Hi all,

I have an AH20 E-four. The car is badged as such.

To date, the car has never knowingly engaged 4WD. I understand that a light comes on the dash when this happens, and no such light has ever come on.

If this is the case then either the 4WD has broken somewhere or someone, prior to my purchase, has slapped an E-four badge on the car to bump up its value (although the badge looks totally straight and spatially correct).

Is there any way of visually finding out whether the car has 4WD at all? If it does, what would be the areas to check if the 4WD is damaged?

I would have thought a look underneath would be the most certain way - is there a driveshaft or something on the rear wheels?

This is my definitely NOT 4WD 10 series for reference, with just the brake caliper attached to the rear wheel.

I hope this helps.

What's the first part of the chassis number?

The hybrid is the E-Four, that's ATH20.

The petrol version has a 4WD version which is the ANH25 (2.4l engine) or GGH25 (3.5l engine). As these aren't hybrids I believe it's a classic propshaft and mechanical differential box between the rear wheels. If it's an ANH20 or GGH20 then it doesn't have 4WD.

I think it's the same for the 10 series - ATH10 is E-Four, ANH15 and MNH15 are differential box, other 10s are 2WD.

If you do have an ATH20 there's an electric motor on the rear axle. I'd be very surprised for that to not work but nothing complaining.

Edited April 30Apr 30 by Ptarmigan

Thanks folks.

It's an ATH20. I took a look underneath and there indeed appears to be a motor on the axle and driveshafts by the wheels.

Also, there is no 4WD switch on the dash.

Weird.

I think that I'm going to need to ask a specialist mechanic to check it out.

The rear motor is just a normal part of the hybrid drive. Every time you accelerate, the rear motor will be used to get as much hybrid assistance as possible. If it wasn't working you would be getting warning lights on the dash.

That's my understanding too - it's more 'AWD' than '4WD', as in the power gets put down where it's needed. It's similar to EVs like 'dual motor' Teslas which have a motor on the front axle and another on the rear axle. I haven't looked into the rear motor setup but I don't think there is a lockable differential like you might get on an all-terrain vehicle. Like a Tesla, the second motor allows more electric power to be put down compared with only a single motor, as you have four tyres worth of grip instead of two (although the Alphard motors are nowhere near as powerful as Tesla's).

From what I read somewhere (don't have it to hand, may have been ATH10 rather than ATH20) there is a 4WD light but it only comes on when there is a fault. So the absence of a light means things are working normally.

ATH10 does have a 4WD light, but it purpose is to indicate a fault, as you state. The hybrid display on the stereo head unit shows the rear motor in use, but there is nothing similar on the ATH20.