Remote lazy locking / venting. - Page 12

Simon · 23rd September 2009, 18:46

If you're wondering about the operation of the powerfold ECU Paul then this is how it works (and sorry if I'm re-posting something somone else has said or if I am repeating what you already know)

When you press the powerfold button it grounds a signal to the onboard chip on the switchpack PCB.

This signal is a momentary action (ie not latching) so it doesn't matter how long you hold the switch down for. When the onboard chip detects the current (ie grounded) then the chip does all the work. It sends out a timed current to the two mirrors via two wires (one earth, one live). I would suspect it does this by switching a relay. The clever part is it 'knows' which way it sent the current the previous time so on the next press of the button it reverses the current direction in the two wires that go to the mirrors.

The time the current is 'on' is timed by the onboard logic which also monitors the current drawn. If the current drawn exceeds a certain (pre-determined) limit it assumes the motors have stalled (impling the mirrors have reached the limit of their travel). Of course once the alloted time is also up the current is also switched off.

Sorry I can't help with which pins do what on the PCB

but that's generally how things work

I hope that is of some help.

If you were thinking of triggering the mirrors via the powerfold switch pack you only need to momenterially ground the powerfold button (or the equivilant track on the PCB).

Alternatively - the same logic is used for the Rover 45 powerfold ECU which is the same as the Freelander powerfold ECU. Now this is special because it is an independant ECU (as opposed to built-in to the window switch pack as per Rover 75). This means if you could obtain such an ECU you could wire it up to a remote-operated relay; ) The only (big) problem to this is that these particular ECU's are even rarer then the ellusive powerfold switchpacks

Raistlin · 23rd September 2009, 19:01

Thanks Simon

All input and ideas are appreciated

The situation as it stands is that I've identified switch pad SW20 on the top surface of the PCB as the powerfold switch contacts. Hopefully, Christopher (or anybody else who holds such arcane wisdom) is going to come up with which side of the pad is the circuit side and I'll find a location on the track to solder a wire to which won't impinge on the operation of the manual switch which is a "flexible membrane" type.

That can then pass out of the switchpack body and via a connector, go to one of the remote channel relays for momentary linking to earth when the appropriate transmitter button is pressed.

The other little problem is highlighted HERE. If no body has the definitive answer it'll have to be a trial and error check on the switchpack plugs to see where the permanent and ignition controlled supplies are and then a few experimental connections until I get it right (assuming my theory is correct).

Once that is sorted out I'll be ready to transfer from the present functional, if cumbersome, method.

23rd September 2009, 18:46	#111
Simon Banned - Join Date: Nov 2006 Location: - Posts: 10,318 Thanks: 0 Thanked 4 Times in 3 Posts	If you're wondering about the operation of the powerfold ECU Paul then this is how it works (and sorry if I'm re-posting something somone else has said or if I am repeating what you already know) When you press the powerfold button it grounds a signal to the onboard chip on the switchpack PCB. This signal is a momentary action (ie not latching) so it doesn't matter how long you hold the switch down for. When the onboard chip detects the current (ie grounded) then the chip does all the work. It sends out a timed current to the two mirrors via two wires (one earth, one live). I would suspect it does this by switching a relay. The clever part is it 'knows' which way it sent the current the previous time so on the next press of the button it reverses the current direction in the two wires that go to the mirrors. The time the current is 'on' is timed by the onboard logic which also monitors the current drawn. If the current drawn exceeds a certain (pre-determined) limit it assumes the motors have stalled (impling the mirrors have reached the limit of their travel). Of course once the alloted time is also up the current is also switched off. Sorry I can't help with which pins do what on the PCB but that's generally how things work I hope that is of some help. If you were thinking of triggering the mirrors via the powerfold switch pack you only need to momenterially ground the powerfold button (or the equivilant track on the PCB). Alternatively - the same logic is used for the Rover 45 powerfold ECU which is the same as the Freelander powerfold ECU. Now this is special because it is an independant ECU (as opposed to built-in to the window switch pack as per Rover 75). This means if you could obtain such an ECU you could wire it up to a remote-operated relay; ) The only (big) problem to this is that these particular ECU's are even rarer then the ellusive powerfold switchpacks

23rd September 2009, 19:01	#112
Raistlin Banned 75 CDT Connoisseur SE Auto Join Date: Nov 2006 Location: Wolverhampton Posts: 8,450 Thanks: 0 Thanked 3 Times in 3 Posts	Thanks Simon All input and ideas are appreciated The situation as it stands is that I've identified switch pad SW20 on the top surface of the PCB as the powerfold switch contacts. Hopefully, Christopher (or anybody else who holds such arcane wisdom) is going to come up with which side of the pad is the circuit side and I'll find a location on the track to solder a wire to which won't impinge on the operation of the manual switch which is a "flexible membrane" type. That can then pass out of the switchpack body and via a connector, go to one of the remote channel relays for momentary linking to earth when the appropriate transmitter button is pressed. The other little problem is highlighted HERE. If no body has the definitive answer it'll have to be a trial and error check on the switchpack plugs to see where the permanent and ignition controlled supplies are and then a few experimental connections until I get it right (assuming my theory is correct). Once that is sorted out I'll be ready to transfer from the present functional, if cumbersome, method.