Could anyone explain what relay 109 does and if the Superb 1.9tdi 2004 has one ?

My Superb is on it's way to the dealers with the latest of problems, the engine has no power at al land struggles to rev past 3k rpm, once it does it appears to get a bit of boost and pulls harder.

The dealer has already replaced the fuel pump relay as that is what the diagnostics said, when it came back from them the engine light had gone out but the engine was still bad :(

Also had the following wrong with it

no cruise

no steering wheel controls

no parking sensors

no head, tail or brake lights

occasional pre heater lights lit

I'm guessing it's all linked and it's going back to the dealer but I would like to ask here if anyone has any ideas as I keep reading about relay 109 !

thanks.

If the grey matter cells work correctly, I seem to recall relay 109 being the fuel pump relay that is a common VW group failure point on TDI's. Usual signs are car cutting out, jerking, loosing go then suddenly coming back to life.

I have had it myself on 3 VW group engines, and know of 3 others that it has happened to. Only 1 was a Skoda..my old Octy TDI 90.

I am not sure though if they use the same relay in the pd lumps.

109 relay is a main power relay, used to pack up loads on older cars but more modern updated versions dont give much trouble.