This Technical Specification describes the pilot wire function designed as a control mechanism for the supply of electrical energy to electric vehicles, principally for the charging of the traction batteries of the vehicle. It concerns all charging systems that ensure the pilot function with a pilot wire circuit with PWM for mode 2, mode 3 and mode 4 charging as described in the IEC 61851 series. This document describes the functions and sequencing of events for this circuit based on the recommended typical implementation circuit parameters. The parameters indicated also ensure the interoperability of control pilot wire systems designed according to SAE J1772. This document is not applicable to vehicles using pilot functions that are not based on a PWM signal and a pilot wire. NOTE 1 In the context of this document the words “EV supply equipment” designate any one of the following: the AC EV supply equipment in mode 3, the in cable control box in mode 2 and/or the DC EV supply equipment in mode 4. NOTE 2 The control pilot wire is a supplementary conductor, in addition to the power lines linking the vehicle to EV supply equipment via the vehicle coupler.