Isuzu Problems

It sounds very much like the vehicle has gone into limp-home mode. This is a self-preservation system whereby the engine and drastically reduces the power it’s producing, limits top speed and often locks the transmission into a low gear. Something has happened that has caused this, and a common reason is that something in the engine, fuel system, or (more likely) the transmission has started to get too hot with the strain of towing.

With luck, full operation will be restored once the vehicle has been allowed to cool down. But you may need to visit a dealership to have things reset. It’s always a good idea to do a full engine and transmission fluid and filter change after any overheating event anyway.

The list of possible causes for a modern turbo-diesel engine not to start would fill a pretty large book, and there’s no point trying to guess the problem. If the engine is cranking but nothing else is happening, most mechanics will start by looking at the fuel system. There could be a problem with the tank pick-up, the fuel rail, the injectors, the filters and many more components. But a check of the fuel delivery pressure and volume is a good place to start.

But this is not a job for the amateur in their driveway. Modern diesels use super high injector pressures, and, if there’s any residual pressure in the system when you crack it open, that pressure is enough to remove fingers, just like a high-pressure water jet can cut steel.

Cars are often less than perfect and problems can show up once they are released on to a particular market with particular conditions. But every new make and model that hits the road and is eligible for registration has to pass a range of tests and certifications before the government will allow that to happen. So your question is really one for government, but the reality is that in many cases, nobody can see these problems coming.

Meanwhile, while I won’t speak for every `information’ source on the internet, I can say without fear of contradiction that no road tester or writer for Carsguide accepts payments from car importers for their opinion. Social media influencers may be a different matter, but I promise you that anything published on Carsguide is the truth and in no way influenced by the car maker or importer. We now live in an age where you need to be very careful where you source your information, but Cargsuide is one source you can trust. It’s something the writers (my colleagues) are very proud of.

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.

Let’s start at the start. The SVS light on your car stands for 'Service Vehicle Soon'. Fundamentally, it’s telling you that something is not right somewhere on the vehicle and the computer has logged the fault. That’s why a scan showed up the code PO661.

On this vehicle, code PO661 relates to the electronics that control the swirl valve inside the intake manifold. This valve works to create the maximum gas velocity inside the intake runners and, therefore, gain the cleanest, most complete burn of the fuel and air entering the engine. If this valve is not operating properly, you may find a loss of power as the turbocharger won’t be working at its most efficient. In some cases, the same fault code can show up because of a problem with the engine’s EGR valve which is also part of the engine’s intake system. This may require the manifold to be removed and manually cleaned.

However, it’s unlikely to be anything to do with the car’s air-conditioning system, which is more likely to be a coincidence. That said, if the engine is running hotter than normal because the intake system is not working properly, then the car may have an interlock that prevents the air-con coming on to help keep coolant temperatures at bay.

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.

It’s not a problem we’ve heard of occurring in huge numbers, but like any component, a canopy is subject to wear and tear just like any other. Canopies on tradie-trucks can cop an awful hammering at the hands of their owners and damage is inevitable in such cases. Even a few years exposure to Australian levels of UV radiation can cause a canopy to start to break down structurally, so they generally have a finite lifespan.

But instead of replacing the whole canopy (assuming it’s a fibreglass one) it might be worth asking a fibreglass specialist (say, a boat repairer) if the crack can be repaired. That would certainly be cheaper than replacing the whole canopy

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.