Speed Signal Output

OUTPUTS
The ignition ECU generates the speed signal to the P.1. ECU. The frequency of the signal is 6 pulses per engine revolution. Check the output using an oscilloscope. Connect the positive to ECU pin 24 or the underbonnet connection between the ignition harness and the main P.1. harness (screened lead). Connect the negative to the chassis or engine earth.

The ignition ECU also triggers the signal to the ignition amplifier units.




Key to Fig 1
A = 400 micro seconds
B = Approximately 1 volt less than battery voltage
C = Zero volts
D = 1 engine revolution