is your's also not starting or did the light just come on and it seems to run fine? The 4cyl, from what i'm told doesn't have much in the way of diagnostics, but the odometer is set to trip the light on every 50,000 miles or so. there is a button on the back of the speedo that you have to reset. If you have higher miles and don't care about the light, they suggest removing the bulb.

'88 Raider. 2.6L dead...2.4L swap in progress, AT, 33's, 2 bouncy seat,AC, CC, 2.25 exh, 2" Tbar, 2" BL, rear DB, rear LSD,4.90's, SW hubs,gen2 uca's, KYB shocks, snorkel, elec fan, MSD.

'99 chev k3500 crewcab
'15 Subaru XV
'03 BMW i325