My car (91 LB9 305 T5 7730 ECM) started throwing code 24 VSS after I sent out my prom to be reflashed. I had the vats, and emissions stuff burned out. Now I don't know jack squat about tuning these proms but I'm starting to think that this is not just a coincidence. Could my reflashed chip be missing something in the program to operate the VSS. My speedo and odo still work fine and the dummy light only comes on after I drive it up to speed then let it decel.

 

There are many tests being made in the code before reporting an Err 24, but it's generally due to no VSS pulses detected during decel, which is apparently what is causing the CEL to illuminate. Without your being able to upload your bin, it's hard to determine where the problem lies -- is it a bin setting or a mechanical issue?

 

Well I've tried 2 different ECU's and 2 different VSS sensors. I have a hard time believing that it's mechanical at this point. Would an ALDL cable and some data logging software be of any value to find out what's going on in there?

 

With the speedometer working, the VSS, wiring, and ECM is OK. Bottom line is that your tuner did something wrong in the re-burn. Being a DIY board this is between you and your tuner to correct, we are not here to support tuners that are being paid.

RBob.