ECM pods that could trigger SA-2 missile self-destruction

[yahya]

I have a technical question. Was there any ECM pod used in Nam that could trigger SA-2 missile's self-destruction after launch by sending specially modulated fuze activation signals? Reportedly, the SA-2 ground operators could trigger SA-2 missile's self destruction to cause damage by fragmentation when ECM jamming prevented precise guidance to an airborne target. Could this have been exploited by US side? Did this require powerful ECM transmitters or just knowing the right frequency and guidance signal's structure?

Peter Davies wrote in F-105 Wild Weasel Vs. SA-2 Guideline SAM. Vietnam 1965-73:

The SA-2’s uplink, downlink and radar proximity fuzing codes were not obtained until February 13, 1966, when a Blue Spring/United Effort Ryan Model 147E drone from Bien Hoa AB was shot down by two SA-2s near Hanoi seconds after re-transmitting the relevant data to a USAF RB-47H. It was, in the Assistant Secretary to the Air Force’s opinion, “the most significant contribution to electronic reconnaissance in the past 20 years”.

How were these codes exploited after that? Were the transmissions to and from the FR-15Yu missile's command link worked out to detonate the SA-2 before it could do any damage?