Test Procedure

HH1: DIAGNOSTIC TROUBLE CODES (DTCS) P0A08, P0A10, P0A11, P0A12 AND P0A13: CHECK FOR SELF-TEST DTCS
NOTE: Repair any DTCs related to the motor electronics coolant temperature (MECT) or contactors before entering this pinpoint test.

NOTE: The 12-volt battery must be sufficiently charged for DC/DC diagnostics.

NOTE: The traction battery (TB) must be at a minimum of 35% state of charge for the PCM to activate the DCE circuit with the KOER position.
- Are DTCs P0A08, P0A10, P0A11, P0A12, P0A13 present during PCM or transaxle control module (TCM) self-test?
- Yes: For KOEO and KOER DTC P0A08, GO to HH2.
  For KOEO and KOER DTC P0A10, GO to HH17.
  
  For KOEO and KOER DTCs P0A11, P0A12 and P0A13, GO to HH11.
  
  For continuous memory DTCs P0A08, P0A10, P0A11, P0A12 and P0A13, GO to HH23.
- No: Unable to duplicate or identify the concern at this time.
  RETURN to SYMPTOM CHARTS for further direction.
HH2: KOEO AND KOER DTC P0A08: CHECK IF THE VEHICLE ENGINE STARTS
- Does the engine start?
- Yes: GO to HH5.
- No: GO to HH3.
HH3: CHECK THE HIGH VOLTAGE BATTERY CONTACTOR STATUS
- Key ON, engine OFF.
- Access the TCM and monitor the CONTACT PID.
- Does the PID indicate the contactors are closed?
- Yes: GO to HH4.
- No: Unable to close the traction battery contactors.
  REFER to the HIGH-VOLTAGE TRACTION BATTERY -- HYBRID .
HH4: CHECK THE TRANSAXLE ASSEMBLY HIGH VOLTAGE
- Access the TCM and monitor the HVBAT_V PID.
- Is the voltage between 216 - 400 V?
- Yes: GO to HH5.
- No: DIAGNOSE the high voltage supply concern.
  GO to TS: TRACTION MOTOR AND GENERATOR MOTOR HIGH VOLTAGE INVERTER PERFORMANCE .
HH5: VERIFY THE MECT
NOTE: High MECT limits DC/DC converter performance.
- Access the PCM and monitor the MECT_V PID.
- Reference the voltage transfer function table in Pinpoint Test DN.
- Is the temperature less than 65°C (149°F)?
- Yes: GO to HH6 .
- No: DIAGNOSE the MECT sensor concern.
  GO to DN: MOTOR ELECTRONICS COOLANT TEMPERATURE (MECT) SENSOR .
HH6: VERIFY THE LOW VOLTAGE BATTERY CONNECTIONS ON THE DC/DC CONVERTER
- Key in OFF position.
- Check the low voltage battery connections on the DC/DC converter for corrosion and the proper connection.
- Measure the voltage at the DC/DC converter low voltage battery connections.
- Does the voltage read +/- 0.1 volt of 12-volt battery voltage?
- Yes: GO to HH7 .
- No: REPAIR as necessary.
  CLEAR the DTCs. REPEAT the self-test.

HH7: CHECK THE HIGH VOLTAGE POSITIVE CABLE FOR AN OPEN

Key in OFF position.
Transaxle Assembly-DDHV connector disconnected.
DDC-HV connector disconnected.

Measure the resistance between:

(+) Transaxle Assembly-DDHV Connector, Harness Side	(-) DDC-HV Connector, Harness Side
HVP - Pin (+)	HVP - Pin (+)

Is the resistance less than 5 ohms?

Yes: GO to HH8 .
No: INSTALL a new high voltage cable from the transaxle assembly to the DC/DC converter. REFER to the HIGH-VOLTAGE CONVERTER/INVERTER -- HYBRID .

HH8: CHECK THE HIGH VOLTAGE NEGATIVE CABLE FOR AN OPEN

Measure the resistance between:

(+) Transaxle Assembly-DDHV Connector, Harness Side	(-) DDC-HV Connector, Harness Side
HVN - Pin (-)	HVN - Pin (-)

Is the resistance less than 5 ohms?

Yes: GO to HH9 .
No: INSTALL a new high voltage cable from the transaxle assembly to the DC/DC converter. REFER to the HIGH-VOLTAGE CONVERTER/INVERTER -- HYBRID .

HH9: CHECK FOR THE DC/DC CONVERTER OVERCHARGING THE LOW VOLTAGE BATTERY

NOTE: Disconnecting the DCE circuit activates the DC/DC converter with the key in the ON position.

DDC-HV connector connected.
Transaxle Assembly-DDHV connector connected.
Key ON, engine OFF.
DDC-A connector disconnected.

Measure the voltage between:

(+) Vehicle Battery	(-) Vehicle Battery
Positive terminal	Negative terminal

Is VBAT less than 16 volts when the DC/DC converter is enabled?

Yes: GO to HH10 .
No: INSTALL a new DC/DC converter. REFER to the HIGH-VOLTAGE CONVERTER/INVERTER -- HYBRID .

HH10: CHECK FOR DTC P0A11, P0A12, OR P0A13 DC/DC ENABLE CIRCUIT CONCERNS
- Are DTCs P0A11, P0A12, or P0A13 present?
- Yes: GO to HH11 .
- No: GO to HH18.

HH11: CHECK THE FUNCTIONALITY OF DC/DC CONVERTER

NOTE: Disconnecting the DCE circuit activates the DC/DC converter with the key in the ON position.

Key in OFF position.
DDC-A connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) Vehicle Battery	(-) Vehicle Battery
Positive terminal	Negative terminal

Record the 12-volt battery voltage.
Key in OFF position.
Record the 12-volt battery voltage.
Does the 12-volt battery voltage increase when the key is in the ON position?

Yes: GO to HH12 .
No: INSTALL a new DC/DC converter. REFER to the HIGH-VOLTAGE CONVERTER/INVERTER -- HYBRID .

HH12: CHECK THE DCE CIRCUIT FOR AN OPEN IN THE HARNESS

PCM connector disconnected.

Measure the resistance between:

(+) DDC-A Connector, Harness Side	(-) PCM Connector, Harness Side
DCE - 3259 - Pin 1	DCE - Pin T44

Is the resistance less than 5 ohms?

Yes: GO to HH13 .
No: REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test.

HH13: CHECK THE DCE CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

Key ON, engine OFF.

Measure the voltage between:

(+) PCM Connector, Harness Side	(-) Vehicle Battery
DCE - Pin T44	Negative terminal

Is the voltage less than 1 V?

Yes: GO to HH14 .
No: REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test.

HH14: CHECK THE DCE CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

Key in OFF position.

Measure the resistance between:

(+) PCM Connector, Harness Side	(-) Vehicle Battery
DCE - Pin T44	Negative terminal

Is the resistance greater than 10K ohms?

Yes: GO to HH15 .
No: REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test.

HH15: CHECK THE FUNCTIONALITY OF THE DCE CIRCUIT

Key ON, engine OFF.

Connect a 5 amp fused jumper wire between the following:

Point A DDC-A Connector, Component Side	Point B Vehicle Battery
DCE - 3259 - Pin 1	Negative terminal

Measure the voltage between:

(+) Vehicle Battery	(-) Vehicle Battery
Positive terminal	Negative terminal

Does VBAT drop approximately 1 volt when the jumper wire is installed (forcing the DC/DC to disable), and increase approximately 1 volt when the jumper wire is removed (forcing the DC/DC to enable)?

Yes: GO to HH16.
No: INSTALL a new DC/DC converter. REFER to the HIGH-VOLTAGE CONVERTER/INVERTER -- HYBRID .

HH16: CHECK THE FUNCTIONALITY OF THE PCM DCE CIRCUIT

Key in OFF position.
DDC-A connector connected.
PCM connector connected.

Measure the voltage between:

(+) Vehicle Battery	(-) Vehicle Battery
Positive terminal	Negative terminal

Key ON, engine OFF.
Access the PCM and control the DCE PID.
Enable and disable the DCE circuit.
Does VBAT indicate the DC/DC converter is cycling on and off with output state control?

Yes: CLEAR the DTCs.
GO to HH17.
No: GO to HH24.

HH17: KOEO AND KOER DTC P0A10: CHECK FOR DTC P0A11, P0A12, OR P0A13 DC/DC ENABLE CIRCUIT CONCERNS
- Are any of the following on-demand DTCs present: P0A11, P0A12, or P0A13?
- Yes: GO to HH11.
- No: GO to HH18.

HH18: CHECK THE DCF CIRCUIT FOR AN OPEN IN THE HARNESS

Key in OFF position.
DDC-A connector disconnected.
PCM connector disconnected.

Measure the resistance between:

(+) DDC-A Connector, Harness Side	(-) PCM Connector, Harness Side
DCF - 3989 - Pin 6	DCF - Pin T34

Is the resistance less than 5 ohms?

Yes: GO to HH19.
No: REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test.

HH19: CHECK THE DCF CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

Key ON, engine OFF.

Measure the voltage between:

(+) PCM Connector, Harness Side	(-) Vehicle Battery
DCF - Pin T34	Negative terminal

Is the voltage less than 1 V?

Yes: GO to HH20.
No: REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test.

HH20: CHECK THE DCF CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

Key in OFF position.

Measure the resistance between:

(+) PCM Connector, Harness Side	(-) Vehicle Battery
DCF - Pin T34	Negative terminal

Is the resistance greater than 10K ohms?

Yes: GO to HH21.
No: REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test.

HH21: CHECK THE DCF CIRCUIT FOR AN OPEN IN THE PCM

Key in OFF position.

Measure the resistance between:

(+) PCM Connector, Component Side	(-) PCM Connector, Component Side
VPWR - Pin B35, B36	DCF - Pin T34

Is the resistance between 1K - 2K ohms?

Yes: GO to HH22.
No: GO to HH24.

HH22: CHECK THE DCF CIRCUIT FOR A SHORT TO GND IN THE PCM

DDC-A connector connected.
PCM connector connected.
Disconnect the DCF pin from the DDC-A connector.
Key ON, engine OFF.

Measure the voltage between:

(+) DDC-A Connector, Harness Side	(-)
DCF - 3989 - Pin 6	Ground

Is the voltage less than 10.5 V?

Yes: GO to HH24.
No: INSTALL a new DC/DC converter. REFER to the HIGH-VOLTAGE CONVERTER/INVERTER -- HYBRID .

HH23: CHECK THE DC TO DC CONVERTER CIRCUITS FOR AN INTERMITTENT CONCERN
NOTE: The continuous memory PCM DTC P0A09 alone indicates the intermittent DC/DC fault (DCF) circuit failure, or the 12 V bus voltage dropped below the calibrated threshold.
- Key ON, engine OFF.
- Access the PCM and monitor the DCE PID.
- Access the PCM and monitor the DCE_F PID.
- Carefully wiggle all accessible wiring and connectors associated with the circuit and look for a change in the PID state.
- Does the PID indicate a concern while wiggling the harness or connectors?
- Yes: REPAIR as necessary.
  CLEAR the DTCs. REPEAT the self-test.
- No: Unable to duplicate or identify the concern at this time.
  Make sure the 12-volt battery is sufficiently charged.
HH24: CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
  - pushed out pins
  - corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new PCM.
  REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .
- No: The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.