Here it is...
VT/VX Hidden Data
A string of useful data is hidden in the Holden VT/VX trip computer display...
Do you own a VT or VX series Holden? Do you have a thirst for information? If the answer is "yes" then take a look at the 'hidden' displays in the factory trip computer...
Depending on the spec of your VT/VX Holden, a single window or triple window trip computer will be installed. The basic single window computer offers an odometer, trip meter, distance to empty, service reminder and an overspeed alert. Upmarket three window models add average road speed, average fuel consumption, fuel used, instantaneous fuel consumption and trip time.
The Holden owner's handbook instructs those who are "technically minded" how to customise the trip computer display to your personal preferences. However, beyond this are some 'hidden' displays that are not printed in the handbook or even in Holden's service manuals...
Let's take a look at how to find these hidden goodies!
To gain access to the hidden displays you need to hold down the trip computer's Mode and Up buttons while the ignition is switched off. Then simply start the car and release the buttons and you've found 'em!
There are several displays that can be scrolled through by repeatedly pressing the Mode button.
The hidden display for coolant temperature is particularly useful. Ever wondered what the actual coolant temp is when the needle moves off zero or is halfway? Simply start the car from cold and watch the relationship between the coolant needle and the numerical display. The engine should warm up to around 90 degrees Celsius.
When the letter F appears with a number alongside you know you're looking at the precise number of litres of fuel remaining in the tank. There is also another F display with a l/hr appendage - this is the instantaneous fuel consumption. At idle, fuel consumption should be in the vicinity of 1.5 litres per hour.
The display seen here is for battery voltage. There should be around 14-volts being shown with the engine running. The display that follows should show 5.0-volts; we believe this is related to the instrument cluster.
The 'all on' display is useful for general faultfinding. This function sends the speedo needle to 100 km/h, the tacho needle to 3000 rpm, illuminates all of the warning lights and display segments and sounds the overspeed buzzer. What good is this, you ask? Well - as an example - it would let you determine whether you have a blown oil pressure bulb.
There are also some less useful displays that are accessible, such as numerical road speed, numerical engine revs (which is difficult to read due a very fast update rate, as seen here) and a VIN display.
Unfortunately, there remain a few displays that we haven't been able to decipher. One shows the letters PN followed by a number, while another shows the letter t followed by 00. There is also a display that contains the letters vP followed by a constantly changing number; we have no idea what that means.
Finally, the display that reads P OFF presumably isn't telling you 'where to go', but indicates that the "police mode" is not activated. We're told only a TEC2 tool can access this mode and its function is unknown.
So there you go Holden VT/VX owners - your trip computer display is home to an array of displays you never knew you had. Now get out into the garage and try them for yourself!
