Volt

DTC P1EF8

The battery charger compares the high-voltage energy management communication enable hardwire signal with a hybrid powertrain control module 2 serial data message indicating that the high-voltage energy management communication enable signal is active. If the high-voltage energy management communication enable hardwire signal is low when the serial data message indicates it should be high, then DTC P1EF8 is set.

The control module is awake and communicating.

A short-circuit to earth or an open-circuit may exist on the high- voltage energy communication enable circuit.

DTC P1EF8 is a type A DTCs.

DTC P1EF8 is a type A DTCs.

Short-circuit to earth will also set multiple no communication codes for control modules on high-voltage energy serial data bus.

Schematic Reference

Connector End View Reference

Component Connector End Views

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Note: Use the schematic to identify the control modules B+, ignition, earth, communication enable and serial data circuit terminals.

1. Vehicle OFF, disconnect the X1 harness connector at the T18 battery charger.
2. Vehicle in Service Mode, verify that a test lamp illuminates between the high-voltage energy management communication enable circuit terminal G X1 and earth.

⇒	If the test lamp does not illuminate, test the circuit for a short-circuit to earth or open-circuit/high resistance. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.

3. Vehicle OFF, verify that a test lamp does not illuminate between the high-voltage energy management communication enable circuit terminal G X1 and earth.

⇒	If the test lamp illuminates, test the circuit for a short to voltage. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.

4. If all circuits test normal, replace the T18 battery charger.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, programming and setup