Circuitry help - 2 stage relay or controller advice

got a puzzle to get round. We are looking at wiring up a motorcycle which uses canbus for the indicator tell tell on the speedo so we cannot completely rewire in a new system.

The problem specifics are that we are trying to replace the switch gear with nicer billet switch housings and momentary signal buttons (which do not carry a voltage but an earth signal when pressed). The main problem with this is that, when the signal wires are earthed, the ECU then puts the indicators on and sends a canbus signal to the speedo which then displays the indicator light.

Please see the schematic attached.

We think we need a ‘2 stage’ relay or controller, that will, when pressed the first time, activate the first function of bridging pins P4 and P6 to turn the left indicators on (or pins P4 and P6 for the right hand side), then when pressed again it bridges pins P4, P5 and P6 to cancel the indicators. The circuit then resets to function 1.

The bikes circuit is 12v and the bridge is a ground signal which goes to a load module.

Just wondering if any guru has an idea of what may work for this type of work around? I have thought about using an Arduino, but i cannot code!

Thanks in advance for any help.

Regards

James