The Territory is pretty well known in the fixit trade for having various transmission problems. Perhaps the most common was a failure of the entire transmission due to coolant from the transmission cooler mixing with the transmission fluid inside the gearbox. When that happened, the destruction was fairly complete with ruined electronics and internal hardware as the contaminated fluid could no longer satisfactorily lubricate the gearbox’s many moving parts. A whole new transmission was the usual outcome.

The first sign of this was usually milky transmission fluid (caused by the water mixing with the oil) but by then, the damage was often already done. This was more of a problem with the later model Territories with the six-speed ZF automatic transmission.

The first thing to do is get your mechanic to drive the vehicle when it’s hot. Arrange a time and then deliver the car at that time with everything up to full operating temperature. Otherwise, the problem isn’t going to show up when it needs to.

While there are lots and lots of things that can cause this sort of behaviour, it does sound like something in the actual powertrain is the problem. That’s because the shuddering goes away when you drop the transmission into neutral and let the vehicle coast to a stop. If the problem was a wheel, a wheel bearing, axle, brake problem or an out-of-balance driveshaft, the problem would continue even though you were coasting.

You may have a problem with something inside the transmission itself, way too much backlash somewhere in the driveline or a problem with the torque converter. Either way, you need to have your mechanic experience the problem or everybody is simply guessing.

It’s serious inasmuch as it’s pointing to a problem with the car’s anti-lock brakes which are a critical safety system on any car. It could be caused by a faulty ABS module (which is the component that physically modulates the brake pressure to avoid the wheels locking up). But it could also be the fault of a sensor somewhere on the car. You may even find something as random as low battery voltage can trigger this sort of alert.

It could even be a simple leak in the system that has allowed the brake fluid to fall below the minimum level. So start with that and check the contents of the brake master cylinder under the bonnet. If that’s okay, a brake specialist is probably your best bet.