Volt

DTC P1EB9

The hybrid powertrain control module 2 activates the high-voltage energy management communication enable circuit when the vehicle is on. This circuit wakes-up the control modules for high-voltage energy bus communication.

The hybrid powertrain control module 2 detects a fault in the high- voltage energy management communication enable circuit.

DTC P1EB9 is a type A DTC.

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 following:

•	The control modules that share the K114B hybrid powertrain control module 2 terminal 48 X2 high-voltage energy management communication enable circuit

•	The control module B+, ignition and high-voltage energy management communication enable circuit terminals

1. Vehicle OFF, disconnect the X2 harness connector at the K114B hybrid powertrain control module 2.
2. Vehicle OFF, and all vehicle systems OFF, all keys at least 3 metres away from vehicle, all access doors closed. It may take up to 2 minutes for all vehicle systems to power down. Test for greater than 100 Ω, but less than infinite resistance, between the high-voltage energy management communication enable circuit terminal 48 X2 and earth.

⇒	If less than the specified range, refer to Testing the High-Voltage Energy Management Communication Enable Circuits for a Short-Circuit to Earth.

⇒	If infinite resistance, test the high-voltage energy management communication enable circuit for an open-circuit/high resistance.

3. Vehicle in Service Mode, verify that a test lamp illuminates between each B+ circuit terminal and earth.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, replace the K114B hybrid powertrain control module 2.

4. Vehicle in Service Mode, verify that a test lamp illuminates between each ignition circuit terminal and earth.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, replace the K114B hybrid powertrain control module 2.

5. If the circuits test normal, replace the K114B hybrid powertrain control module 2.

Testing the High-Voltage Energy Management Communication Enable Circuits for a Short-Circuit to Earth

1. Vehicle OFF, disconnect the X1 harness connector at the A4 hybrid/EV battery pack.
2. Vehicle OFF, and all vehicle systems OFF, all keys at least 3 metres away from vehicle, all access doors closed. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 100 Ω between the K114B hybrid powertrain control module 2 high-voltage energy management communication enable circuit terminal 48 X2 and earth.

⇒	If greater than the specified range, replace the A4 hybrid/EV battery pack.

3. Vehicle OFF, disconnect the X1 harness connector at the T18 battery charger.
4. Vehicle OFF, and all vehicle systems OFF, all keys at least 3 metres away from vehicle, all access doors closed. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 100 Ω between the K114B hybrid powertrain control module 2 high-voltage energy management communication enable circuit terminal 48 X2 and earth.

⇒	If greater than the specified range, replace the T18 battery charger.

5. Repair the short-circuit to earth on the high-voltage energy management communication enable circuit.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, programming and setup.