U1255 Class 2 Initialization Error

Circuit Description:
The PZM requests information from other modules on the Class 2 serial data line when the vehicle is started.

DTC Will Set When:
The PZM requests information and the module which has that information is not "on-line."

Action Taken (By PZM):
The PZM will use default values for the information that it was requesting.

DTC Will Clear When:
The module with the information the PZM is requesting comes back "on-line."

Troubleshooting Hints:
1. If DTC U1255 is set, Clear DTCs and Cycle ignition. If DTC U1255 is still current, ensure that all the modules are functioning properly by establishing communications with each module on the Class 2 Data Bus.
2. Check CKT 1807 (PPL) for a intermittent open.
3. If OK, replace the PZM.