Just got down putting a built 355 in, rebuilding the tranny, and put in an ed wright custom chip......... now working out the bugs...... well when im driving in fifth gear, the Up shift light comes on!!!!!!! WHY??? and it didnt use to either! is something not hooked up right?

 

I have heard of it happening if you change your rear gear ratio.

 

yeah the shift light goes by engine rpm's, speed and cluch pedel sensor, If you change the gears it screws everything up, just pull the light bulb out.

 

Its telling you that you need a 6 speed trans.

~M~

 

Most likely Ed Wrights chip. I remeber comming across a similar problem when I was burning my own chips. At 80 mph my shift lite would come on. I found one of the tables in tunercat was at 80mph (something for automatic tranny), and changed to zero. My lite stayed on all the time, so I adjusted to 255 or whatever max mph was, and my lite hast given me a problem. Im not positive that this is your problem, but If you didnt have problem before, than its most likely in the chip. I would call Wright, he a friendly guy with a good amount of experience.

 

Its the PROM. Someone forgot to factor in the ratio of engine RPM (dist ref pulses) to the VSS and eliminate the "SHIFT" output at ratios over 1:1. OOPS!