DS3 glow plug relay location?

[hairgoneJohn]

Hi

2012 1.6Hdi

I'm getting fault codes P1403 & P1404.

P1403 : Additional heating 1 command
Characterisation : open circuit or short circuit to positive or short circuit to earth
Status : intermittent fault.
Location : local
Variables associated with the fault
engine coolant temperature : 037 °C
Engine speed : 0000 Rpm
Pressure in the rail : 0000 bar
turbocharging pressure : 1020 mBar
vehicle speed : 000 kph
Inlet air temperature : 035 °C
atmospheric pressure : 1010 mBar
battery voltage : 12.28 V
4 of 10 06/11/2025 12:59
Vehicle mileage when the fault appeared : 0 km
exterior temperature : 004 °C
Control of the additional heating relay 1 : inactive
Control of the additional heating relay 2 : inactive
Pedal position consolidated : 000 %
Status of engine : cut off stalled

P1404 : Additional heating 2 command
Characterisation : open circuit or short circuit to positive or short circuit to earth
Status : intermittent fault.
Location : local
Variables associated with the fault
engine coolant temperature : 037 °C
Engine speed : 0000 Rpm
Pressure in the rail : 0000 bar
turbocharging pressure : 1020 mBar
vehicle speed : 000 kph
Inlet air temperature : 035 °C
atmospheric pressure : 1010 mBar
battery voltage : 12.28 V
Vehicle mileage when the fault appeared : 0 km
exterior temperature : 004 °C
Control of the additional heating relay 1 : inactive
Control of the additional heating relay 2 : inactive
Pedal position consolidated : 000 %
Status of engine : cut off stalled

Does "Additional heating 1 command" refer to glow plug on cyl 1?

I thought that a good place to start would be to check the resistance from the glow plug relay to earth for each plug to see if any wires/ plugs are defective.

I can't find the relay though !

Anyone know the location please?

I've found a relay underneath the air intake but I'm not convinced it is the GP relay. It has two plugs. There is also a relay sitting horizontally on the left wing? Does anyone know the pinout please for which pins go to each plug?

[mickthemaverick]

This may be useful when you do find the relay on your car.

[myglaren]

My son had a 306 and had a similar problem. The relay was very easy to find and if I remember correctly, I just pulled it out of the socket and pushed it back in a few times to clean the contacts. Worked fine after that until he sold it.

[hairgoneJohn]

Thanks. I've seen that video.

However my DS3 is different as shown in the photos.

I would like confirmation that I have the correct box and also the pinout. I can't find any DS3 wiring diagram online.
Plus of course, do P1403 and P1404 refer to glow plugs?