Pinpoint Test AJ : P0C79

Normal Operation and Fault Conditions

REFER to: Electric Powertrain Control - System Operation and Component Description .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
SOBDMC P0C79:00	Drive Motor "A" Inverter Voltage Too High: No Sub Type Information	This DTC sets when a overvoltage event has occurred in the module.

Possible Sources

Loose high voltage cables
Service disconnect not connected
Wiring, terminals or connectors

AJ1 CHECK THE BECM (BATTERY ENERGY CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)

Using a diagnostic scan tool, run the BECM and Inverter System Controller (ISC) self-tests.

Are there any BECM or Inverter System Controller (ISC) DTCs?

Yes	DIAGNOSE and REPAIR any BECM or Inverter System Controller (ISC) DTCs. For. REFER to: High Voltage Battery, Mounting and Cables . For Inverter System Controller (ISC) DTCs. REFER to the Diagnostic Trouble Code (DTC) Chart .

GO to AJ2

AJ2 VISUAL INSPECTION OF THE HIGH VOLTAGE SYSTEM
- Ignition OFF.
- Depower the high voltage battery. REFER to: High Voltage System De-energizing .
- Visually inspect all the high voltage cables.
- Make sure all the high voltage connectors are correctly and securely connected.
- Examine all the high voltage cables and connectors for damaged, burned or overheated insulation and loose or broken connections.
Is a concern present?

Yes REPAIR as necessary. CLEAR the DTCs and REPEAT the self-test.

No GO to AJ3

AJ3 VERIFY THE HIGH VOLTAGE TRACTION BATTERY STATE OF CHARGE

Ignition ON.

Access the SOBDMC and monitor the HVBAT_V (V) PID

Is the voltage greater than 250 volts?

Yes

GO to AJ4

No	CHARGE the high voltage traction battery. REFER to: High Voltage Battery Charging - Hybrid Electric Vehicle (HEV) . CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

AJ4 VERIFY CONCERN IS PRESENT

NOTE: Clearing the Inverter System Controller (ISC) Diagnostic Trouble Codes (DTCs) erases any Inverter System Controller (ISC) recorded freeze frame data. Record any Inverter System Controller (ISC) freeze frame information before proceeding any further. Refer to the scan tool instruction manual for freeze frame Parameter Identification (PID) menu.

Install the high voltage traction battery service disconnect plug.

Ignition ON.

Clear the Inverter System Controller (ISC) DTCs.

Carry out the Inverter System Controller (ISC) self-test.

Is DTC P0C79 present?

Yes

GO to AJ5

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, the TRID block was not programmed correctly or was erased.

AJ5 CHECK THE HIGH VOLTAGE CABLES FOR AN INTERMITTENT CONCERN

Ignition OFF.

Disconnect and inspect all the High Voltage BJB connectors.

Disconnect and inspect all the Inverter System Controller (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 BJB connectors. Make sure they seat and latch correctly.

Reconnect the Inverter System Controller (ISC) connectors. Make sure they seat and latch correctly.

Install the high voltage traction battery service disconnect plug.

Ignition ON.

Access the SOBDMC and monitor the GEN_INV_V (V) PID.

Carefully wiggle all accessible wiring and connectors associated with the high voltage cable from the Inverter System Controller (ISC) to the traction battery, and look for a change in the PID state.

Is a concern present during the wiggle or drive cycle 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.