P0A12
High-Voltage Converter/Inverter
Pinpoint Test D: DTC P0A08, P0A09, P0A10, P0A11, P0A12 and P0A13
Normal Operation
The PCM controls the DC/DC enable hard-wired signal to switch the DC/DC converter on and off. The DC/DC converter provides feedback to the PCM using the hard-wired DC/DC fault signal. The DC/DC fault signal indicates to the PCM when the converter is non-operational or when a fault has occurred.
This pinpoint test is intended to diagnose the following:
- DC/DC converter
- High-voltage cable assembly
- PCM
- Electronically Controlled Continuously Variable Transmission (eCVT)
- DC/DC converter high-voltage wire harness
- Wiring, terminals or connectors
PINPOINT TEST D : DTCs P0A08, P0A09, P0A10, P0A11, P0A12 AND P0A13
WARNING: To prevent the risk of high-voltage shock, always follow precisely all warnings and service instructions, including instructions to depower the system. The high-voltage hybrid system utilizes approximately 300 volts DC, provided through high-voltage cables to its components and modules. The high-voltage cables and wiring are identified by orange harness tape or orange wire covering. All high-voltage components are marked with high-voltage warning labels with a high-voltage symbol. Failure to follow these instructions may result in serious personal injury or death.
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
NOTE: The 12-volt battery must be sufficiently charged before carrying out any DC/DC converter system diagnostics.
NOTE: The High Voltage Traction Battery (HVTB) must be at a minimum state of charge of 35% in order for the PCM to activate the DC/DC converter enable circuit in the KOER (Key ON Engine Running) position.
NOTE: DTC P0A09 set alone as a Continuous Memory Diagnostic Trouble Code (CMDTC) indicates an intermittent DC/DC fault circuit failure or that battery voltage has dropped below a preset limit.
D1 REVIEW THE PCM DTCs
- Review the DTCs retrieved and recorded during Inspection and Verification.
Is DTC P0A7C or any other MECS (Motor Electronics Cooling System) DTCs present in the PCM?
Yes
REFER to Computers and Control Systems Information to diagnose those DTCs first.
No
GO to D2.
D2 CHECK FOR FAULT REPEATABILITY
- Connect the scan tool.
- Ignition ON.
- Using the scan tool, clear the PCM DTCs.
- Ignition OFF.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- PCM.
Is DTC P0A08, P0A09, P0A10, P0A11, P0A12 or P0A13 present?
Yes
GO to D3.
No
GO to D24.
D3 CHECK FOR CURRENT DRAINS
- Ignition OFF.
- Carry out the Battery- Drain Test Component Tests and General Diagnostics. Refer to the Diagnosis and Testing subsystem in Battery.
Are any circuits causing excessive current drains?
Yes
REPAIR as necessary. TEST the system for normal operation.
No
GO to D4.
D4 CHECK THE HVTB (High Voltage Traction Battery) STATE OF CHARGE
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger- BCM-HVTB (Battery Control Module - High Voltage Traction Battery).
- Using the Battery Pack State of Change (BSOC) PID, verify that the HVTB (High Voltage Traction Battery) state of charge is greater than 35%.
Is the HVTB (High Voltage Traction Battery) state of charge greater than 35%?
Yes
GO to D5.
No
The HVTB (High Voltage Traction Battery) is under-charged. CARRY OUT a self-test of the BCM-HVTB (Battery Control Module - High Voltage Traction Battery). REFER to Hybrid Drive Systems to diagnose the HVTB (High Voltage Traction Battery).
D5 CHECK IF THE ENGINE WILL START
- START the vehicle (Ready Indicator Light ON).
- Test drive the vehicle over a short distance to verify that the engine starts.
Does the engine start?
Yes
GO to D8.
No
GO to D6.
D6 MONITOR THE TCM (Transmission Control Module) HIGH-VOLTAGE CONTACTOR (CONTACT) PID
- Ignition OFF.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger- TCM.
- Monitor the TCM (Transmission Control Module) CONTACT PID.
Does the PID indicate that the contactors are closed?
Yes
GO to D7.
No
The Battery Control Module - High Voltage Traction Battery (BCM-HVTB) is unable to close the contactors. CARRY OUT a Self Test of the BCM-HVTB (Battery Control Module - High Voltage Traction Battery). REFER to Hybrid Drive Systems to diagnose the high-voltage system.
D7 CHECK THE TRANSAXLE ASSEMBLY HIGH-VOLTAGE (HVBAT_V) PID
- Monitor the TCM (Transmission Control Module) HVBAT_V PID.
Is the voltage between 216 and 400 volts?
Yes
GO to D8.
No
GO to D25.
D8 VERIFY THE MECS (Motor Electronics Cooling System) COOLANT TEMPERATURE (MECT_V) PID
- Enter the following diagnostic mode on the scan tool: DataLogger- PCM.
- Monitor the PCM MECT_V PID.
Is the voltage greater than 1.2 volts?
Yes
GO to D9.
No
The MECS (Motor Electronics Cooling System) may be overheating. REFER to the appropriate pinpoint test for DTC P0A7C in Computers and Control Systems Information.
D9 CHECK THE POSITIVE 12-VOLT CABLE VOLTAGE DROP
- START the vehicle (Ready Indicator Light ON).
- With the headlights on high beam and the heater blower fan on high, measure the voltage drop between DC/DC converter C1457C, positive post and 12-volt battery C1100A, positive post.
Is the voltage drop less than 0.75 volt?
Yes
GO to D10.
No
REPAIR or INSTALL a new 12-volt battery cable assembly as necessary. TEST the system for normal operation.
D10 CHECK THE NEGATIVE 12-VOLT CABLE VOLTAGE DROP
- With the engine still running, and with the headlights on high beam and the heater blower fan on high, measure the voltage drop between DC/DC converter C1457B, negative post and DC/DC converter ground G105, ground bolt side.
Is the voltage drop less than 0.25 volt?
Yes
GO to D11.
No
REPAIR or INSTALL a new 12-volt battery cable assembly as necessary. TEST the system for normal operation.
D11 CHECK FOR AN OPEN IN THE DC/DC CONVERTER WIRING HARNESS
- Turn off the headlights and heater blower fan.
- Ignition OFF.
- Depower the HVTB (High Voltage Traction Battery) system. Refer to the general procedure in Hybrid Drive Systems.
- Disconnect: DC/DC Converter C1457D.
- Disconnect: TCM (Transmission Control Module) C1458E.
- Measure the resistance between DC/DC converter C1457D-(+), circuit HYT03 (OG), harness side, and TCM (Transmission Control Module) C1458E-(+), circuit HYT03 (OG), harness side.
- Measure the resistance between DC/DC converter C1457D-(-), circuit HYT04 (OG), harness side, and TCM (Transmission Control Module) C1458E-(-), circuit HYT04 (OG), harness side.
Are the resistances less than 5 ohms?
Yes
GO to D12.
No
INSTALL a new DC/DC converter wiring harness. REFER to Direct Current/Direct Current (DC/DC) Converter Wiring Harness . CLEAR the DTCs. REPEAT the self-test.
D12 CHECK THE DC/DC CONVERTER FOR AN OVER-CHARGING CONDITION
- Connect: DC/DC Converter C1457D.
- Connect: TCM (Transmission Control Module) C1458E.
- Disconnect: DC/DC Converter C1457A.
- Repower the HVTB (High Voltage Traction Battery) system. Refer to the general procedure in Hybrid Drive Systems.
- Ignition ON.
- Measure the battery voltage and record.
Is the voltage less than 16 volts?
Yes
GO to D13.
No
INSTALL a new DC/DC converter. REFER to Direct Current/Direct Current (DC/DC) Converter . CLEAR the DTCs. REPEAT the self-test.
D13 VERIFY CORRECT DC/DC CONVERTER OPERATION
- Ignition OFF.
- Measure the battery voltage and compare it to the value recorded in step D12.
Was the battery voltage at least 0.5 volts greater when the ignition was in the ON position?
Yes
If DTC P0A11, P0A12 or P0A13 was retrieved, GO to D14.
If DTC P0A08, P0A09 or P0A10 was retrieved, GO to D19.
No
INSTALL a new DC/DC converter. REFER to Direct Current/Direct Current (DC/DC) Converter . CLEAR the DTCs. REPEAT the self-test.
D14 CHECK THE DC/DC CONVERTER ENABLE CIRCUIT FOR AN OPEN
- Disconnect: PCM C175T.
- Measure the resistance between DC/DC converter C1457A-1, circuit CYD03 (BN/YE), harness side, and PCM C175T-12, circuit CYD03 (BN/YE), harness side.
Is the resistance less than 5 ohms?
Yes
GO to D15.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
D15 CHECK THE DC/DC CONVERTER ENABLE CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between DC/DC converter C1457A-1, circuit CYD03 (BN/YE), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to D16.
D16 CHECK THE DC/DC CONVERTER ENABLE CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between DC/DC converter C1457A-1, circuit CYD03 (BN/YE), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to D17.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
D17 CHECK FOR CORRECT DC/DC CONVERTER OPERATION
- Connect: PCM C175T.
- Ignition ON.
- Measure the battery voltage.
- While monitoring the measured battery voltage, momentarily connect a fused jumper wire between DC/DC converter C1457A-1, circuit CYD03 (BN/YE), component side and ground.
- While monitoring the measured battery voltage, disconnect the fused jumper wire between DC/DC converter C1457A-1, circuit CYD03 (BN/YE), component side and ground.
Does the battery voltage drop approximately 1 volt when the jumper wire is connected (disabling the DC/DC converter) and increase approximately 1 volt when the jumper wire is disconnected (enabling the DC/DC converter)?
Yes
GO to D18.
No
INSTALL a new DC/DC converter. REFER to Direct Current/Direct Current (DC/DC) Converter . CLEAR the DTCs. REPEAT the self-test.
D18 CHECK THE DC/DC CONVERTER USING THE PCM DC/DC CONVERTER ENABLE (DCE) PID
- Ignition OFF.
- Connect: DC/DC Converter C1457A.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger- PCM.
- Measure the battery voltage.
- While monitoring the measured battery voltage, command the PCM DCE active command on and off.
Does the battery voltage increase and decrease in accordance with the cycling of the active command?
Yes
CLEAR the DTCs. GO to D19.
No
GO to D26.
D19 CHECK THE DC/DC CONVERTER FAULT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: DC/DC Converter C1457A (if not previously disconnected).
- Disconnect: PCM C175B.
- Measure the resistance between DC/DC converter C1457A-6, circuit CYD04 (BU/OG), harness side, and PCM C175B-8, circuit CYD04 (BU/OG), harness side.
Is the resistance less than 5 ohms?
Yes
GO to D20.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
D20 CHECK THE DC/DC CONVERTER FAULT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between DC/DC converter C1457A-6, circuit CYD04 (BU/OG), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to D21.
D21 CHECK THE DC/DC CONVERTER FAULT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between DC/DC converter C1457A-6, circuit CYD04 (BU/OG), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to D22.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
D22 CHECK THE PCM FOR AN OPEN CIRCUIT
- Ignition OFF.
- Measure the resistance between PCM C175B-8, circuit CYD04 (BU/OG), component side and PCM C175B-67, circuit CBB29 (WH/VT), component side, and between PCM C175B-8, circuit CYD04 (BU/OG), component side and PCM C175B-68, circuit GD122 (BK), component side.
Are the resistances between 1,000 and 2,000 ohms?
Yes
GO to D23.
No
GO to D26.
D23 CHECK THE DC/DC CONVERTER FAULT CIRCUIT FOR A SHORT IN THE PCM
- Connect: PCM C175B.
- Ignition ON.
- Measure the voltage between DC/DC converter C1457A-6, circuit CYD04 (BU/OG), harness side and ground.
Is the voltage less than 10.5 volts?
Yes
GO to D26.
No
INSTALL a new DC/DC converter. REFER to Direct Current/Direct Current (DC/DC) Converter . CLEAR the DTCs. REPEAT the self-test.
D24 CHECK THE DC/DC CONVERTER CIRCUITS FOR AN INTERMITTENT CONCERN
- Ignition OFF.
- Connect: DC/DC Converter C1457A (if previously disconnected).
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger- PCM.
- While monitoring the PCM DCE and PCM DC/DC converter status (DCE_F) PIDs, carefully wiggle all accessible wiring and connectors associated with the circuit and monitor the PIDs for a change in state.
Do the PIDs indicate a concern while wiggling the harness or connectors?
Yes
REPAIR the affected circuit(s).
Refer to Wiring Diagram Set 12 for schematic and connector information Electrical Diagrams.
CLEAR the DTCs. REPEAT the self-test.
No
The concern cannot be duplicated at this time. VERIFY the 12-volt battery is sufficiently charged. CLEAR the DTCs. REPEAT the self-test.
D25 CHECK THE HIGH-VOLTAGE CABLE FOR AN OPEN
- Ignition OFF.
- Depower the HVTB (High Voltage Traction Battery) system. Refer to the general procedure in Hybrid Drive Systems.
- Disconnect: TCM (Transmission Control Module) C1458D.
- Disconnect: BCM-HVTB (Battery Control Module - High Voltage Traction Battery) C4227B.
- Measure the resistance as shown in the table below:
TCM (Transmission Control Module) Circuit BCM-HVTB (Battery Control Module - High Voltage Traction Battery) C1458D-(+) HYT03 (OG) C4227B-(+) C1458D-(-) HYT04 (OG) C4227B-(-)
Is the resistance less than 5 ohms?
Yes
INSTALL a new eCVT (Electronically Controlled Continuously Variable Transmission). CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new high-voltage cable assembly. CLEAR the DTCs. REPEAT the self-test.
D26 CHECK THE PCM FOR CORRECT OPERATION
- Ignition OFF. (if not previously turned to the OFF position)
- Disconnect: PCM C175B.
- Disconnect: DC/DC Converter C1457A.
- Check the PCM and DC/DC converter connectors for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: DC/DC Converter C1457A.
- Connect: PCM C175B.
- Verify that each connector is correctly seated.
- Carry out the PCM self-test and verify that the concern is still present.
Is the concern still present?
Yes
INSTALL a new PCM. REPEAT the self-test.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.