Pinpoint Test At: P0C79
- NOTE: The Secondary Inverter System Controller (S-ISC) is referred to as the SOBDMB (Secondary On-Board Diagnostic Control Module B) in the scan tool.
Normal Operation and Fault Conditions
REFER to: Front Electric Drive Assembly - System Operation and Component Description .
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition SOBDMB P0C79:00 Drive Motor "A" Inverter Voltage Too High: No Sub Type Information This DTC sets when an overvoltage event has occurred in the module. Possible Sources
- Other Secondary Inverter System Controller (S-ISC) DTCs
- Loose high voltage cables
- Service disconnect not connected
- Wiring, terminals or connectors
- AT1 CHECK THE BECM (BATTERY ENERGY CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, run the BECM self-test.
Are there any BECMDTCs?
Yes DIAGNOSE and REPAIR any BECMDTCs. REFER to: High Voltage Battery, Mounting and Cables . No GO to AT2 - AT2 CHECK THE SECONDARY INVERTER SYSTEM CONTROLLER (S-ISC) CONTINUOUS MEMORY DIAGNOSTIC CODES (CMDTCS)
- Using a diagnostic scan tool, check for CMDTCs
Was P0C79 the only CMDTC stored in the Secondary Inverter System Controller (S-ISC)?
Yes GO to AT3 No DIAGNOSE and REPAIR any Secondary Inverter System Controller (S-ISC) DTCs. REFER to Diagnostic Trouble Code (DTC) Chart . - AT3 VERIFY CONCERN IS PRESENTNOTE: Clearing the Secondary Inverter System Controller (S-ISC) Diagnostic Trouble Codes (DTCs) will erase any Secondary Inverter System Controller (S-ISC) recorded freeze frame data. Make sure to record any Secondary Inverter System Controller (S-ISC) freeze frame information before proceeding any further. Refer to the scan tool instruction manual for freeze frame Parameter Identification (PID) menu.
- Ignition ON.
- CLEAR the Secondary Inverter System Controller (S-ISC) DTCs.
- CARRY out the Secondary Inverter System Controller (S-ISC) self-test.
Is DTC P0C79 present?
Yes GO to AT4 No The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - AT4 CHECK THE HIGH VOLTAGE CABLES FOR AN INTERMITTENT CONCERN
- Ignition OFF.
- De-energize the high voltage system. REFER to: High Voltage System De-energizing .
- Disconnect and inspect all the High Voltage Battery Junction Box connectors.
- Disconnect and inspect all the Secondary Inverter System Controller (S-ISC) connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect the High Voltage Battery Junction Box connectors. Make sure they seat and latch correctly.
- Reconnect the Secondary Inverter System Controller (S-ISC) connectors. Make sure they seat and latch correctly.
- Re-energize the high voltage system. REFER to: High Voltage System De-energizing .
- Ignition ON.
- Access the SOBDMB and monitor the GEN_INV_V (V) PID
- Carefully wiggle all accessible wiring and connectors associated with the High Voltage Cable from the Secondary Inverter System Controller (S-ISC) to the Traction Battery, and look for a change in the PID state.
Is a concern present during the wiggle test?
Yes REPAIR as necessary. No The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.