U1064 Loss Of Serial Data Communication (PZM) - Cell Phone

DTC U1064-Loss Of Serial Data Communication (PZM):

CIRCUIT DESCRIPTION
While the ignition switch is in RUN, modules communicating on the Class 2 Serial Data Line send a State of Health (SOH) message every 2 seconds to ensure hat the system is operating properly.

DTC WILL SET WHEN
The cellular telephone module does not receive a SOH message from the PZM after three consecutive monitoring cycles.

DTC WILL CLEAR WHEN
The PZM transmits a SOH message to the cellular telephone module.

TROUBLESHOOTING HINTS
1. If there are multiple Class 2 DTCs (i.e. DTCs U1096, U1128, U1129), check for an intermittent short to power or ground in CKT 1807 (PPL).
2. If DTC is current, attempt to establish communication with the PZM using a scan tool.
^ If communication cannot be established with the PZM, refer to Body Control Module (PZM) Diagnosis. Body Control Module
^ If communication can be established with the PZM, replace Cellular Telephone Module.
3. If the DTC is history, check for an intermittent open in CKT 1807 (PPL).