Engine speed
Engine speed |
Information on engine speed is necessary to enable:
• |
the control module, together with
information on the positions of the main throttle butterfly and the TCS throtlte butterfly, to
calculate engine torque
|
• |
the control module, together with speed signals from the wheels, to calculate the
appropriate gear.
The signal is a square wave measuring about 40 Hz at idling speed and about 125 Hz at 2500 rpm. In the event of an incorrect signal or if there is no continuity or a short in the circuit, then diagnostic trouble codes are generated, the TCS OFF lamp lights up and the system is rendered inoperative. |