Isuzu FYH Pricing and Specs

The digital displays on modern cars are known to sometimes randomly fail for no apparent reason. Sometimes it’s the whole display that fritzes, other times just a smaller part of the display will disappear. Usually, replacing the LED module is the fix.

From memory, this model D-Max groups the fuel and temperature gauges, odometer and the gear position information into a small unit in the middle of the dash binnacle. Which means it might be a bit complicated re-connecting the temperature and fuel tank sensor units to the new module, as well as making sure the new odometer reads the correct mileage for the vehicle. An auto electrician should be able to handle it, though.

Technically, of course, any car without a working gear-position indicator is unroadworthy, so this needs to be fixed rather than ignored.

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.

This is a tricky one because the D-Max’s SVS warning light seems to be a bit of an all-rounder. That is, it indicates a fault, but a non-specific one. Certainly not one that can be read by the majority of aftermarket scanning tools. Logic suggests there’s something within the driveline that is getting too hot for the computer’s liking, a theory backed up by the fact that it only triggers when you’re towing a big load and the car is working its hardest.

The solution seems to be to present the car at an Isuzu dealership as this may be the only workshop that will have the D-Max-specific scanning gear to determine the cause or even narrow it down.

For the record, the SVS stands for Service Vehicle Soon, but I’m afraid even that’s a fairly generic recommendation and doesn’t get you any closer to the cause. That said, when engine oil or transmission fluid gets beyond a certain temperature, the computer will often detect this and call for a change of fluids as a means of driveline protection. This could be what’s happening every time you tow.