During a lapping day this weekend I got what I thought was axle hop under braking coming over a hill. Sometime later my speedo quit and the SES light came on. I slowed down for a cooldown lap and only made it halfway around the 2-mile track before it just quit. Got it started so's it was just barely running, then limped it back to the pits. Shut down, started again, and ran fine to get home (5 miles) but the SES light stayed on.

Car is a 92 LB9 T5. Haven't checked codes yet but pretty sure a 24 will show up. No obvious broken wires at the trans connectors, all a little oily. What else can I check?