I Fault Code: DF025, Pre Heating Unit Diagnostic Connection open circuit.

Heater Plugs removed and checked.

I have found there is no 12v supply to Heater Plugs from cold. On this vehicle, is this correct or not?

I have removed Pre-Heating Unit from Passenger Wheel Arch, and checked Wiring as follows:

4 Wires, to Heater Plugs
1 Large Red, permanent live
1 Large White, Earth
and there are 2 smaller wires, 1 Brown, Ignition on 4v and other small wire, 12v.

Is this correct or not?

Can anyone advise on how this cold start system works, if that is the problem?

Not sure if the Pre-Heater Unit is the fault at this stage, as Renault dealer has never supplied or had one requested by trade.

Am reluctant to fit one on, as have read on the internet, that people have tried this and found it not to be the fault.

Any steer appreciated.

Cheers Ian