check engine light

i took my truck to dropjaw mag in rockingham which is about a three hour drive for me and the truck did great there and back, but my check engine light did come on, which doesnt make sense because there is no computer in it at all so what is telling it to come on,,, truck runs great and drives great with no problems. just wondering what the light was on for.

Probably a service interval for some of the pollution control stuff.Reach under the dash where the service lites are and reverse the position of the female receptical for the check engine lite 180 degrees and the lite should go out.bj

can you show pictures of that? cuz i dunno what it is and mine runs fine and the light came on once for me too

i didn't know mazda had a service interval light...? but yeah, the light will come on for smog related stuff such as vacuum lines or failed sensors/wiring/fuses possibly