The Jackaroo, as with all vehicles intended to be supplied to the USA market, (as the Isuzu Trooper) is fitted with OnBoard Diagnostics (OBD) to enable rudimentary servicing of the vehicle by non dealer mechanics. It was introduced in the USA as a mandatory requirement in 1996 to ensure that air pollution standards could be maintained. The MIL (Malfunction Indicator Lamp) or commonly labelled Check Engine light is located in the instrument cluster.
(Download the full tip here – “How to Read Your Jackaroo Fault Codes” )