AFM turned off by my dealer????

[MS3DALE]

General Motors Active Fuel Management engine control system has the ability, under certain light load driving conditions, to provide maximum fuel economy by deactivating 4 of the engines 8 cylinders. The engine will normally operate on 8 cylinders in V8 mode during starting, idling, and medium or heavy throttle conditions. When commanded ON, the engine control module (ECM) will direct the active fuel management system and deactivate cylinders 1 and 7 on the left bank and cylinders 4 and 6 on the right bank, forcing V4 mode.
To provide maximum fuel economy under light load driving conditions, the engine control module (ECM) will command the cylinder deactivation system ON to deactivate engine cylinders 1, 7, 6, and 4, switching to a V4 mode. The engine will operate on 8 cylinders, or V8 mode, during engine starting, engine idling, and medium to heavy throttle applications.
When cylinder deactivation is commanded, the ECM will determine what cylinder is firing and begin deactivation on the next closest deactivated cylinder in firing order sequence. For example, if cylinder number 1 is on its combustion event when cylinder deactivation is commanded ON, the next cylinder in the firing order sequence that can be deactivated is cylinder number 7. If cylinder number 5 is on its combustion event when cylinder deactivation is commanded ON, then the next cylinder in the firing order sequence that can be deactivated is cylinder number 4.
Cylinder deactivation is accomplished by not allowing the intake and exhaust valves to open on the selected cylinders by using special valve lifters. The deactivation lifters contain spring loaded locking pins that connect the internal pin housing of the lifter to the outer housing.
The pin housing contains the lifter plunger and pushrod seat which interfaces with the pushrod. The outer housing contacts the camshaft lobe through a roller. During V8 mode, when all cylinders are active, the locking pins are pushed outward by spring force, locking the pin housing and outer housing together causing the lifter to function as a normal lifter. When cylinder deactivation is commanded ON, the locking pins are pushed inward with engine oil pressure directed from the valve lifter oil manifold (VLOM) assembly solenoids. When the lifter pin housing is unlocked from the outer housing, the pin housing will remain stationary, while the outer housing will move with the profile of the camshaft lobe, which results in the valve remaining closed. One VLOM solenoid controls both the intake and exhaust valves for each deactivating cylinder. There are 2 distinct oil passages going to each cylinder deactivation lifter bore, one for the hydraulic lash-adjusting feature of the lifter, and one for controlling the locking pins used for cylinder deactivation.
Although both intake and exhaust valve lifters are controlled by the same solenoid in the VLOM, the intake and exhaust valves do not become deactivated at the same time. Cylinder deactivation is timed so that the cylinder is on an intake event. During an intake event, the intake cam lobe is pushing the valve lifter upwards to open the intake valve against the force of the valve spring. The force exerted by the valve spring is acting on the side of the lifter locking pins, preventing them from moving until the intake valve has closed. When the intake valve lifter reaches the base circle of the camshaft lobe, the valve spring force is reduced, allowing the locking pins to move, deactivating the intake valve. However, when cylinder deactivation is commanded ON, the exhaust valve for the deactivated cylinder is in the closed position, allowing the locking pins on the valve lifter to move immediately, and deactivate the exhaust valve.
By deactivating the exhaust valve first, this allows the capture of a burnt air/fuel charge, or exhaust gas charge, in the combustion chamber. The capture of exhaust gases in the combustion chamber will contribute to a reduction in oil consumption, noise and vibration levels, and exhaust emissions when operating in V4 mode cylinder deactivation mode.
During the transition from V8 to V4 mode, the fuel injectors will be turned OFF on the deactivated cylinders. To help prevent spark plug fouling, the ignition system secondary voltage or spark is still present across the spark plug electrodes on the deactivated cylinders. If all enabling conditions are met and maintained for cylinder deactivation operation, the ECM calibrations will limit cylinder deactivation to a cycle time of 10 minutes in V4 mode, then return to V8 mode for 1 minute.
Switching between V8 and V4 modes is accomplished in less than 250 milliseconds, making the transitions seamless and transparent to the vehicle operator. The 250 milliseconds includes the time for the ECM to sequence the transitions, the response time for the VLOM solenoids to energize, and the time for the valve lifters to deactivate, all within 2 revolutions of the engine crankshaft.

[MS3DALE]

Service Information




2011 Chevrolet Camaro | Camaro VIN F Service Manual | Document ID: 2218230
Cylinder Deactivation (Active Fuel Management) System Description
System Operation

General Motors Active Fuel Management engine control system has the ability, under certain light load driving conditions, to provide maximum fuel economy by deactivating 4 of the engines 8 cylinders. The engine will normally operate on 8 cylinders in V8 mode during starting, idling, and medium or heavy throttle conditions. When commanded ON, the engine control module (ECM) will direct the active fuel management system and deactivate cylinders 1 and 7 on the left bank and cylinders 4 and 6 on the right bank, forcing V4 mode. Refer to Lubrication Description and Cylinder Deactivation (Active Fuel Management) System Description.
Valve Lifter Oil Manifold Assembly




The valve lifter oil manifold assembly (1) is bolted to the top of the engine block beneath the intake manifold assembly. The oil manifold consists of 4 electrically operated and normally-closed solenoids (2). Each solenoid directs the flow of pressurized engine oil to the active fuel management intake and exhaust valve lifters (5). The active fuel management oil pressure relief valve (6), located in the oil pan, regulates engine oil pressure to the lubrication system and the oil manifold.
When enabling conditions are met for active fuel management operation, the ECM will ground each solenoid control circuit in firing order sequence, allowing current to flow through the solenoid windings. With the windings energized, the solenoid valves open and direct pressurized engine oil through the valve lifter oil manifold into 8 vertical passages in the engine block lifter valley. The 8 vertical passages, 2 per cylinder, direct pressurized oil to the valve lifter bores of the cylinders to be deactivated. When vehicle operating conditions require a return to V8 mode, the ECM will turn OFF the ground circuit for the solenoids, allowing the solenoid valves to close. When the solenoid valves are closed, remaining oil pressure is exhausted through the bleed passages of the valve lifter oil manifold into the engine block lifter valley. The housing of the oil manifold incorporates several oil bleed passages that continually purge trapped air from the manifold and engine block.
To help control contamination within the active fuel management hydraulic system, a small replaceable oil filter (4) is located in the valve lifter oil manifold oil inlet passage. The oil pressure sensor (3) monitors engine oil pressure and provides information to the ECM.
Active Fuel Management Valve Lifters




When operating in V8 mode, the active fuel management valve lifters function similar to the non-active fuel management valve lifters. The active fuel management oil manifold solenoids are in the closed position, with no pressurized oil directed to the valve lifters. The pushrod (1) travels upward and downward to actuate the rocker arm and valve. The spring loaded locking pins (5) of the lifter are extended outward and mechanically lock the pin housing (4) to the outer body of the valve lifter (3).
When the active fuel management system is commanded ON, the ECM will direct the solenoids of the oil manifold to open and direct pressurized oil to the valve lifters. Oil travels through the valve lifter oil manifold and engine block oil galleries and enters the inlet port (6) of the valve lifter.
When operating in V4 mode, pressurized oil forces the locking pins (11) inward. The pushrod (7) remains in a constant position and does not travel upward and downward. The outer body of the lifter (9) moves upward and downward independently from the pin housing (10). The valve lifter spring (8) retains tension on the valve train components to eliminate valve train noise.
When the active fuel management system is commanded OFF, the ECM directs the solenoids of the oil manifold to close, stopping the flow of pressurized oil to the valve lifters. The oil pressure within the lifter will decrease and the locking pins will move outward to mechanically lock the pin housing and outer body.
Engine Block




The active fuel management engine block incorporates additional features to support active fuel management system operation. Engine oil pressure is routed to the valve lifter oil manifold assembly from an oil gallery (2) in the rear of the cylinder block. Cylinders 1, 4, 6, and 7 each have 2 vertical, cast-in-block oil passages (1). The vertical oil passages permit oil flow from the manifold assembly to the valve lifter bores.

[Kman 2011 ss]

making the transitions seamless and transparent to the vehicle operator.

[MS3DALE]

I can't comment on the Camaro's,as mines an LS3 without it,but on my '07 6.0 VMAX Silverado it is very seamless,Until I installed my CORSA I had to look at the DIC to see if I was V4 or V8 mode.

[kaler]

I have my afm tuned out so I have know idea if this works or not, but worth a try.

1. Select M on the shift selector.
2. Tap up to display 6th
3. Tap down to display 5th
4. Tap back up to 6th

At this point AFM will be deactivated and won't reactivate until the shift lever is moved back to the D position.

[Rcfiddy1]

Originally Posted by kaler

I have my afm tuned out so I have know idea if this works or not, but worth a try.

1. Select M on the shift selector.
2. Tap up to display 6th
3. Tap down to display 5th
4. Tap back up to 6th

At this point AFM will be deactivated and won't reactivate until the shift lever is moved back to the D position.

No, it will still go into AFM. At least on my 2010 it did. I tested this many times and when I put in my Long tube headers I really noticed it. Now its history and I still get 22-24 mpg with my ECS tune and no more AFM gurgle and the so called unnoticeable transition. It was more like a 1.5 sec lag then jerk.

[Switchback700]

Originally Posted by Rcfiddy1

No, it will still go into AFM. At least on my 2010 it did. I tested this many times and when I put in my Long tube headers I really noticed it. Now its history and I still get 22-24 mpg with my ECS tune and no more AFM gurgle and the so called unnoticeable transition. It was more like a 1.5 sec lag then jerk.

It worked for me... on my 4 hour drive to the cottage this method was a brain saver after putting my axle back on. AFM would not kick in when going to manual mode. A manual paddle shift to 5th and back to 6th was all I had to do to keep AFM off for the whole drive.

[KARBON]

Once in the manual mode and the procedure is done can you go into "S" mode and afm still be off or do you have to paddle shift and be in manuel mode ?

[Switchback700]

Originally Posted by KARBON

Once in the manual mode and the procedure is done can you go into "S" mode and afm still be off or do you have to paddle shift and be in manuel mode ?

You need to stay in manual mode...... if you hold the right paddle for 2 seconds and it goes back to S mode the AFM will come back on. You'll be highway cruising in 6th gear manual. The only negative is if you go to pass someone and forget you are in manual 6th the trans will not downshift automatically, you have to use the paddles to downshift.

[myold88]

Originally Posted by fastfreddie

I'm taking the car in for service tomorrow and was thinking of asking my dealer if he would turn off the AFM. It drives me crazy at cruising speeds.

Has anyone had their dealer do it? And, did they say that it would void your warranty?

FF

I couldn't hear the AFM on my 2010 L99 SS with the stock exhaust- Never ! Maybe you should have your dealer check your computer &/or exhaust.
Now that I have Solo J-pipe axle backs it's still undetectable.
I guess the AFM droan varies from car to car.

[first one]

Originally Posted by MS3DALE

I can't comment on the Camaro's,as mines an LS3 without it,but on my '07 6.0 VMAX Silverado it is very seamless,Until I installed my CORSA I had to look at the DIC to see if I was V4 or V8 mode.

Does the DIC in the camaro show if you're in 4 cylinder mode or 8?

[Rock-It Man]

My 2010 will switch to 4 cylinders in manual mode when cruising on the highway.

In M, it will stay on 8 cylinders when cruising at lower speeds, below 40 mph or so, whereas, in D, it will switch to 4 cylinders at rediculously low speeds, as soon as you stop accelerating.

Is it seamless? I can hear the switch, but can't really feel it.

[Switchback700]

Originally Posted by Rock-It Man

My 2010 will switch to 4 cylinders in manual mode when cruising on the highway.

If you just leave it in manual without paddle shifting it will utilize AFM, once you paddle shift down to 5th gear and back to 6th AFM stays off.

[aet08]

turn that shit off and get a real tune, you car will perform so much better, tune the transmission also. night and day difference.