access to maserati technical docs

[granturismo]

has anyone got access? I want to identify the wiring for the exhaust valve solenoid on 2009 GT-S. Without diagram it is impossible to find out where is the relay for it.

 

[voicey]

I don't have a wiring diagram but I'm certain there wont be a relay for it. The solenoids are wired with two wires - one is a +ve that is switched with the ignition. The other is the earth that is switched by the ECU.

 

[Contigo]

I agree, as far as I understand no relay for the solenoid.

Whilst looking I found this for the Strad. Tell you about the exhaust valves in the different modes. The SPORT setting applies to the MC Shift too.

 

[Contigo]

 

[granturismo]

I don't have a wiring diagram but I'm certain there wont be a relay for it. The solenoids are wired with two wires - one is a +ve that is switched with the ignition. The other is the earth that is switched by the ECU.

are you sure about that as my working assumption was that its the 12v+ thats switchable and car only supplies 12v when it wants to close the valves? The wiring diagram for FD kit seem to suggest that as well.
It would be nice to have plug and play kit like there is one for Ferrari where you simply connect cable to IN plug to the controller and connect controller to the solenoid using stock OUT plug. If we could identify where is the 12v+ on the other end of the wiring then it could be intercepted at his point rather than under the car....

 

[Ebenezer]

"This provides enthusiasts with a distinctive resonance"

baked beans afficionados?

Eb

 

[voicey]

are you sure about that as my working assumption was that its the 12v+ thats switchable and car only supplies 12v when it wants to close the valves? The wiring diagram for FD kit seem to suggest that as well.
It would be nice to have plug and play kit like there is one for Ferrari where you simply connect cable to IN plug to the controller and connect controller to the solenoid using stock OUT plug. If we could identify where is the 12v+ on the other end of the wiring then it could be intercepted at his point rather than under the car....

I cannot be 100% sure as I've never tested a GT nor do I have access to the wiring diagram. I do however have a lot of experience with Ferrari and Porsche valved exhaust systems.

I have checked my notes and would like to revise my statement....

One side is connected to a steady 12V (switched by the ignition).

The other side is connected to the ECU - the ECU applies a voltage of between 0v and 5v which creates a voltage across the solenoid of between 7v and 12v. At 7V the valve is closed and at 12V fully open. The valves are not digitally operated and there is a transition phase between states to prevent them oscillating.

Also, aside from metering the voltage across the solenoid, the ECU also monitors the current draw. This allows it to check that the valve is operating correctly. On modern Ferraris, malfunctions are logged as errors P0475, P0477 and P0478 however they do not trigger a CEL.

In any case, it is fairly easy to verify with a multimeter....

 

[rs48635]

Great illustrations, thanks Phil.
Maybe I need similar silencer setup on my QP? The sport GT apprently has an H or X pipe and deleted pre-silencers. Will get underneath to check