03 · Wiring
Crank, cam, flex & VSS
One VR crank pair, one dedicated Hall input, two multi-use Hall / flex / temp pins. No RPM on A4 means the engine will not fuel or spark.
VR crank
Most OEM crank sensors on 36-1, 60-2 and 12-1 wheels are VR. VR+ to A4, VR− to A3, twisted pair, shield earthed at the ECU analog ground only. If you see RPM while cranking but the engine will not sync, swap A4 and A3 before touching the trigger-type setting.
Hall crank
Three-wire Hall: 5 V or 12 V supply, signal to A4, ground to sensor ground. Leave A3 unconnected.
Cam, VSS, flex
F4 is the primary Hall input (cam by default). G3 and G1 can be Hall, flex-fuel frequency, VSS, or thermistors. Sequential 4-cylinder COP needs a cam. 6- and 8-cylinder batch / wasted spark run on crank only — F4 is then free for wheel speed.