Hi, That's just a header tank for levels, not the actual holder for the coolant. If the heater is cold then you have an air lock. Park facing uphill with van warm/hot and carefully (best use a cloth to cover the metal radiator cap) undo it then with the engine running and the heater on full blast (hot) not Aircon mode gently sqeeze the big pipe next to the radiator and it should start to move the air lock out of the system.

Hi I recently had a new radiator installed and then a new condenser on my 2003 2.4 Alphard. The heater isn't working so I thought I would top up the coolant, even though the engine temperature is completely normal. When I take off the cap and pour in new coolant, the plastic connector is leaking where it connects to the top of the radiator. Surely this is supposed to be sealed? I just can't get it to fit on properly. I have no idea if this is the reason the heater isn't working, but it might just be that the coolant is low and I can't top it up. Any thoughts?

The problem with the P3125 inverter fault code is that there is around 100 sub codes in the form of P3125-xxx. The sub code identifies which component, wiring, monitoring system is at fault. If you can get the full fault code read it will help you, Techstream will do this plus other JOBD readers might. C1259 and C1310 come on with a hybrid fault, as regenerative braking is no longer possible and the rear motor isolated, which is used for stability control, hence the VSC light. If there is a fault detected by the Skid Control Computer it will communicate this to the Hybrid Control Computer which will light the "red car !" and isolate the hybrid system from the skid control system. The same happens if the HV battery computer detects a fault or potential issue like a block abnormality.

Sorry just to confirm, you check drivers door side, passenger side and under the bonnet?

Yes just checked all fuse,s in dash and engine

Did you disconnect the battery before taking the earth wires off?