Isuzu MU-X Problems

This is an increasingly common complaint among car owners who are finding that modern driver safety aids such as autonomous emergency braking and lane-keeping assistance programs are too sensitive and don’t take into account the whole picture at the time. Examples include shrubs in a driveway causing the emergency braking to activate, and lane-keeping assistance trying to maintain a car in the centre of its lane despite a looming wide-load on a truck next to it.

I’m not sure what the solution is. But we can only hope that as cars get better and these programs more sophisticated, the errors won’t be as common. But while ever this tech relies on a computer and an algorithm, it will be doomed to (sometimes) fail. This is one of the reasons completely self-driving cars are not yet a reality on our roads; the tech is simply not foolproof yet.

Meantime, covering your car’s cameras with tape might put a stop to the false alarms, but it might also create new problems as the computer searches in vain for the camera’s input. And your concerns about insurance hassles are well founded, too. It’s not hard to imagine the owner of a car with disabled safety features being refused cover in the event of a crash.

My experiences with the very latest turbo-diesel engines available suggests that DPF burn offs are being programmed to happen much more often. It’s likely to be a manufacturer response to the problems associated with DPFs that become clogged and then require manual cleaning or even costly replacement. By programming the DPF to burn off more often, the theory is that this will lead to fewer DPF blockages and other problems, making life easier for the car’s owner and reducing customer complaints.

Perhaps another aspect of this is that the DPF burn usually takes several minutes and kilometres of driving to complete. If the vehicle is stopped before the burn is complete, it may try again for a complete regeneration (burn) as soon as possible, which could be why you’re seeing these frequent notifications on the dashboard.

Unlike some newer cars which use an electrically-operated park brake, this model Isuzu has a conventional, mechanical park brake set-up. So that’s a good start as the mechanical version is much simpler.

The tiny switch that is operated by the park brake lever (and lights up the warning light) can often fail or short-circuit, leaving the car thinking that the park brake is still applied even though it’s not. But if you’ve gone to the trouble of changing the wiring to the park brake lever, then presumably this switch was replaced, too. Or at least checked.

So the next thing to do is to make sure that the park brake is, indeed, releasing completely when you lower the park brake lever inside the cabin. If the park brake is poorly adjusted, you might find it’s not releasing all the way, and that’s what’s causing the problem. A quick squirt of contact cleaner on the switch would be your first move, however.

I’d be interested to know what happens after the 30 minutes when the system switches itself back on. Does it disable again if you give the connecting plug a wiggle? If so, it’s probably a poor electrical connection somewhere inside the plug assembly. If you need to turn the ignition off and back on to make the system disable itself again, then you might be dealing with some kind of computer (body computer?) problem.

The thing is, if this is a genuine Isuzu accessory option, then it should come under the car’s new-car warranty. At which point it’s Isuzu’s problem to fix, regardless of whether the dealership you use has seen this issue before or not.

This is an annoying but relatively common problem in many cars, not just the Isuzu. Because a car’s air-conditioning system dehumidifies the air (as well as cooling it) the water that was suspended in the air has to go somewhere. When everything’s working properly, there’s a small drain-hose from the air-con unit, through the floor to under the car where the water can be dumped with no problems.

But what often happens is that the little tube or drain-hose becomes blocked. At which point, the air from the atmosphere has nowhere to go other than inside the cabin where it causes the mayhem you’re experiencing. By locating the drain-tube and cleaning it out, the problem should go away. If not, you need to look more closely at the car’s heater matrix which also lives under the dashboard and can leak coolant into the cabin for a similar range of problems.

Electrical failures like this are not uncommon even on brand-new cars. You could have a problem with the body computer, the wiring system, the lock actuators, a fuse or relay or even the key fob that you use to control the locking. However, the solution is pretty simple: This car should still be under the factory warranty (even if you’re not the original owner) so all you need do is take it back to an Isuzu dealer. Under Australian Consumer Law (provided you haven’t caused the problem through negligence or mis-use) the manufacturer is responsible for fixing problems like this one at no cost to you.

A lot of people think that a car that is switched off and locked won’t be draining its battery at all. But that’s not the case. Electronic equipment often imposes a constant drain on the car’s battery, and things like the stereo (for keeping stored radio frequencies) and any alarm system can create a constant draw on the battery. And when you think about it, even the remote central locking needs to be 'alive' all the time so that it can identify and act on your command to open the doors and prepare the car to be started.

However, I wouldn’t expect a nearly new car battery to be unable to survive a single week of not being driven. So maybe there’s something else going on. It could even be that the battery itself is faulty and not holding a charge as it should.

I’d be talking to the dealership as a fault with, say, a luggage area light staying on or any other piece of equipment not switching off when it should, is potentially a warranty claim. Just don’t expect Isuzu to cover the cost of a new battery. Like tyres and brake pads, batteries are considered consumables and are generally not covered by a new-car warranty. Although if it’s an electrical fault on the car that has caused the death of the battery, I reckon it’s an arguable case.

The last decade of dual-cab four-wheel-drive utes have emerged as the tow-vehicles of choice, and you see them everywhere filling roles exactly like the one you have planned. Popular models include the Ford Ranger you’ve nominated, Toyota HiLux, Mazda BT-50, VW Amarok, Mitsubishi Triton, Nissan Navara and Isuzu D-Max. But there are also cheaper alternatives including makes like the South-Korean made Ssangyong and various Chinese brands like LDV and Great Wall.

Just make sure you know exactly how much you need to tow before making a decision as some of the cheaper models don’t have the same outright towing capacity and even if they do, some of them don’t have the engine performance to make towing as easy as it should be. For parts availability, the Toyota would be king in really remote areas, but any of the major brands are pretty well covered in Australia.

Meantime, don’t rule out ute-based wagons such as the Ford Everest, Isuzu MU-X, Mitsubishi Pajero Sport and Toyota Fortuna. These offer better ride comfort when unladen thanks to more sophisticated rear suspensions and most have as much or almost as much towing capacity as their ute brethren.

It’s difficult to be definitive here without actually driving the vehicle, but there are at least two possible sources for this. The first is the simplest and involves either a wheel and tyre or driveshaft that is out of balance. That should be easy to diagnose and fix.

The second possibility is that the vehicle’s driveline (engine, gearbox and transfer-case) has what’s called a resonant frequency that, when reached at a particular speed range, will result in some weird harmonics and vibrations which is possibly what you’re feeling and hearing. This becomes worse when the torque converter locks up (to save fuel) and there’s no slip in the driveline to absorb these bad vibes. By shifting back to fifth gear, you’re raising the engine revs and moving it out of that harmonic patch.

I’ve heard that Isuzu has been remapping some ECUs (on-board computers) to try to move this harmonic zone into a different (higher) speed range (by manipulating the torque-converter lock-up point) where it won’t be a problem to most owners. The fact is the Isuzu diesel has never been the most refined one out there and some vibrations and harmonics are relatively common, However, they shouldn’t be bad enough to ruin your enjoyment of the car.

In the old days, a different exhaust was often enough to move the harmonics around or get rid of them altogether, but I can understand why that’s not really an option on a brand-new vehicle.