Heater Plugs on a 407 Diesel 1.6?

Connecting diagnostics to the car gives reading "pre-post heating relay circuit, Plugs never supplied".

Does this mean there are no plugs supplied with the car, or no power to the plugs?

Where are they, all I can see is the injectors, on my 406 they were clearly visible, near to the injectors.

a.poole at warwick dot ac dot uk