Volt

DTC P0AA1, P0AD9, P0ADD, P0AE2, P0AE4, P0D0A, P0D11, P1EBC-P1EBF, P1EC0 or P1EC3-P1EC5

The hybrid/EV battery contains 5 high-voltage contactors and 2 transistors. The high-voltage contactors allow the high-voltage DC batteries to be connected to the vehicle or safely contain the high-voltage DC within the hybrid/EV battery assembly. The 5 high-voltage contactors are a main positive high-voltage contactor, main negative high-voltage contactor, charge positive high-voltage contactor, charge negative high-voltage contactor and multi-function high-voltage contactor. The 2 transistors are the precharge transistor and heater transistor. These contactors/transistors close and open in sequence and are controlled by the hybrid/EV powertrain control module 2. The hybrid/EV powertrain control module 2 supplies voltage to the control circuit for the high-voltage contactors/transistors. Earth is provided through the case earth.

P0AA1

P0AD9, P0ADD, P0AE4, P0D0A, P0D11 and P1EBC

The 12 V battery voltage is greater than 10 V.

P0AE2

P1EBD or P1EBE

P1EBF

CHARGE MODE

BATTERY HEATING ONLY MODE

P1EC0

P1EC3

P1EC4

P1EC5

P0AA1 and P0AE2

The bus voltage is measured to be greater than 80% of battery voltage.

P0AD9, P0ADD, P0AE4, P0D0A, P0D11 and P1EBC

The hybrid/EV powertrain control module 2 has detected an open or short-circuit to voltage in the control circuit for the corresponding contactor.

P1EBD

P1EBE

The Accumulated Battery Current greater than 100 A has been detected for 4 seconds.

P1EBF

CHARGE MODE

The charger high-voltage output is greater than 130 V for the first 300 ms of the charger precharge mode.

OR

BATTERY HEATING ONLY MODE

Battery current of more than 1 A is detected at the charger during battery heater only mode.

P1EC0

The main bus voltage is less than 80% of battery voltage.

P1EC3

The hybrid/EV powertrain control module 2 has detected a fault in the heater transistor control circuit.

P1EC4

The total Accumulated Battery Current difference between the battery charger output current and the battery charging current after 4 seconds is less than 200 A.

P1EC5

The battery charger sensed current is greater than 0.4 A during the battery charger precharge mode with the multi-function and heater transistor commanded OFF.

Note: If the high-voltage contactors opened while under high-current load, replace the drive motor battery wire junction block relay. The following conditions could cause the high-voltage contactors to open while under high-current load:

Schematic Reference

Hybrid Energy Storage Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Drive Motor Battery System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

EL-48900 HEV Safety Kit

For equivalent regional tools, refer to Special Tools .

1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling .
2. Connect the 12 V battery.
3. Vehicle in Service Mode, verify that DTC P0AE2, P0AE4, P1EC3, P1EC4 or P1EC5 is not set.

⇒	If DTC P0AE2 or P0AE4 is set, refer to Hybrid/EV Battery Precharge Transistor Diagnosis.

⇒	If DTC P1EC3, P1EC4 or P1EC5 is set, refer to Hybrid/EV Battery Pack Heater Transistor Diagnosis.

4. Command the Hybrid/EV Battery Negative Contactor OPEN and CLOSED with a scan tool while listening for the contactor to open and close. The Hybrid/EV Battery Negative Contactor should be heard opening and closing.

⇒	If the Hybrid/EV Battery Negative Contactor does not open and close, refer to Hybrid/EV Battery Negative Contactor Diagnosis.

5. Command the Hybrid/EV Battery Positive Contactor OPEN and CLOSED with a scan tool while listening for the contactor to open and close. The Hybrid/EV Battery Positive Contactor should be heard opening and closing.

⇒	If the Hybrid/EV Battery Positive Contactor does not open and close, refer to Hybrid/EV Battery Positive Contactor Diagnosis.

6. Command the Battery Charging System Negative Contactor OPEN and CLOSED with a scan tool while listening for the contactor to open and close. The Battery Charging System Negative Contactor should be heard opening and closing.

⇒	If the Hybrid/EV Battery Negative Contactor does not open and close, refer to Battery Charging System Negative Contactor Diagnosis.

7. Command the Battery Charging System Positive Contactor OPEN and CLOSED with a scan tool while listening for the contactor to open and close. The Battery Charging System Positive Contactor should be heard opening and closing.

⇒	If the Battery Charging System Positive Contactor does not open and close, refer to Battery Charging System Positive Contactor Diagnosis.

8. Command the Hybrid/EV Battery Multifunction Contactor OPEN and CLOSED with a scan tool while listening for the contactor to open and close. The Hybrid/EV Battery Multifunction Contactor should be heard opening and closing.

⇒	If the Hybrid/EV Battery Multi-function Contactor does not open and close, refer to Hybrid/EV Battery Multifunction Contactor Diagnosis.

P0AE2 or P0AE4 - Hybrid/EV Battery Precharge Transistor Diagnosis

Danger: High voltage enabling and disabling shall be only performed by High Voltage Qualified Technicians. The procedures for high-voltage enabling/disabling can be found in the service instructions and must be strictly followed at all times. The usage of the Protocol High Voltage Disabling/Enabling is mandatory. The High-Voltage Qualified Technician is responsible for the adherence to the manufacturer's service instructions as well as current national legal regulations.

Failure to follow the procedures exactly as written may result in serious injury or death.
Questions regarding training can be answered by your national training centre.

Danger: Any hybrid/EV battery pack replacement shall be performed by High-Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High-Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior to removal of the battery pack.

1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling .
2. Connect the 12 V battery.
3. Disconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.
4. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 Ω between the ground circuit terminal 5 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

5. Verify that a test lamp illuminates between the B+ circuit terminal 9 and ground.

⇒	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 A4 hybrid/EV battery pack.

6. Reconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.

Note: If connectors X1 and X2 were disconnected during the disabling procedure, reconnect X1 before commanding the contactor closed.

7. Vehicle in Service Mode, command the Hybrid/EV Battery Pack Precharge Transistor CLOSED.

Note: Ignore DTC P0AD9, P0ADD, P0AE4, P0D0A, P0D11, P1EBC or P1EC3 when disconnecting the X1 connector with the Vehicle in Service Mode.

8. Disconnect the X1 harness connector at the A28 hybrid/EV battery contactor assembly.
9. Connect a test lamp between control circuit terminal 11 and earth.
10. Vehicle in Service Mode, command the Hybrid/EV Battery Pack Precharge Transistor OPEN and CLOSED with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

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

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the hybrid powertrain control module 2.

11. If all circuits test normal, replace the A4 hybrid/EV battery pack.

P1EC3, P1EC4, or P1EC5 - Hybrid/EV Battery Pack Heater Transistor Diagnosis

Danger: High voltage enabling and disabling shall be only performed by High Voltage Qualified Technicians. The procedures for high-voltage enabling/disabling can be found in the service instructions and must be strictly followed at all times. The usage of the Protocol High Voltage Disabling/Enabling is mandatory. The High-Voltage Qualified Technician is responsible for the adherence to the manufacturer's service instructions as well as current national legal regulations.

Failure to follow the procedures exactly as written may result in serious injury or death.
Questions regarding training can be answered by your national training centre.

Danger: Any hybrid/EV battery pack replacement shall be performed by High-Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High-Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior to removal of the battery pack.

1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling .
2. Connect the 12 V battery.
3. Disconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.
4. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 Ω between the ground circuit terminal 5 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

5. Verify that a test lamp illuminates between the B+ circuit terminal 9 and ground.

⇒	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 A4 hybrid/EV battery pack.

6. Vehicle in Service Mode, test for less than 1 V between the control circuit terminal 2 harness connector at the A28 hybrid battery contactor assembly and earth.

⇒	If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.

7. Vehicle OFF, test for infinite resistance between control circuit terminal 2 harness connector at the A28 hybrid battery contactor assembly and earth.

⇒	If less than the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.

8. Disconnect the X2 harness connector at the K114B hybrid powertrain control module 2.
9. Test for less than 2 Ω in the control circuit end to end between terminal 2 X2 harness connector at the A28 hybrid battery contactor assembly and terminal 54 X2 harness connector at the K114B hybrid powertrain control module 2.

⇒	If greater than the specified range, test the control circuit for an open/high resistance.

10. If all circuits test normal, replace the K114B hybrid/EV powertrain control module 2. If the DTC resets, replace the A4 hybrid/EV battery pack.

P1EC0 - Hybrid/EV Battery System Contactors Stuck Open Diagnosis

Danger: High voltage enabling and disabling shall be only performed by High Voltage Qualified Technicians. The procedures for high-voltage enabling/disabling can be found in the service instructions and must be strictly followed at all times. The usage of the Protocol High Voltage Disabling/Enabling is mandatory. The High-Voltage Qualified Technician is responsible for the adherence to the manufacturer's service instructions as well as current national legal regulations.

Failure to follow the procedures exactly as written may result in serious injury or death.
Questions regarding training can be answered by your national training centre.

Danger: Any hybrid/EV battery pack replacement shall be performed by High-Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High-Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior to removal of the battery pack.

1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling .
2. Connect the 12 V battery.
3. Disconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.
4. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 Ω between the ground circuit terminal 5 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

5. Verify that a test lamp illuminates between the B+ circuit terminal 9 and ground.

⇒	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 A4 hybrid/EV battery pack.

6. Reconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.

Note: If connectors X1 and X2 were disconnected during the disabling procedure, reconnect X1 before commanding the contactor closed.

7. Vehicle in Service Mode, command the Hybrid/EV Battery Negative Contactor CLOSED.

Note: Ignore DTC P0AD9, P0ADD, P0AE4, P0D0A, P0D11, P1EBC or P1EC3 when disconnecting the X1 connector with the Vehicle in Service Mode.

8. Disconnect the X1 harness connector at the A28 hybrid/EV battery contactor assembly.
9. Connect a test lamp between control circuit terminal 4 and ground.
10. Vehicle in Service Mode, command the Hybrid/EV Battery Negative Contactor OPEN and CLOSED with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

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

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the hybrid powertrain control module 2.

11. Connect a test lamp between control circuit terminal 2 and ground.
12. Command the Hybrid/EV Battery Positive Contactor OPEN and CLOSED with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

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

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the hybrid powertrain control module 2.

13. If all circuits test normal, replace the A4 hybrid/EV battery pack.

P0ADD - Hybrid/EV Battery Negative Contactor Diagnosis

Danger: High voltage enabling and disabling shall be only performed by High Voltage Qualified Technicians. The procedures for high-voltage enabling/disabling can be found in the service instructions and must be strictly followed at all times. The usage of the Protocol High Voltage Disabling/Enabling is mandatory. The High-Voltage Qualified Technician is responsible for the adherence to the manufacturer's service instructions as well as current national legal regulations.

Failure to follow the procedures exactly as written may result in serious injury or death.
Questions regarding training can be answered by your national training centre.

Danger: Any hybrid/EV battery pack replacement shall be performed by High-Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High-Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior to removal of the battery pack.

1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling .
2. Connect the 12 V battery.
3. Disconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.
4. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 Ω between the ground circuit terminal 5 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

5. Verify that a test lamp illuminates between the B+ circuit terminal 9 and ground.

⇒	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 A4 hybrid/EV battery pack.

6. Reconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.

Note: If connectors X1 and X2 were disconnected during the disabling procedure, reconnect X1 before commanding the contactor closed.

7. Vehicle in Service Mode, command the Hybrid/EV Battery Negative Contactor CLOSED.

Note: Ignore DTC P0AD9, P0ADD, P0AE4, P0D0A, P0D11, P1EBC or P1EC3 when disconnecting the X1 connector with the Vehicle in Service Mode.

8. Disconnect the X1 harness connector at the A28 hybrid/EV battery contactor assembly.
9. Connect a test lamp between control circuit terminal 4 and ground.
10. Vehicle in Service Mode, command the Hybrid/EV Battery Negative Contactor OPEN and CLOSED with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

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

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the hybrid powertrain control module 2.

11. If all circuits test normal, replace the A4 hybrid/EV battery pack.

P0AA1 or P0AD9 - Hybrid/EV Battery Positive Contactor Diagnosis

Danger: High voltage enabling and disabling shall be only performed by High Voltage Qualified Technicians. The procedures for high-voltage enabling/disabling can be found in the service instructions and must be strictly followed at all times. The usage of the Protocol High Voltage Disabling/Enabling is mandatory. The High-Voltage Qualified Technician is responsible for the adherence to the manufacturer's service instructions as well as current national legal regulations.

Failure to follow the procedures exactly as written may result in serious injury or death.
Questions regarding training can be answered by your national training centre.

Danger: Any hybrid/EV battery pack replacement shall be performed by High-Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High-Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior to removal of the battery pack.

1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling .
2. Connect the 12 V battery.
3. Disconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.
4. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 Ω between the ground circuit terminal 5 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

5. Verify that a test lamp illuminates between the B+ circuit terminal 9 and ground.

⇒	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 A4 hybrid/EV battery pack.

6. Reconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.

Note: If connectors X1 and X2 were disconnected during the disabling procedure, reconnect X1 before commanding the contactor closed.

7. Vehicle in Service Mode, command the Hybrid/EV Battery Positive Contactor CLOSED.

Note: Ignore DTC P0AD9, P0ADD, P0AE4, P0D0A, P0D11, P1EBC or P1EC3 when disconnecting the X1 connector with the Vehicle in Service Mode.

8. Disconnect the X1 harness connector at the A28 hybrid/EV battery contactor assembly.
9. Connect a test lamp between control circuit terminal 2 and ground.
10. Command the Hybrid/EV Battery Positive Contactor OPEN and CLOSED with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

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

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the hybrid powertrain control module 2.

11. If all circuits test normal, replace the A4 hybrid/EV battery pack.

P1EBD - Battery Charging System Contactors Stuck Open Diagnosis

Danger: High voltage enabling and disabling shall be only performed by High Voltage Qualified Technicians. The procedures for high-voltage enabling/disabling can be found in the service instructions and must be strictly followed at all times. The usage of the Protocol High Voltage Disabling/Enabling is mandatory. The High-Voltage Qualified Technician is responsible for the adherence to the manufacturer's service instructions as well as current national legal regulations.

Failure to follow the procedures exactly as written may result in serious injury or death.
Questions regarding training can be answered by your national training centre.

Danger: Any hybrid/EV battery pack replacement shall be performed by High-Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High-Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior to removal of the battery pack.

1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling .
2. Connect the 12 V battery.
3. Disconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.
4. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 Ω between the ground circuit terminal 5 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

5. Verify that a test lamp illuminates between the B+ circuit terminal 9 and ground.

⇒	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 A4 hybrid/EV battery pack.

6. Reconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.

Note: If connectors X1 and X2 were disconnected during the disabling procedure, reconnect X1 before commanding the contactor closed.

7. Vehicle in Service Mode, command the Battery Charging System Negative Contactor CLOSED.

Note: Ignore DTC P0AD9, P0ADD, P0AE4, P0D0A, P0D11, P1EBC or P1EC3 when disconnecting the X1 connector with the Vehicle in Service Mode.

8. Disconnect the X1 harness connector at the A28 hybrid/EV battery contactor assembly.
9. Connect a test lamp between control circuit terminal 9 and earth.
10. Command the Battery Charging System Negative Contactor OPEN and CLOSED with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

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

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the hybrid powertrain control module 2.

11. Connect a test lamp between control circuit terminal 7 and earth.
12. Command the Battery Charging System Positive Contactor OPEN and CLOSED with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

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

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the hybrid powertrain control module 2.

13. If all circuits test normal, replace the A4 hybrid/EV battery pack.

P0D11 - Battery Charging System Negative Contactor Diagnosis

Danger: High voltage enabling and disabling shall be only performed by High Voltage Qualified Technicians. The procedures for high-voltage enabling/disabling can be found in the service instructions and must be strictly followed at all times. The usage of the Protocol High Voltage Disabling/Enabling is mandatory. The High-Voltage Qualified Technician is responsible for the adherence to the manufacturer's service instructions as well as current national legal regulations.

Failure to follow the procedures exactly as written may result in serious injury or death.
Questions regarding training can be answered by your national training centre.

Danger: Any hybrid/EV battery pack replacement shall be performed by High-Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High-Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior to removal of the battery pack.

1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling .
2. Connect the 12 V battery.
3. Disconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.
4. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 Ω between the ground circuit terminal 5 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

5. Verify that a test lamp illuminates between the B+ circuit terminal 9 and ground.

⇒	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 A4 hybrid/EV battery pack.

6. Reconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.

Note: If connectors X1 and X2 were disconnected during the disabling procedure, reconnect X1 before commanding the contactor closed.

7. Vehicle in Service Mode, command the Battery Charging System Negative Contactor CLOSED.

Note: Ignore DTC P0AD9, P0ADD, P0AE4, P0D0A, P0D11, P1EBC or P1EC3 when disconnecting the X1 connector with the Vehicle in Service Mode.

8. Disconnect the X1 harness connector at the A28 hybrid/EV battery contactor assembly.
9. Connect a test lamp between control circuit terminal 9 and earth.
10. Command the Battery Charging System Negative Contactor OPEN and CLOSED with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

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

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the hybrid powertrain control module 2.

11. If all circuits test normal, replace the A4 hybrid/EV battery pack.

P0D0A - Battery Charging System Positive Contactor Diagnosis

Danger: High voltage enabling and disabling shall be only performed by High Voltage Qualified Technicians. The procedures for high-voltage enabling/disabling can be found in the service instructions and must be strictly followed at all times. The usage of the Protocol High Voltage Disabling/Enabling is mandatory. The High-Voltage Qualified Technician is responsible for the adherence to the manufacturer's service instructions as well as current national legal regulations.

Failure to follow the procedures exactly as written may result in serious injury or death.
Questions regarding training can be answered by your national training centre.

Danger: Any hybrid/EV battery pack replacement shall be performed by High-Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High-Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior to removal of the battery pack.

1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling .
2. Connect the 12 V battery.
3. Disconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.
4. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 Ω between the ground circuit terminal 5 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

5. Verify that a test lamp illuminates between the B+ circuit terminal 9 and ground.

⇒	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 A4 hybrid/EV battery pack.

6. Reconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.

Note: If connectors X1 and X2 were disconnected during the disabling procedure, reconnect X1 before commanding the contactor closed.

7. Vehicle in Service Mode, command the Battery Charging System Negative Contactor CLOSED.

Note: Ignore DTC P0AD9, P0ADD, P0AE4, P0D0A, P0D11, P1EBC or P1EC3 when disconnecting the X1 connector with the Vehicle in Service Mode.

8. Disconnect the X1 harness connector at the A28 hybrid/EV battery contactor assembly.
9. Connect a test lamp between control circuit terminal 7 and earth.
10. Command the Battery Charging System Positive Contactor OPEN and CLOSED with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

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

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the hybrid powertrain control module 2.

11. If all circuits test normal, replace the A4 hybrid/EV battery pack.

P1EBC, P1EBE or P1EBF - Hybrid/EV Battery Multifunction Contactor Diagnosis

Danger: High voltage enabling and disabling shall be only performed by High Voltage Qualified Technicians. The procedures for high-voltage enabling/disabling can be found in the service instructions and must be strictly followed at all times. The usage of the Protocol High Voltage Disabling/Enabling is mandatory. The High-Voltage Qualified Technician is responsible for the adherence to the manufacturer's service instructions as well as current national legal regulations.

Failure to follow the procedures exactly as written may result in serious injury or death.
Questions regarding training can be answered by your national training centre.

Danger: Any hybrid/EV battery pack replacement shall be performed by High-Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High-Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior to removal of the battery pack.

1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling .
2. Connect the 12 V battery.
3. Disconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.
4. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 Ω between the ground circuit terminal 5 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

5. Verify that a test lamp illuminates between the B+ circuit terminal 9 and ground.

⇒	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 A4 hybrid/EV battery pack.

6. Reconnect the X2 harness connector at the A28 hybrid/EV battery contactor assembly.

Note: If connectors X1 and X2 were disconnected during the disabling procedure, reconnect X1 before commanding the contactor closed.

7. Vehicle in Service Mode, command the Hybrid/EV Battery Multi-function Contactor CLOSED.

Note: Ignore DTC P0AD9, P0ADD, P0AE4, P0D0A, P0D11, P1EBC or P1EC3 when disconnecting the X1 connector with the Vehicle in Service Mode.

8. Disconnect the X1 harness connector at the A28 hybrid/EV battery contactor assembly.
9. Connect a test lamp between control circuit terminal 6 and earth.
10. Command the Hybrid/EV Battery Multifunction Contactor OPEN and CLOSED with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

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

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the hybrid powertrain control module 2.

11. If all circuits test normal, replace the A4 hybrid/EV battery pack.

Perform the Diagnostic Repair Verification after completing the repair.