Code B335: Loss Of ECCP Serial Data
WARNING: This page is about a different car, the 1990 Buick Riviera and 1990 Buick Reatta. However, it is still accessible from the selected car via links, so may be relevant.
This code can only be viewed as a "history" code, because if it was current, service diagnostics could not be entered. Most likely the ECC controls for heating and A/C will also be inoperative when the loss of serial data occurs.
Since the serial data lines are redundant, a double open in the circuit No. 800 has to occur to set this code. However, the code will also set for a single open in the power or ground supply to the ECCP.
NOTE:
Loss of ECCP ground will cause data line circuit No. 800 to be tied to system voltage, disabling all vehicle self-diagnostics.