I had a new tranny put into my '88 K 1500 (700R4/4L60) and was testing it out. About a half hour into the drive, the speedometer suddenly stopped working and the Brake light on the dash started to flicker. The speedo came back on a few minutes later, but the brake light kept flashing, four quick pulses and one long, four short, one long. Everything worked fine so I kept going and checked the codes when I got home, nothing. So I read the book and could not find any reference to diognostic codes through the dash Brake light, although this does have early Antiloc (Back wheels only and in 2WD only). Finally, I disconnected the battery and the code cleared. Anyone ever hear of anything like that?

 

I never had or heard of that problem but I will note it in my manual. Thanks