Breakdown of how the multifunction relay functions
Pin 14 receives a switched live from the dash
This is wired to pin 12 internally, pin 12 goes to the ecu pin 13 and the factory immobliser box
ECU enters up powering up state, as a result pin 52 on the ecu goes to ground, completing the circuit on stage one of the ignition relay
The ground feed from the ecu goes to pin 10 on the ignition relay, stage one of the relay powers up.
This completes the circuit between pins 11 (fused live) and 1+9 of the relay. The ECU is now fully powered up, as is the charcoal canister valve.
Stage 2 is ECU controlled
A switched live is already present at pin 14, the ecu provides a negative feed during the prime function and cranking/engine running via the inertia switch to pin 7.
Provided the inertia switch is completing the circuit this completes the connection between the live pins on 8 and 15 to power the fuel pump, coil pack, speedo sender and injectors. (Pins 4,5,6,13 - your mileage may vary on which is which).
vts_ignition_system.txt · Last modified: 2016/08/18 20:27 (external edit)