Service Information

Volt

DTC P0641-P0643 or P0651-P0653

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC P0641: 5 V Reference 1 Circuit - Main

DTC P0642: 5 V Reference 1 Circuit Low Voltage

DTC P0643: 5 V Reference 1 Circuit High Voltage

DTC P0651: 5 V Reference 2 Circuit - Charger

DTC P0652: 5 V Reference 2 Circuit Low Voltage

DTC P0653: 5 V Reference 2 Circuit High Voltage

Circuit/System Description

The high-voltage interlock circuit is utilised to verify high-voltage component integrity. High-voltage interlock circuit is a circuit loop that passes through certain high-voltage components. High-voltage interlock circuit is used to determine if access to high-voltage components is being attempted. The opening of these high-voltage components causes high- voltage interlock circuit to open. The hybrid powertrain control module 2 monitors both the high- voltage interlock 5 V reference circuit voltage and the high-voltage interlock signal circuit voltage in order to detect circuit faults. When the hybrid powertrain control module 2 detects a loss of high-voltage interlock circuit voltage, the high-voltage contactors are commanded open.

Conditions for Running the DTC

•	The 12 V battery voltage is greater than 9 V.

•	The hybrid powertrain control module 2 is awake and communicating

Conditions for Setting the DTC

DTC P0641 and P0643

The hybrid powertrain control module 2 detects the main loop 5 V reference voltage is greater than 4.90 V.

DTC P0642

The hybrid powertrain control module 2 detects the main loop 5 V reference voltage is less than 2.63 V and the main loop signal is less than 1.08 V.

DTC P0651 and P0653

The hybrid powertrain control module 2 detects the charger loop 5 V reference voltage is greater than 4.90 V.

DTC P0652

The hybrid powertrain control module 2 detects the charger loop 5 V reference voltage is less than 2.63 V and the charger loop signal is less than 1.08 V.

Action Taken When the DTC Sets

DTCs P0641-P0643 and P0651-P0653 are type A DTCs.

Conditions for Clearing the DTC

DTCs P0641-P0643 and P0651-P0653 are type A DTCs.

Reference Information

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

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 .

Circuit/System Verification

Ignition ON, observe the scan tool High-Voltage System Interlock Circuit Status parameter. The reading should be PASS.

⇒	If the reading is UNKNOWN or FAIL, refer to P0641, P0642 and P0643.

Observe the scan tool Battery Charging System High-Voltage Interlock Circuit Status parameter. The reading should be PASS.

⇒	If the reading is UNKNOWN or FAIL, refer to P0651, P0652 and P0653.

Circuit/System Testing

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.

P0641, P0642, and P0643

Note: The main high-voltage interlock circuit is routed through several in-line connectors and modules.

Ignition OFF, disable high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling
Connect the 12 V battery.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal A at the S15 hybrid battery pack high voltage manual disconnect housing and earth.

⇒	If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.

⇒	If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.

Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for 8-10k Ω between the signal circuit terminal B and earth.

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

⇒	If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.

If all circuits test normal, test or replace the S15 hybrid battery pack high-voltage manual disconnect.