 PM.
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