Hybrid/ev Control System Buick LaCrosse II

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Exterior Lighting Systems Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/exterior-lights/#lighting-system-description-and-operation)
«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

DTC P057C and P057D

Verify that DTC P0562 or P0563 is not set. If DTC P0562 or P0563 is set, refer to «DTC B1325, B1330, B1420, B1424, B1517, C0800, C0895, C0899, C0900, C12E1, C12E2, P0560, P0562, or P0563»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-hybrid-hp6) for Hybrid (HP6).
Ignition OFF, disconnect the harness connector at the B22 brake pedal position sensor.
Ignition ON, verify that a test lamp illuminates between B+ and the low reference circuit terminal 5. If the test lamp does not illuminate, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K59 starter generator control module.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 6 and ground. 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 K59 starter generator control module. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K59 starter generator control module.
Test for less than 0.3 V between the signal circuit terminal 4 and ground. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K59 starter generator control module.
Test for 4.8-5.2 V between the 5 V reference circuit terminal 6 and the signal circuit terminal 4. If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K59 starter generator control module.
Ignition OFF, disconnect the X2 harness connector at the K59 starter generator control module.
Test for infinite resistance between the signal circuit terminal 4 and ground. If less than the specified range, test the signal circuit for a short to ground.
If all circuits test normal, replace the B22 brake pedal position sensor.

DTC P057B

Operate the vehicle within the Conditions for Running and Setting the DTC and verify the DTC does not reset.

If DTC P057B resets as current, replace the B22 brake pedal position sensor.

DTC P057E

Replace the brake pedal position sensor.
Perform the brake pedal position sensor calibration procedure. Refer to «Brake Pedal Position Sensor Calibration»(/buick/lacrosse/ii-2009-2013/remont/exterior-lights/#lighting-system-repair-instructions__brake-pedal-position-sensor-calibration) .
Operate the vehicle within the Conditions for Running and Setting the DTC and verify the DTC does not reset. If DTC P057E resets as current, replace the K59 starter generator control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

«Brake Pedal Position Sensor Calibration»(/buick/lacrosse/ii-2009-2013/remont/exterior-lights/#lighting-system-repair-instructions__brake-pedal-position-sensor-calibration)
«Brake Pedal Position Sensor Replacement»(/buick/lacrosse/ii-2009-2013/remont/exterior-lights/#lighting-system-repair-instructions__brake-pedal-position-sensor-replacement)
«Control Module References»(/buick/lacrosse/ii-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The ignition is ON.
The system voltage is greater than 9.5V.

The control module has detected an internal malfunction.

P0602

A service module has been installed but not yet programmed.

Action Taken When the DTC Sets

DTCs P0601-P0604, P0606, P061B, and P062F are Type A DTCs.
DTC P262B is a Type B DTC.

P0601, P0602, P0604, P0606, P061B, and P262B

The hybrid powertrain control module requests the high voltage contactor relay open.

DTCs P0601-P0604, P0606, P061B, and P062F are Type A DTCs.
DTC P262B is a Type B DTC.

DTC P0606 may cause DTCs U0073, U0074, U0293, U1817 to set.

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Circuit/System Verification

Verify that DTC P0562 is not set. If DTC is set, refer to «DTC B1325, B1330, B1420, B1424, B1517, C0800, C0895, C0899, C0900, C12E1, C12E2, P0560, P0562, or P0563»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-hybrid-hp6) for Engine Electrical - Hybrid (HP6).
If the DTC is not set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The hybrid powertrain control module has three internal 5 V reference circuits. Each internal reference circuit provides a 5 V reference for one or more sensors. A short to ground or short to voltage on one external 5 V reference circuit can affect all components connected to the same internal 5 V reference circuit.

Ignition is on.
Ignition voltage is greater than 10 V.

The hybrid powertrain control module detects a voltage out of range on the 5 V reference 3 circuit for greater than 5 seconds.

DTC P0697 is a Type B DTC.

The 5 V reference 3 circuit provides 5 V to internal circuitry contained in the generator control module.

Schematic Reference

«Hybrid Controls Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Energy Storage Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

If the DTC is set, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The hybrid powertrain control module monitors a state of health message that the ECM transmits to verify the ECM is functioning properly.

Ignition is On.
The system voltage is greater than 9.5 V.

The hybrid powertrain control module does not detect a valid state of health message from the ECM.

DTC P06AF is a Type A DTC.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Verify that ECM DTC P0606 is not set. If the DTC is set, Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Ignition OFF, disconnect the K59 starter generator control module X3 connector and the K20 ECM X1 connector.
Test for less than 1 ohms between the serial data circuits listed below: K59 starter generator control module X3 connector terminal 16 and K20 ECM X1 connector terminal 36 K59 starter generator control module X3 connector terminal 17 and K20 ECM X1 connector terminal 37 If greater than the specified range, test the serial data circuit for an open/high resistance condition. If the circuit tests normal, replace the K20 ECM.
If the DTC resets, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for ECM or Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The motor control modules are part of the generator control module. The drive motor control module uses an internal 15 V reference power supply in order to operate the drive motor sensors and processor. This fault is handled inside the generator control module and no external circuits are involved.

The drive motor control module is awake.

P06B1

The reference voltage is less than 9.7 V for 1 second.

P06B2

The reference voltage is greater than 18 V for 1 second.

DTCs P06B1 and P06B2 are Type B DTCs.

This DTC may set due to low or high 12 V system voltage.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Verify P0562 or P0563 is not set.

If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
If DTC P06B1 or P06B2 is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This fault is handled inside the drive motor control module and no external circuits are involved.

The ignition is ON.
Ignition voltage is greater than 9.5 V.

The control module has detected an internal malfunction.

DTCs P0A1B, P1A50, P1A51, P1ADC and P1EB6 are Type A DTCs.

P0A1B, P1A50, and P1A51

The hybrid powertrain control module opens the high voltage contactor relay.

DTCs P0A1B, P1A50, P1A51, P1ADC and P1EB6 are Type A DTCs.

DTC P0A1B may cause DTCs U0073, U0074, U0293, U1817 to set.

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

If the DTC is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Motor Temperature Sensor Signal	P0A2C	P0A2D	P0A2D	P0A2B
Motor Temperature Sensor Low Reference		P0A2D		P0A2B

Typical Scan Tool Data

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON Parameter Normal Range: -39°C (-38°F) to 214°C (417°F)
Motor Temperature Signal	215°C (419°F)	40°C (-40°F)	Sensor Damage Possible
Motor Temperature Sensor Low Reference		40°C (-40°F)

Drive Motor Temperature

The motor temperature sensor is a non-serviceable part of the starter generator assembly, often referred to as the drive motor assembly. The motor temperature sensor is a thermistor, or a resistor that changes value when the temperature changes. The motor temperature sensor is located in the stator. The sensor has a negative-temperature coefficient. This means that as the temperature increases, the resistance decreases, and as the temperature decreases, the resistance increases. The motor control module supplies a 5 V reference signal to the sensor and measures the voltage drop in the circuit. When the motor is cold, the sensor resistance is high. As the motor temperature increases, the resistance of the sensor decreases, which lowers the signal voltage.

P0A2B

DTC P0A2B, P0A2C, P0A2D, P0A2F, P0AEE, P0AEF, P0AF0, P1A71, P1A72, P1A73, P1A90, P1A91, P1A92, P0C11, or P262B is not set.
The Engine off time is greater than 8 hours.
The Ignition is ON.
Ignition voltage is between 9-16V.

P0A2C

The drive motor control module and the hybrid powertrain control module are awake.

P0A2D

Vehicle has been driven with starter generator torque greater than 10 N.m (89 lb in) for at least 90 seconds.

P0A2B

The Motor temperature is more than 25°C (45°F) greater than the average of the 14 volt power module temperature sensors and the power inverter module temperature.

P0A2C

Motor temperature sensor signal is greater than 215°C (419°F) for 1 second.

P0A2D

Motor temperature sensor signal is less than -40°C (-40°F) for 1 second after a warm up condition when drive motor generator torque is greater than 10 N.m (89 lb in) for 90 seconds.

DTCs P0A2B-P0A2D are Type B DTCs.

The motor temperature sensor can be damaged by excessive electric current. Test the sensor for an open condition whenever a short to voltage condition is observed.

Schematic Reference

«Hybrid Controls Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Energy Storage Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

P0A2B-P0A2D

Allow the vehicle to cool to ambient temperature by leaving the ignition OFF for at least 8 hours.
Ignition ON, observe the motor temperature scan tool parameters. The temperature parameter should be within 25°C (45°F) of ambient temperature.

Ignition OFF, disconnect the starter generator X1 harness connector from the A15 starter generator.
Ignition ON, test the harness side for less than 12 ohms between the low reference circuit terminal 7 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K59 starter generator control module.
Ignition ON, verify the scan tool motor temperature sensor parameter is -40°C (-40°F). If more than the specified value, test the motor temperature sensor signal circuit for a short to ground. If the circuit tests normal, replace the K59 starter generator control module.
Install a 3-amp fused jumper wire between the signal circuit X1 terminal 8 and the low reference circuit X1 terminal 7 at the A15 starter generator. Verify the scan tool motor temperature sensor parameter is greater than 214°C (417°F): NOTE: If a short to voltage is found, test the motor temperature sensor for an open circuit or physical damage. If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K59 starter generator control module.
Ignition OFF, measure and record the resistance between the sensor signal and low reference terminals. Compare the actual sensor and circuit resistance to the expected sensor resistance. Refer to «Temperature Versus Resistance»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__temperature-versus-resistance) . If the resistance is not near the expected value, replace the A15 starter generator.

Perform the Diagnostic Repair Verification after completing the repair.

«Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement) for Drive Motor replacement
«Control Module References»(/buick/lacrosse/ii-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The starter generator is also referred to as the drive motor. The drive motor temperature sensor is a variable resistor that measures the temperature of the drive motor stator windings. The hybrid powertrain control module supplies 5 V to the signal circuit and a ground for the low reference circuit. The drive motor temperature sensor resistance changes with drive motor coolant temperature. As the temperature decreases, the sensor resistance increases. As the temperature increases, the sensor resistance decreases. The hybrid powertrain control module monitors the drive motor temperature sensor to determine the temperature of the drive motor.

DTC P0A2B, P0A2C, and P0A2D is not set.
The drive motor control module and hybrid powertrain control module are awake.

The motor temperature sensor is greater than 165°C (329°F) for 5 seconds.

DTC P0A2F is a Type B DTC.
The hybrid powertrain control module system starts to reduce the maximum torque beginning at 155°C (311°F) down to 0 N.m as the drive motor stator temperature approaches 165°C (329°F).

DTC P0A2F is a Type B DTC.

Ask about the customer's driving habits, trailer towing, etc.
Ensure the engine cooling system is functioning normally.
Ensure the starter generator cooling system is functioning normally.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Check the cooling system for the correct amount of coolant. Refer to «Cooling System Draining and Filling (Static Fill)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) , «Cooling System Draining and Filling (GE 47716)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-ge) .
Verify that DTC P0A2C is not set. If DTC P0A2C is set, Refer to «DTC P0A2B-P0A2D»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system) .
Ignition ON, observe the scan tool motor temperature parameter. The reading should be less than 165°C (329°F). If greater than the specified value, replace the starter generator assembly.

Perform the Diagnostic Repair Verification after completing the repair.

Starter Generator Replacement for Drive Motor replacement

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Resolver Signal 1/3 Circuit	P0C5C, P0A3F, P0A40, P1B03	P1B03, P0A3F	P0C53, P0A3F	P1B03, P0A40
Resolver Signal 2/4 Circuit	P0C52, P0A3F, P0A40, P1B03	P1B03, P0A3F	P0C5D, P0A3F	P1B03, P0A40
Resolver Motor Positive/Negative Circuit	P0A3F, P0A40, P1B03	P0A3F	P0A3F	P1B03, P0A40

The generator control module monitors the angular position, speed and direction of the starter generator rotor based upon the signals of the resolver-type motor position sensor. The position sensor contains a drive coil, two driven coils, and an irregular shaped metallic rotor. The metallic rotor is mechanically attached to the shaft of the starter generator.

At ignition ON, an ac voltage, 10 kHz excitation signal is output to the drive coil. The drive coil excitation signal creates a magnetic field surrounding the two driven coils and the irregular shaped rotor. The generator control module then monitors the two driven coil circuits for a return signal. The position of the irregular metallic rotor causes the magnetically-induced return signals of the driven coils to vary in size and shape. A comparison of the two driven coils signals allows the generator control module to determine the exact position, speed and direction of the starter generator rotor. The position sensor is a non-serviceable part of the starter generator.

Ignition voltage is greater than 9.5V.
The drive motor control module and hybrid powertrain control module are awake.

P0A3F

Sin or Cos signal is less than 2.3V.

P0A40

Sin or Cos signal is greater than 4V.

P0C52

Drive Motor Position Sensor Circuit 1 reference voltage is less than 0.5 V.

P0C53

Drive Motor Position Sensor Circuit 1 reference voltage is greater than 4.5 V.

P0C5C

Drive Motor Position Sensor Circuit 2 reference voltage is less than 0.5 V.

P0C5D

Drive Motor Position Sensor Circuit 2 reference voltage is greater than 4.5 V.

P1B03

The generator control module tracking error is greater than 5 degrees.

DTCs P0A3F, P0A40, P0C52, P0C53, P0C5C, P0C5D, and P1B03 are Type B DTCs.
Starter generator operation is disabled.
Autostop operation is disabled.
Autostart operation is disabled.
APM remains active until hybrid battery power is depleted, or APM power limits are exceeded, after which the high voltage contactor's relay is opened.

DTCs P0A3F, P0A40, P0C52, P0C53, P0C5C, P0C5D, and P1B03 are Type B DTCs.

The starter generator position sensor circuits operate at very low current. These circuits are susceptible to moisture intrusion, coolant contamination, corrosion, and terminal damage. Extreme care must be taken when removing the starter generator, probing terminals and manipulating harnesses. Poor terminal connections can result in intermittent operation.
If the customer comments that the problem occurs only during moist environmental conditions: rain, snow, vehicle wash, etc., inspect the sensor wiring and seals for signs of water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure: Spray the suspected area with a 5 percent saltwater solution. To create a 5 percent saltwater solution, add 2 teaspoons (12 g) of salt to 8 fl oz (237 ml) of water and wait 10 minutes. Test drive the vehicle at various speeds over various road surfaces such as bumps and turns. Rinse the area thoroughly when completed.
The sensor circuit loops are a twisted pair with each pair covered in a grounded foil shield.
The starter generator position sensor harness circuits are shielded. Improperly grounded shield circuits may cause inaccurate sensor signals.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Connector End View Reference

«COMPONENT CONNECTOR END VIEWS - INDEX»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#wiring-systems-and-power-management-component-connector-end-views-index)
«Inline Harness Connector End Views»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#wiring-systems-and-power-management-inline-harness-connector-end-views)

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition OFF, disconnect the X1 harness connector at the A15 starter generator.
Ignition ON, test for 1.7-3.2 V between the harness terminals listed below and ground: Terminal 1 Terminal 2 Terminal 5 Terminal 6 If not within the specified range Test the signal circuits for a short to voltage, short to ground or an open/high resistance. If all circuits test normal replace the K59 starter generator control module. If the test passed
Ignition ON, test for 6.5-8.5 V between the harness terminals listed below and ground: Terminal 3 Terminal 4 If not within the specified range Test the signal circuits for a short to voltage, short to ground or an open/high resistance. If all circuits test normal replace the K59 starter generator control module. If the test passed
Test the harness terminals list below for a short between each twisted pair and the drain wire: Terminals 1, 5, and 2 Terminals 3, 4, and 13 Terminals 6, 2, and 1 If all circuits test normal Replace the K59 starter generator control module.

Component Testing

Ignition OFF, disconnect the X1 harness connector at the A15 starter generator.
At the A15 starter generator, test for 10-35 ohms between the A15 starter generator AC terminal 3 and the AC terminal 4. If not within the specified range Replace the A15 starter generator. If the test passed
Test for 30-60 ohms between the signal terminal 1 and the signal terminal 5. If not within the specified range Replace the A15 starter generator. If the test passed
Test for 30-60 ohms between the signal terminal 2 and the signal terminal 6. If not within the specified range Replace the A15 starter generator. If the test passed
Test for greater than 10, 000 ohms between the terminals listed below and A15 starter generator case: X1 Terminal 1 X1 Terminal 2 X1 Terminal 3 X1 Terminal 4 X1 Terminal 5 X1 Terminal 6 If less that the specified value Replace the A15 starter generator. If the test passed
Test for infinite resistance between the terminals listed below: X1 Terminals 1 and 3 X1 Terminals 1 and 2 X1 Terminals 4 and 6 If less that the specified value Replace the A15 starter generator. If infinite Refer to Circuit/System Testing below.

Perform the Diagnostic Repair Verification after completing the repair.

«Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement)
«Control Module References»(/buick/lacrosse/ii-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The high voltage contactor relay is closed.

The drive motor control module detects excessive current flow through the switched portion of the insulated gate bipolar transistor.

DTC P0A78 is a Type B DTC.
The hybrid powertrain control module opens the high voltage contactor relay.

DTC P0A78 is a Type B DTC.

Schematic Reference

«Hybrid Controls Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Energy Storage Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

If the DTC is set, clear DTC; Turn the ignition OFF for 2 minutes. Turn the ignition ON, Operate vehicle within conditions for running and setting DTC. If the DTC resets, go to Circuit/System Testing below.

Perform the «High Voltage Disabling»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) procedure.
Remove the 3-phase cables from the K59 starter generator control module.
Test for infinite resistance between the 3-Phase cable terminals listed below and ground for each phase of the drive motor generator battery cable: X8 phase U terminal X7 phase V terminal X6 phase W terminal If less than infinite resistance, test each phase of the drive motor generator battery cable for a short to ground. If the cables test normal, replace the A15 starter generator.
Disconnect the 3-phase cables from the A15 starter generator.
Test for infinite resistance between the 3-Phase circuits listed below for each phase of the Drive Motor Generator Battery Cable: Phase U and phase V Phase V and phase W Phase W and phase U If less than infinite resistance, replace the Drive Motor Generator Battery Cable.
Replace the A15 starter generator and retest for the DTC. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

«Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement) for starter generator replacement.
«Drive Motor Generator Battery Cable Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system) for 3-Phase Cable Assembly replacement.
«Control Module References»(/buick/lacrosse/ii-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The 14V power module has 2 current sensors, one for input and one for output current measurements. This diagnostic checks the input current sensor. These current sensors are internal to the 14V power module and are not serviced separately from the generator control module.

The ignition is ON.
14V Power Module Status is Normal.
Ignition voltage is between 9-16V.

P0A88

14 volt power module input current is Less than 0.5 amp for greater than 2 seconds.

P0A89

14 volt power module input current is greater than 22.5 amps for greater than 2 seconds.

DTCs P0A88 and P0A89 are Type B DTCs.
Autostop disabled.
Autostart disabled.
Power regeneration disabled.

DTCs P0A88 and P0A89 are Type B DTCs.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

If the DTC is set, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The 14V power module has a voltage sensor that constantly monitors system output voltage. This diagnostic is intended to check the output voltage sensor's signal voltage, not the 12V system voltage. This sensor is internal to the 14V power module and is not serviced separately from the generator control module.

The ignition is ON.
14V Power Module Status parameter is Normal.
Ignition voltage is between 9-16V.

P0A8D

14V Power Module output voltage sensor value is less than 1 volt for greater than 2 seconds.

P0A8E

14V Power Module output voltage sensor value is greater than 20 volts for greater than 2 seconds.

DTCs P0A8D and P0A8E are Type B DTCs.

P0A8E

The charging system light will illuminate, and Service Battery Charging System will display on the Driver Information Center.

DTCs P0A8D and P0A8E are Type B DTCs.

P0A8D

14V Power Module output voltage sensor value is greater than 1.5 volts.

P0A8E

14V Power Module output voltage sensor value is less than 19.5 volts.

This DTC may set due to an open 175 amp fuse in the X50A fuse block-underhood.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

P0A8E

If the DTC is set, replace the K59 starter generator control module.

P0A8D

Ignition OFF, measure and record the battery voltage at the C1 12V battery terminals. The battery voltage should stabilize between 12.4 and 12.8 V within a few minutes of turning the ignition OFF. If not within the specified range, refer to «Battery Inspection/Test»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-except-hybrid) for Hybrid (HP6).
Ignition ON, observe the scan tool Ignition 1 Signal parameter in the 14V Power Module data list. The parameter should be within 4.5 volts of the Low Voltage Circuit Voltage measured at the C1 12V battery. If the voltage is not within the specified range, check the ignition circuit to the K59 starter generator control module for high resistance.
Remove the B+ terminal at the K59 starter generator control module.
Connect a test lamp between C1 12-volt positive battery post and the K59 starter generator control module terminal at the module.
Ignition ON, observe the scan tool parameter Low-Voltage Circuit Voltage in the 14V Power Module data list. The parameter should be within 0.5 volt of the actual 12-volt battery voltage. If the voltage is not within the specified range, replace the K59 starter generator control module.
Ignition OFF, remove the positive connection at the C1 12-volt battery.
Measure the resistance of the 14 V Power Module positive harness between the X10 connector at the K59 starter generator control module and the X50A Fuse block-Underhood connection. If the resistance is greater than 1.0 ohms, repair the open/high resistance condition in the 12-volt circuit. If the resistance is less than 1.0 ohms, Test the 175 amp fuse in the X50A fuse block-underhood. If the fuse tests good, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The 14V power module has a voltage sensor that constantly monitors system output voltage. This diagnostic is designed to test the performance of the voltage sensor. This sensor is internal to the 14V power module and is not serviced separately from the generator control module.

The ignition is ON.
14V Power Module Status parameter is Normal.
Ignition voltage is between 9-16V.

P0A8F

The difference between the Low Voltage Circuit Voltage and the ignition voltage value is greater than 4.5 volts for greater than 4 seconds.

The charging system light will illuminate, and Service Battery Charging System will display on the Driver Information Center.
DTC P0A8F is a Type B DTC.

DTC P0A8F is a Type B DTC.

This DTC may set due to low 12 V system voltage.
This DTC may set due to voltage stress to the underhood 175A fuse and junction block.

Schematic Reference

Power Distribution Schematics

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Ignition OFF, measure and record the battery voltage at the C1 12V battery terminals. The battery voltage should stabilize between 12.4 and 12.8 V within a few minutes of turning the ignition OFF. If not within the specified range, refer to «Battery Inspection/Test»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-hybrid-hp6) for Hybrid (HP6).
Ignition ON, observe the scan tool Ignition 1 Signal parameter in the 14V Power Module data list. The parameter should be within 4.5 volts of the Low Voltage Circuit Voltage measured at the C1 12V battery. If the voltage is not within the specified range, check the ignition circuit to the K59 starter generator control module for high resistance.

Remove the generator control module cable cover. Refer to «Generator Control Module Cable Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system) .
Remove the X10 B+ cable at the K59 starter generator control module, and tape the cable ring terminal.
Connect a 3A fused jumper wire between C1 12-volt positive battery post and the K59 starter generator control module X10 B+ terminal.
Connect C1 12V battery negative terminal.
Ignition ON, observe the scan tool parameter Low-Voltage Circuit Voltage in the 14V Power Module data list. The parameter should be within 0.5 volt of the actual 12-volt battery voltage. If the voltage is not within the specified range, replace the K59 starter generator control module.
Ignition OFF, remove the 3A fused jumper wire at the C1 12-volt battery.
Disconnect the C1 12V battery positive terminal and measure the resistance of the 14 V Power Module positive harness between the X10 connector at the K59 starter generator control module and the C1 12V battery positive terminal. If the resistance is greater than 1.0 ohms, repair the high resistance condition in the 12-volt circuit. If the resistance is less than 1.0 ohms, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The eAssist hybrid system has a starter generator also called a drive motor. The starter generator is mounted to the front of the engine and is mechanically connected to the crankshaft pulley by a serpentine belt.

The hybrid powertrain control module receives an engine RPM signal over serial data and compares that value to the starter generator rpm received from the drive motor control module. The hybrid powertrain control module uses a ratio of these two speeds to determine if the drive belt is missing or slipping.

Engine is running.
The system voltage is at least 9.5 V.
DTCs P0A3F, P0A40, P0B03, P0B0D, P0335, P0336, P0C19 or P1E0A are not set.

The hybrid powertrain control module detects a speed difference between the engine and the starter generator of greater than 1000 rpm.

The hybrid powertrain control module detects a speed difference between the engine and the starter generator of greater than 500 rpm multiple times on two consecutive ignition cycles with a Engine Off time of 30 minutes between key cycles.

DTC P0A90 is a Type A DTC.

DTC P0A90 is a Type A DTC.
The hybrid powertrain control module detects a speed difference between the engine and the starter generator of less than 500 rpm.

The ratio between the crankshaft and the drive motor speeds is 2.3 to 1. When using a scan tool to determine belt slip the engine (crankshaft) RPM value must be multiplied by 2.3 to approximate the starter generator speed.
Inspect the drive belt for cracks and oil contamination.
Test drive the vehicle through the different modes of operation, performing Autostop and Autostart cycles. Accelerate up to 50 mph and brake moderately, and listen for any audible belt squeal. If drive belt noise is noticed check the drive belt tensioner assembly for proper operation and installation.

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

If drive belt noise was noticed on an AutoStart, refer to «Drive Belt Tensioner Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-tensioner-diagnosis) .
Inspect the drive belt for cracks, wear and contamination. If the belt is not OK, replace the drive belt.
If the DTC resets, replace the A15 starter generator.

Perform the Diagnostic Repair Verification after completing the repair.

«Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement)
«Drive Belt Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-replacement)
«Drive Belt Tensioner Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-tensioner-replacement)

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The eAssist hybrid system has the ability to crank and start the engine using two different methods. The first method is a conventional 12 volt system. On every initial start up the conventional 12 volt starter and 12 volt battery are used to crank and start the engine.

The second starting method uses both the 115 Volt generator control and battery assembly, also called the hybrid EV battery pack, and the starter generator, also called the drive motor. The drive motor is a 3 phase AC induction machine. This device not only serves as a 115-volt AC generator, it is also used to provide engine power assist and to start the engine when in auto-stop mode. If the system is in the auto-stop mode and fails to restart with the drive motor, the 12 volt conventional starter will automatically be engaged to start the engine.

The drive motor can quickly rotate the engine to operating speed (800 RPM). The hybrid powertrain control module can detect a condition where the engine is stalling and command the drive motor to rotate the engine to prevent a stall.

Engine Running.

The hybrid powertrain control module detects that engine speed has fallen below a specific minimum speed indicating the engine has stalled.

DTC P0AB9 is a Type C DTC.

DTC P0AB9 is a Type C DTC.
Engine restarts with key cycle.

Any condition that causes the engine to stall and/or not start may set this DTC. Possible conditions include

Fuel conditions such as low level, low pressure, or contamination.
Engine conditions such as low compression.
Restricted exhaust or air intake systems.

Always inspect for DTCs that would cause an engine stall and/or no start condition.

This DTC may set if the vehicle is powered off while driving.

Schematic Reference

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Verify that no other DTCs are set. If other DTCs are set, diagnose them first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Start the engine. The engine should start and run. If the engine fails to start, or stalls, diagnose the engine system. Refer to «Engine Cranks But Does Not Run»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
If the DTC is set, and the engine is running smoothly, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This is an internal fault detection of the generator control module. This fault is handled inside the generator control module and no external circuits are involved.

DTCs P1A90, P1A91, P1A92, P1A71, P1A72, P1A73, P0A2B, P0A2C, P0A2D, P0A2F, P0AEE, P0AEF, P0AF0, P0C11 and P262B are not set.
Ignition voltage is between 9-16V.
The drive motor control module and the hybrid powertrain control module are awake.

P0AEE

The engine OFF time is greater than 8 hours.

P0AEE

The temperature average of the drive motor temperature sensor and 14V power module temperature sensors 1 and 2 are 20°C (36°F) different from the Phase U DC/AC Inverter Temperature value.

P0AEF

The inverter phase temperature sensor 1 is greater than 150°C (302°F) for 3 seconds.

P0AF0

The inverter phase temperature sensor 1 is less than -70°C (-94°F) for 3 seconds.

DTCs P0AEE, P0AEF, and P0AF0 are Type B DTCs.
The power inverter module limits the maximum torque of the starter generator to 10.8 N.m (95.6 lb in).
Autostop will be disabled.

DTCs P0AEE, P0AEF, and P0AF0 are Type B DTCs.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Allow the vehicle to cool to ambient temperature by leaving the ignition OFF for at least 8 hours.
Ignition ON, if the DTC is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Relay Switch B+	P2797 **	P2797
Relay Coil Ignition	P0B09 **	P0B09
Relay Coil Control	P0B09 *	P0B09	P0B09
Relay Switch Control	P2797 **	P2797	P2797 *
Component Ground		***
* Auxiliary Transmission Fluid Pump - always On Will open the fuse * Auxiliary Transmission Fluid Pump - inoperative

The transmission fluid pump - auxiliary is used to maintain transmission fluid line pressure to the transmission during Autostop mode. The transmission fluid pump - auxiliary is externally mounted to the transmission case assembly. The hybrid powertrain control module controls the auxiliary pump by providing the ground path to the transmission pump relay - auxiliary coil control circuit.

Ignition voltage is greater than 9 V.

The generator control module detects an invalid voltage on the auxiliary transmission fluid pump relay control circuit for greater than 1 second.

DTC P0B09 is a type B DTC.
Autostop is disabled.

DTC P0B09 is a type B DTC.

Transmission Fluid Pump Relay Underhood Electrical Center Terminal Identification
Front of Vehicle
Left Side of Vehicle	Control	Load	Right Side of Vehicle
Left Side of Vehicle	B+	Ignition	Right Side of Vehicle

Schematic Reference

Description and Operation

«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Electrical Center Identification Views»(/buick/lacrosse/ii-2009-2013/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-electrical-center-identification-views)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON.
Verify the auxiliary transmission fluid pump relay turns on and off/clicks when commanding the auxiliary transmission fluid pump relay ON and OFF with a scan tool. If the relay does not click Refer to Circuit/System Testing below. If the relay clicks All OK.

Ignition OFF, disconnect the KR86 Transmission Fluid Pump Relay - Auxiliary, Ignition ON.
Verify a test lamp illuminates between the ignition circuit terminal 86 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the ignition circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the ignition circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, test or replace the KR86 Transmission Fluid Pump Relay - Auxiliary. If the test lamp illuminates
Connect a test lamp between the ignition circuit terminal 86 and the control circuit terminal 85.
Verify the test lamp turns ON and OFF when commanding the Auxiliary Transmission Pump Relay ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the X2 harness connector at the K59 starter generator control module, ignition ON. Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Ignition OFF. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K59 starter generator control module. If the test lamp is always ON Ignition OFF, disconnect the harness connector at the K59 starter generator control module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K59 starter generator control module. If the test lamp turns ON and OFF
Replace the K59 starter generator control module.

Ignition OFF, disconnect the KR86 Transmission Fluid Pump Relay - Auxiliary.
Test for 85-130 ohms between terminals 85 and 86. If less than 85 ohms or greater than 130 ohms Replace the relay. If between 85-130 ohms
Test for infinite resistance between the terminals listed below: 30 and 86 30 and 87 30 and 85 85 and 87 If less than infinite resistance Replace the relay. If infinite resistance
Install a 3 A fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground.
Test for less than 2 ohms between terminals 30 and 87. If 2 ohms or greater Replace the relay. If less than 2 ohms
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

«Relay Replacement (Within an Electrical Center)»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions__relay-replacement-within-an-electrical-center) , «Relay Replacement (Attached to Wire Harness)»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) for Transmission Fluid Pump Relay - Auxiliary replacement, Within an Electrical Center
«Control Module References»(/buick/lacrosse/ii-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This is an internal fault detection of the generator control module. This fault is handled inside the generator control module and no external circuits are involved.

The control module runs the program to detect an internal fault when the drive motor control module is awake and the engine is off.

The control module has detected an internal malfunction.
The motor phase U current is greater than 440 amps or less than -440 amps.
The motor phase W current is greater than 440 amps or less than -440 amps.

DTCs P0BE6, P0BE7, P0BE8, P0BEE, P0BEF, and P0BF0 are Type B DTCs.
The generator control module operates in a reduced power mode.
Regenerative breaking torque is reduced.
Autostop and electric power assist are disabled.

DTCs P0BE6, P0BE7, P0BE8, P0BEE, P0BEF, and P0BF0 are Type B DTCs.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

If the DTC is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The drive motor control module operates the starter generator, also referred to as the drive motor, based upon hybrid powertrain control module commands. The drive motor control module controls the speed and output torque of the starter generator through the sequencing actuation of high current switching transistors called insulated gate bipolar transistors. The starter generator operates utilizing 3-phase alternating current (AC) electricity. Each insulated gate bipolar transistors operates a single phase of the starter generator. Each phase is individually identified as U, V and W. The drive motor control module monitors the current of phase U and W. The drive motor control module uses logic to calculate phase V current values. This information is used in order to detect over current conditions.

Because all starter generator phase circuits are electrically joined together, they should each flow about the same amount of current. The drive motor control module performs a mathematical calculation to verify that the phase current sensors are accurate. If the current sensors indicate about the same amount of phase current, the sum of the calculation should be near zero. If the currents are not similar, this DTC will set.

The ignition is ON.
The high voltage contactor relay is closed.
DTCs P0BE6, POBE7, POBE8, P0BEE, POBEF, or P0BF0 are not set.

The sum of the 3 phase current calculations is greater than 40 A.

DTC P0BFD is a Type B DTC.
The generator control module operates in a reduced power mode.
Regeneration is limited.
Autostop and electric assist is disabled.

DTC P0BFD is a Type B DTC.

The 14V power module remains active.

Schematic Reference

«Hybrid Controls Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Energy Storage Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system)

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Perform the «High Voltage Disabling»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) procedure.
Remove the 3-phase cables from the K59 generator control module.
Test for infinite resistance between each of the 3-phase circuit terminals listed below and ground: X8 phase U terminal X7 phase V terminal X6 phase W terminal If not the specified value, disconnect the 3-phase cables from the A15 starter generator, and test the AC circuits for a short to ground. If the circuit tests normal, replace the A15 starter generator. Replace the K59 starter generator control module. If the DTC resets replace the A15 starter generator.

Perform the Diagnostic Repair Verification after completing the repair.

«Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement)
«Drive Motor Generator Battery Cable Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system) for 3-Phase Cable Assembly replacement
«Control Module References»(/buick/lacrosse/ii-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The drive motor control module operates the starter generator, also referred to as the drive motor based upon hybrid powertrain control module commands. The drive motor control module controls the speed and output torque of the starter generator through the sequencing actuation of high current switching transistors called insulated gate bipolar transistors. Each insulated gate bipolar transistor assembly is monitored for overcurrent conditions.

The ignition is ON.

One or more phase currents are greater than ±396 A.

DTC P0C01 is a Type B DTC.
The starter generator regeneration and power assist functions are disabled.

DTC P0C01 is a Type B DTC.

The 14 V power module will still be active.

Schematic Reference

«Hybrid Controls Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Energy Storage Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system)

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Verify DTCs P0BE6, P0BE7, P0BE8, P0BEE, P0BEF, and P0BF0 are not set.
If the DTC is set, clear DTC; Turn the ignition OFF for 2 minutes. Turn the ignition ON, Operate vehicle within conditions for running and setting DTC. If the DTC resets, go to Circuit/System Testing below.

Perform the «High Voltage Disabling»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) .
Ignition OFF, disconnect the 3-phase cables from the K59 starter generator control module.
Test for infinite resistance to 3-phase circuit terminals listed below and ground: X8 phase U terminal X7 phase V terminal X6 phase W terminal If not the specified value, disconnect the 3-phase cables from the A15 starter generator, and test the 3-phase circuit for a short to ground. If the circuit tests normal, replace the A15 starter generator motor.
Replace the K59 starter generator control module. If the DTC resets replace the A15 starter generator.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement)
«Drive Motor Generator Battery Cable Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system) for 3-Phase Cable Assembly replacement
«Control Module References»(/buick/lacrosse/ii-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The drive motor control module operates the starter generator, also referred to as the drive motor. The drive motor control module controls the speed and output torque of the starter generator through the sequencing actuation of high current switching transistors called insulated gate bipolar transistors. Each insulated gate bipolar transistor assembly is monitored for overcurrent conditions.

The ignition is ON.
The high voltage input to the generator control module is above 50 volts.
DTCs P0BE6, POBE7, POBE8, P0BEE, POBEF, P0BF0, or P0BFD are not set.
The drive motor control module has applied greater than or equal to 25A to the drive motor.

The drive motor control module detects at least one U-V-W phase current values is less than 9A.

DTC P0C05 is a Type B DTC.
The starter generator regeneration and power assist functions are disabled.

DTC P0C05 is a Type B DTC.

The 14v power module remains active.

Schematic Reference

«Hybrid Controls Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Energy Storage Schematics»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system)

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Perform the «High Voltage Disabling»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) procedure.
Remove the 3-phase cable assembly from the K59 starter generator control module.
Test for less than 0.5 ohms at each phase by measuring between the following circuits at the cable with a DMM: Phase U and phase V Phase U and phase W Phase V and phase W If within the specified value
Inspect the 3-phase drive motor generator battery cable terminal fasteners at the K59 starter generator control module. If any fasteners were loose and no arc-flash damage is present Torque the fasteners and re-assembly the vehicle. Retest for the DTC. If any fasteners were loose and arc-flash damage is present Replace the K59 starter generator control module assembly and the 3-phase drive motor generator battery cable assembly. If not within the specified value
Disconnect the 3-phase drive motor generator battery cable assembly from the A15 starter generator. Test each cable for continuity from the starter generator connection terminal to the K59 starter generator control module connection terminal. If you measure greater than 0.5 ohms Replace the 3-phase drive motor generator battery cable assembly.
Replace the A15 starter generator and retest for the DTC. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

«Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement) for starter generator replacement.
«Drive Motor Generator Battery Cable Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system) for 3-Phase Cable Assembly replacement.
«Control Module References»(/buick/lacrosse/ii-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The inverter supply voltage circuit detects the loss of the bias power supply to the insulated gateway bi-polar transistors. This is an internal fault detection of the generator control module. This fault is handled inside the generator control module and no external circuits are involved.

The ignition is on and greater than 7 volts.
The drive motor control module is awake.

The generator control module does not detect voltage at the insulated gate bi-polar transistor bias supply.

DTC P0C0B is a Type A DTC.
The drive motor will be disabled.

DTC P0C0B is a Type A DTC.

The 14V power module remains active.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Verify DTC P0562 is not set. If the DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
If DTC P0C0B is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The drive motor control module operates the starter generator, also referred to as the drive motor, based upon hybrid powertrain control module commands. The drive motor control module controls the speed and output torque of the drive motor through the sequencing actuation of high current switching transistors called insulated gate bipolar transistors. The drive motor operates utilizing 3 phase AC. Each insulated gate bipolar transistor operates a single phase of the drive motor. Each phase is individually identified as U, V and W. The drive motor control module monitors the temperature of the switching transistors in order to detect inverter module overtemperature conditions. The generator control module is air cooled.

The drive motor control module and hybrid powertrain control module are awake.
DTC P0AEE, P0AF0, and P0AEF are not set.

The Phase U DC/AC Inverter Temperature 1 is greater than 118°C (245°F) for 5 seconds.

DTC P0C11 is a Type B DTC.
The hybrid powertrain control module system starts to reduce the maximum torque beginning at 110°C (230°F) linearly down to 0 N.m(0 lb in) as the drive motor stator temperature approaches 120°C (248°F).

DTC P0C11 is a Type B DTC.

Ask about the customer's driving habits, trailer towing, etc.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Verify P0C32, P0A81, P0A84, P0A85 or P0A7E are not set.
Ignition On, verify with a scan tool that the Phase U DC/AC Inverter Temperature 1 is less than 118°C (245°F). If greater than 118°C (245°F), inspect for proper operation of the hybrid battery cooling fan and ducts. If the hybrid cooling system tests normal, Reprogram K59 starter generator control module. If the DTC resets replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the starter generator control module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The starter generator also called the drive motor is controlled by the drive motor control module. The drive motor control module constantly monitors the requested torque and the delivered torque of the drive motor.

DTCs P0BFD, P0BE6, P0BE7, P0BE8, P0BEE, P0BEF, P0BF0, P1AE8, P1AE9, P1AEC, P1B0D, P0C52, P0C53, P0C5C, P0C5D, P0A3F, P1B03 and P0A40 are not set
Drive motor is commanded to develop torque.

The drive motor control module has detected that the difference between drive motor torque commanded and delivered is greater than 36 N.m (27 lb ft).

DTC P0C19 is a Type B DTC.
Commanded motor torque is limited to below 36 N.m (27 lb ft).

DTC P0C19 is a Type B DTC.

Seized or binding engine
Seized or binding accessory drive belt
Seized or binding starter generator

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Start the engine. DTC P0C19 should not be set.
Verify DTC P0A90 is not set. If the DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Verify the engine or AC compressor is not seized or binding. If the engine is seized or binding, refer to «Symptoms - Engine Mechanical»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) . If the AC Compressor is seized or binding, refer to «Noise Diagnosis - Air Conditioning (A/C) System»(/buick/lacrosse/ii-2009-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__noise-diagnosis-air-conditioning-ac) .
Verify the A15 starter generator is not seized or binding.
If DTC P0C19 is set, replace the A15 starter generator.

Perform the Diagnostic Repair Verification after completing the repair.

Starter Generator Replacement for starter generator replacement.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The generator control and battery module assembly contains a high voltage contactor. The high voltage contactor allows the high voltage DC batteries to be connected to the vehicle and safely contain the high voltage DC within the generator control and battery module assembly. The high voltage contactor is connected in series with the positive side of the DC voltage potential of the high voltage battery. The hybrid powertrain control module supplies ground to the control circuit of the high voltage contactor to close.

High Voltage Contactor Relay is commanded open.

The high voltage circuit is greater than 65 V for 6.5 seconds after the contactor has been commanded open.

DTC P0C76 is a Type A DTC.
A clear DTC command will not clear this DTC or the Action Taken.

DTC P0C76 is a Type A DTC.

A clear DTC command will not clear this DTC or the Action Taken.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Refer to Hybrid\EV Battery Voltage Present . If the contactors test normal, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The 14V power module has 2 current sensors, one for input and one for output current measurements. This diagnostic checks the output current sensor. These current sensors are internal to the 14V power module and are not serviced separately from the generator control module.

Ignition is ON.
14V Power Module Status parameter is Normal.
Ignition voltage is between 9-16V.

P0C9E

Low Voltage Circuit Current is less than 2 amps for greater than 2 seconds.

P0C9F

Low Voltage Circuit Current is greater than 123 amps for greater than 2 seconds.

DTCs P0C9E and P0C9F are Type B DTCs.

P0C9F

The 14V power module stops supplying power to the 12V system.
The charge indicator will illuminate.

DTCs P0C9E and P0C9F are Type B DTCs.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

If the DTC is set, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The 14V power module has switching transistors that allows it to convert high voltage from the Hybrid Battery to 12 volts. This diagnostic is designed to test for an electrical short in the MOSFET transistors. The transistors are internal to the 14V power module and cannot be serviced separately from the generator control module.

The ignition is ON and the 14V Power Module is enabled.

The 14 V Power Module has detected a transistor failure for 25 mS.

The 14V power module stops supplying power to the 12V system.
The charging system light will illuminate, and Service Battery Charging System will display on the Driver Information Center.
DTC P0CA2 is a Type A DTC.

DTC P0CA2 is a Type A DTC.
14 V Power Module detects no transistor failures for 5 seconds.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

If the DTC is set, program the K59 Starter Generator Control Module. If the DTC resets, go to Circuit/System Testing below.

Perform the «High Voltage Disabling»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) procedure.
Remove the 3-phase cables from the K59 starter generator control module.
Test for infinite resistance between the 3-Phase cable terminals listed below and ground for each phase of the drive motor generator battery cable: X8 Phase U terminal X7 Phase V terminal X6 Phase W terminal If less than infinite resistance, test each phase of the drive motor generator battery cable for a short to ground. If the cables test normal, replace the A15 starter generator.
Retest for the DTC. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The 14V power module has 2 internal current sensors, one for input and one for output current measurements. The 14 volt power module monitors both input and output current, and then makes a correlation between them. This diagnostic will check range performance malfunctions of one or both of the current sensors. These current sensors are internal to the 14V power module and are not serviced separately from the generator control module.

Ignition is ON.
Ignition voltage is between 9-16V.

The difference between the calculated input power and calculated output power of the two current sensors is greater than 0.4 kW for greater than 4 seconds.

DTC P0CC5 is a Type B DTC.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

If the DTC is set, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This diagnostic applies to internal microprocessor integrity conditions within the hybrid powertrain control module. This is an internal fault detection of the hybrid powertrain control module and no external circuits are involved.

Ignition is ON.
The system voltage is greater than 9.5 V.

The control module has detected an internal malfunction.

DTC P15F0 is a Type A DTC.
The hybrid powertrain control module opens the high voltage contactor relay.

DTC P15F0 is a Type A DTC.

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

If the DTC is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM). The hybrid powertrain control module (HPCM) sends an engine torque requested message to the ECM over GMLAN. The ECM monitors the data to verify that the indicated engine torque requested calculation is correct. The ECM processor monitors the data to verify that the engine torque command is correct.

Ignition is ON.
The system voltage is greater than 9.5 V.
DTC U1817 is not set.

The control module has detected an internal malfunction.

DTC P15F2 is a Type A DTC.
The HPCM commands the battery energy control module (BECM) to open the high voltage contactor relays.

DTC P15F2 is a Type A DTC.

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Note. Diagnose and repair any communication DTCs prior to performing this testing.

Ignition ON.
Verify DTC P15F2 is not set. If the DTC is set Program the K20 Engine Control Module. Verify the DTC does not set. If the DTC sets, replace the K20 Engine Control Module. If the DTC does not set All OK If the DTC is not set
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for K20 ECM Module replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The generator control module, also called the starter generator control module, is comprised of the following three control modules; the hybrid powertrain control module, 14 volt power module and the drive motor control module. These three control modules are non serviceable and are part of the generator control module.

This is an internal fault detection of the hybrid powertrain control module and no external circuits are involved.

Ignition is ON.
The system voltage is greater than 9.5 V.
DTC U1817 is not set.

The control module has detected an internal malfunction.

DTC P15F4 is a Type A DTC.
The HPCM commands the battery energy control module (BECM) to open the high voltage contactor relays.

DTC P15F4 is a Type A DTC.

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Note. Diagnose and repair any communication DTCs prior to performing this testing.

Ignition ON.
Verify DTC P15F4 is not set. If the DTC is set Program the K59 Starter Generator Control Module. Verify the DTC does not set. If the DTC sets, replace the K59 Starter Generator Control Module. If the DTC does not set All OK If the DTC is not set
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for K59 Starter Generator Control Module replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This is an internal fault detection of the hybrid powertrain control module and no external circuits are involved.

The ignition is ON.

The control module has detected an internal malfunction.

DTC P15F5 is a Type A DTC.
The hybrid powertrain control module opens the high voltage contactor relay.

DTC P15F5 is a Type A DTC.

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Verify that DTC P0562 is not set. If DTC is set, refer to «DTC B1325, B1330, B1420, B1424, B1517, C0800, C0895, C0899, C0900, C12E1, C12E2, P0560, P0562, or P0563»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-hybrid-hp6) for Hybrid (HP6).
If the DTC is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for generator control module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This is an internal fault detection of the hybrid powertrain control module and no external circuits are involved.

The system voltage is greater than 9.5 V.
Ignition is ON.

The control module has detected that the redundant data does not match the primary data.

DTC P16F3 is a Type A DTC.
The hybrid powertrain control module opens the high voltage contactor relay.

DTC P16F3 is a Type A DTC.

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

If the DTC is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The generator control module contains DC high voltage capacitors and a resistor circuit intended to discharge the electrical energy stored within those capacitors. Whenever the high voltage contactors are opened, the hybrid powertrain control module connects the internal resistor circuit across the capacitor circuit. The level of the high voltage is monitored by the hybrid powertrain control module before and after the resistor circuit has been connected. If the voltage level remains high for too long, the hybrid powertrain control module sets this DTC and then commands the motor control module to connect the drive motor generator 3 phase circuits across the DC high voltage positive and negative circuits thereby discharging the capacitors.

High Voltage Contactors are commanded Open.

Within 300 milliseconds after commanding contactors open, the high voltage bus voltage fails to decrease by at least 18 V.

Within 300 milliseconds after commanding contactors open, the high voltage bus voltage is greater than 60 V.

The active bus discharge circuit status is disabled.

DTC P1A56 is a Type B DTC.
The drive motor control module is commanded to discharge the capacitor through the drive motor generator 3 phase stator circuits.

DTC P1A56 is a Type B DTC.

A high-pitched whine may emanate from the drive motor whenever the HV DC capacitance is discharged through the drive motor stator circuits.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Verify other DTCs are not set. If other DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
If the DTC is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The second starting method uses the 115 Volt generator control and battery assembly also called the hybrid battery and the starter generator also called the drive motor. The drive motor is a 3 phase AC induction machine. This device not only serves as a 115-volt AC generator, it is also used to provide engine power assist and to start the engine when in auto-stop mode. If the system is in the auto-stop mode and fails to restart with the drive motor, the 12 volt conventional starter will automatically be engaged to start the engine.

Ignition is ON and the vehicle is in autostop.

The hybrid powertrain control module detects that an autostart failed to take place successfully.

DTC P1A6F is a Type B DTC.
The 12 V starter will be engaged to start the engine and autostop will be disabled.

DTC P1A6F is a Type B DTC.

A slipping drive motor belt can cause belt noise on an AutoStart, inspect the drive belt tensioner assembly for proper operation and installation.

Schematic Reference

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

If drive belt noise was noticed on an AutoStart, refer to «Drive Belt Tensioner Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-tensioner-diagnosis) .
Verify that no other hybrid control module or engine control modules DTCs are set. If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
If the DTC is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The 14V power module constantly monitors its temperature to protect against overheat conditions. The module also monitors the performance of the temperature sensors to assure they are working properly. These sensors are internal to the 14V power module and are not serviced separately from the generator control module.

The Ignition is ON.
Ignition voltage is between 9-16V.

P1A71

DTCs P1A90, P1A91, P1A92, P1A71, P1A72, P1A73, P0A2B, P0A2C, P0A2D, P0A2F, P0AEE, P0AEF, P0AF0, P0C11, and P262B are not set.
Ignition must be off for 8 hours or more.

P1A71

14V Power Module Temperature Sensor 2 has a value of 20°C greater than the average value of 14V Power Module Temperature Sensor 1, Motor Generator Unit Temperature, and the Inverter Temperature for greater than 4 seconds.

P1A72

14V Power Module Temperature Sensor 2 is greater than 145°C (293°F) for greater than 4 seconds.

P1A73

14V Power Module Temperature Sensor 2 is less than -65°C (-85°F) for greater than 4 seconds.

DTCs P1A71, P1A72, or P1A73 are Type B DTCs.
The 14V power module stops supplying power to the 12V system.
The charging system light will illuminate, and Service Battery Charging System will display on the Driver Information Center.

DTCs P1A71, P1A72, or P1A73 are Type B DTCs.

P1A72

14V Power Module Temperature Sensor 2 is less than 140°C (284°F).

P1A73

14V Power Module Temperature Sensor 2 is greater than -60°C (-76°F).

Verify 14V Power Module Temperature Sensor 2 reads between -59°C (-74°F) and +139°C (+282°F) and is within 20°C (36°F) of the average of 14V Power Module Temperature Sensor 1, Drive Motor Temperature, and 14V Power Module Temperature Sensor 2 after ignition has been off for 8 hours.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

If the DTC is set, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The Ignition is ON.
Ignition voltage is between 9-16V.

P1A90

DTCs P1A90, P1A91, P1A92, P1A71, P1A72, P1A73, P0A2B, P0A2C, P0A2D, P0A2F, P0AEE, P0AEF, P0AF0, P0C11, and P262B are not set.
The Ignition has been off for 8 hours.

P1A90

14V Power Module Temperature Sensor 1 has a value of 20°C greater than the average value of 14V Power Module Temperature Sensor 2 and Drive Motor Temperature for greater than 4 seconds.

P1A91

14V Power Module Temperature Sensor 1 is greater than 145°C (293°F) for greater than 4 seconds.

P1A92

14V Power Module Temperature Sensor 1 is less than -65°C (-85°F) for greater than 4 seconds.

DTCs P1A90, P1A91, or P1A92 are Type B DTCs.

P1A91

The 14V power module stops supplying power to the 12V system.
The charging system light will illuminate, and Service Battery Charging System will display on the Driver Information Center.

DTCs P1A90, P1A91, or P1A92 are Type B DTCs.

P1A91

14V Power Module Temperature Sensor 1 is less than 140°C (284°F).

P1A92

14V Power Module Temperature Sensor 1 is greater than -60°C (-76°F).

Under normal operation, the scan tool parameter 14V Power Module Temperature Sensor 1 should be between -59°C (-74°F) and +139°C (+282°F), and be within 20°C (36°F) of the average of 14V Power Module Temperature Sensor 2 and Drive Motor Temperature after ignition has been off for 8 hours.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

If the DTC is set, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The drive motor control module operates the starter generator based upon hybrid powertrain control module information.

The vehicle control modules or sensors monitor the system voltage to verify the system voltage is within the normal operating range.

The Ignition is ON.

P1ADE

Drive motor control module ignition voltage is less than or equal to 10 V for 6 seconds.

P1ADF

Drive motor control module ignition voltage is greater than 18 Volts for 5 seconds.

DTCs P1ADE and P1ADF are Type C DTCs.

P1ADE

The hybrid powertrain control module opens the high voltage contactor relay.

DTCs P1ADE and P1ADF are Type C DTCs.

A high or low voltage DTC set Or Voltage value in multiple modules/sensors indicates a concern in the charging system.
A battery charger or vehicle jump start may have set DTC P1ADF.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Ignition OFF, measure and record the battery voltage at the C1 12V battery terminals. The battery voltage should stabilize between 12.4 and 12.8 V within a few minutes of turning the ignition OFF. If not within the specified range, refer to «Battery Inspection/Test»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-hybrid-hp6) for Hybrid (HP6).
Engine running, accessories OFF, measure and record the battery voltage at the C1 12V battery terminals. The voltage should be at least 1 V greater than the voltage measured in step 1 but less than 15 V. If not within the specified range, refer to «Charging System Test»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-hybrid-hp6) for Hybrid (HP6).
Observe the drive motor control module ignition 1 signal voltage parameter with a scan tool. The voltage readings should be within 1 V of the 12V battery voltage.

Ignition OFF, disconnect the harness connectors at the K59 starter generator control module.
Ignition OFF, scan tool disconnected, open and close the driver door and wait 1 minute. Test for less than 10 ohms between each ground circuit terminal at the K59 starter generator control module harness and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
Test for 10-18V between each B+ circuit terminal at the K59 starter generator control module harness and ground. If less than the specified range, test the B+ circuit for a short to ground or an open/high resistance.
Ignition ON, test for 10-18 V between each ignition circuit terminal and ground. If less than the specified range, test the ignition circuit for a short to ground or an open/high resistance.
If all circuits test normal, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The drive motor control module operates the starter generator based upon generator control module commands. The hybrid powertrain control module is able to detect out of range low or out of range high conditions on the high voltage sensor circuit.

The Ignition is ON.
The high voltage contactor relay is closed.

P1AE8

With the hybrid/EV battery system contactor closed, the starter generator control module detects high voltage sensor voltage less than 30V.

P1AE9

The drive motor control module detects high voltage sensor voltage greater than 190V.

DTCs P1AE8 and P1AE9 are Type B DTCs.
The hybrid powertrain control module opens the high voltage contactor relay.
The battery indicator light will illuminate.

DTCs P1AE8 and P1AE9 are Type B DTCs.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

If the DTC is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The drive motor control module operates the starter generator based upon generator control module commands. The hybrid powertrain control module monitors the high voltage measurement and then will broadcast the high voltage measurement over serial data.

P1AEC

The drive motor control module compares the values in order to verify the hybrid battery high voltage measurement is accurate.

P1AEE

The hybrid powertrain control module monitors for high voltage that is greater than the system allows during normal operation.

P1AEC

DTC P1AE8 or P1AE9 is not set

AND

High voltage is available and valid

AND

Ignition is On

AND

The high voltage contactor relays are closed.

P1AEE

Ignition voltage is greater than 7V.

P1AEC

The difference between high voltage sensed and high voltage battery voltage measured is greater than 15V

AND

The difference between high voltage sensed and the sum of the mid-pack voltages is greater than 10V.

P1AEE

The high voltage sensor voltage is greater than 150V

Hardware Overvoltage is detected.

DTCs P1AEC and P1AEE are Type B DTCs.
The hybrid powertrain control module opens the high voltage contactor relay.

DTCs P1AEC and P1AEE are Type B DTCs.

Conditions such as loss of battery energy control module power or ground or removal of the high voltage manual disconnect while the vehicle was driving could create a voltage surge that may set DTC P1AEE. History DTC P1AEE may indicate that the high voltage contactor relays opened while large current flow was present.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Verify that DTCs P0ABB, P0ABC, or P0ABD is not set. If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
If the DTC is set, program the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The vehicle is equipped with a high voltage isolation monitor feature. The purpose of the isolation monitor is to test the resistance between the high voltage positive and negative direct current (DC) bus and chassis ground. The isolation monitoring system measures the resistance between the high voltage system and chassis ground in the following way: The isolation monitoring system measures voltage potential difference between the positive battery mid pack voltage and chassis ground as well as the voltage difference between negative battery mid pack voltage and chassis ground. These voltage values are used by the Starter/Generator Control Module to calculate a resistance value between the high voltage bus and the chassis ground. If this resistance value is too low, a high voltage isolation fault has occurred.

Internal battery voltage sensor value is greater than 100 V
None of the following DTCs are set: P0AA8, P0AAA, P1AE8, P1AE9, P1AEC, P1E0D, P1E10, P1E11, P1E13, P1E14

The calculated resistance between the high voltage DC systems and vehicle chassis ground less than 225.6K ohms

DTC P1AF0 is a type B DTC.
If the DTC sets while there is a loss of communication with the sensing and diagnostic module (SDM), the Starter/Generator Control Module will record the fault as a crash event and the DTC will become latched.

DTC P1AF0 is a type B DTC.
If the DTC is set as a latched DTC, the crash event must be cleared before the DTC will clear.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

EL-48900 HEV Safety Kit
EL-50772 Insulation Multimeter

For equivalent regional tools, refer to Special Tools .

WARNING

Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed. The High Voltage Disabling procedure includes the following steps: Identify how to disable high voltage. Identify how to test for the presence of high voltage. Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed. Before working on any high voltage system, be sure to wear the following Personal Protection Equipment: Safety glasses with appropriate side shields when within 15 meters (50 feet) of the vehicle, either indoors or outdoors. Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors. Visually and functionally inspect the gloves before use. Wear the Insulation gloves with leather protectors at all times when working with the high voltage battery assembly, whether the system is energized or not. Failure to follow the procedures may result in serious injury or death.

WARNING

The eAssist battery pack assembly will utilize an exchange program. Please consult the most recent revision of bulletin/PI# PIC5520, available in Service Information (SI), for a list of approved eAssist battery pack assembly service procedures. Components that may be removed and serviced without exchanging the complete battery pack assembly are identified in the bulletin/PI. Please contact the GM Technical Assistance Center (1-877-446-8227) if you have any questions.

Ignition OFF, disable high voltage at the A4 Hybrid/EV Battery Pack. Refer to «High Voltage Disabling»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system__high-voltage-disabling) .
Disconnect the U, V, and W three phase lugs at the K59 Starter/Generator Control Module.
Test for greater than 400K ohms between the terminals listed below and chassis ground with the EL-50772 insulation multimeter set on the Isolation test setting: 3 phase cable terminal U - cable side lug 3 phase cable terminal V - cable side lug 3 phase cable terminal W - cable side lug If 400K ohms or less Disconnect the U, V, and W three phase lugs at the A15 Starter/Generator. Test for greater than 400K ohms between the U, V, and W three phase studs at the A15 Starter/Generator and chassis ground with the EL-50772 insulation multimeter set on the Isolation test setting. If 400K ohms or less, replace the A15 Starter/Generator. If greater than 400K ohms Replace the high voltage 3 phase cables. If greater than 400K ohms
Test for greater than 400K ohms between the terminals listed below and chassis ground with the EL-50772 insulation multimeter set on the Isolation test setting: 3 phase terminal U - K59 Starter/Generator Control Module stud 3 phase terminal V - K59 Starter/Generator Control Module stud 3 phase terminal W - K59 Starter/Generator Control Module stud If 400K ohms or less Disconnect and remove the two wiring junction blocks from the A4 Hybrid/EV Battery Pack. Test for greater than 400K ohms between the U, V, and W three phase studs at the K59 Starter/Generator Control Module and chassis ground with the EL-50772 insulation multimeter set on the Isolation test setting. If 400K ohms or less, replace the K59 Starter/Generator Control Module. If greater than 400K ohms Replace the two wiring junction blocks. If greater than 400K ohms
Replace the C4A Hybrid/EV Battery Section 1 and C4B Hybrid/EV Battery Section 2.

Perform the Diagnostic Repair Verification after completing the repair.

«Drive Motor Generator Battery Cable Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system)
«Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement)
«Generator Battery Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system)
«Control Module References»(/buick/lacrosse/ii-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Starter/Generator Control Module replacement, programming, and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this repair.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The vehicle is equipped with a high voltage isolation monitor feature. The purpose of the isolation monitor is to test the resistance between the high voltage positive and negative direct current (DC) bus and chassis ground. The isolation monitoring system measures the resistance between the high voltage system and chassis ground in the following way. The starter/generator control module places an AC signal on the high voltage system and monitors its amplitude. A reduced amplitude return signal indicates a loss of resistance to chassis ground. This isolation monitor method is sometimes referred to as the active isolation monitor.

P1AF4

Power mode is RUN or CRANK.
Contactors are closed.

P1AF5

Power mode is RUN or CRANK.

P1AF4

The positive mid-pack voltage is less than 5 V.

P1AF5

The positive mid-pack voltage minus the high voltage is greater than 10 V.

DTCs P1AF4 and P1AF5 are Type B DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

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 .

WARNING

Ignition ON.
Verify DTC P1AF4 or P1AF5 is not set. If DTC P1AF4 or P1AF5 is set Replace the K59 starter/generator control module. If DTC P1AF4 and P1AF5 are not set
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for starter/generator control module replacement, programming, and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this repair.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The vehicle is equipped with a high voltage isolation monitor feature. The purpose of the isolation monitor is to test the resistance between the high voltage positive and negative direct current (DC) bus and chassis ground. The isolation monitoring system measures the resistance between the high voltage system and chassis ground in the following way. The starter/generator control module places an AC signal on the high voltage system and monitors its amplitude. A reduced amplitude return signal indicates a loss of resistance to chassis ground. This isolation monitor method is sometimes referred to as the active isolation monitor.

P1B0B

Power mode is RUN or CRANK.
Contactors are closed.

P1B0C

Power mode is RUN or CRANK.

P1B0B

The negative mid-pack voltage is less than 5 V.

P1B0OC

The negative mid-pack voltage minus the high voltage is greater than 10 V.

DTCs P1B0B and P1B0C are type B DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

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 .

WARNING

Ignition ON.
Verify P1B0B or P1B0C is not set. If P1B0B or P1B0C is set Replace the K59 starter/generator control module. If P1B0B and P1B0C are not set
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for starter/generator control module replacement, programming, and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The drive motor position sensor is monitored by the generator control module. The generator control module monitors the angular position, speed and direction of the starter generator based upon the signals of the resolver-type position sensor. The position sensor allows the drive motor control module to determine the exact position and speed of the starter generator.

The drive motor control module and hybrid powertrain control module are awake.

Starter generator speed is greater than 18, 000 RPM.

DTC P1B0D is a Type B DTC.
The hybrid powertrain control module opens the high voltage contactor relay.
The battery indicator light will illuminate.

DTC P1B0D is a Type B DTC.

Check for broken or missing drive belt.

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Verify if DTC P0A3F, P0A40, P1B03, P0C52, P0C53, P0C5C, and P0C5D are not set. If DTC P0A3F, P0A40, P1B03, P0C52, P0C53, P0C5C, and P0C5D is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
If the DTC is set, program the generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The vehicle is equipped with a high voltage isolation sensor rationality or performance fault detection. The purpose of the isolation voltage sensor monitor is to test the rationality between the sum of the high voltage positive and negative current sensed voltages against the high voltage sensed value and also against the high voltage value from the battery pack energy control module. This is part of the passive isolation monitor.

Main contactor is commanded closed.

All the following conditions exist

The mid-pack positive voltage minus the mid-pack negative voltage minus the high voltage battery voltage is greater than 15 V and he mid-pack positive voltage minus the mid-pack negative voltage minus the high voltage is greater than 10 V
The mid-pack positive voltage minus the mid-pack negative voltage minus the high voltage is greater than 10 V

DTC P1B41 is a type B DTC.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

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 .

WARNING

Ignition ON.
Verify P1B41 is not set. If P1B41 is set Replace the K59 starter/generator control module. If P1B41 is not set
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for starter/generator control module replacement, programming, and setup

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This is an internal fault detection of generator control module and no external circuits are involved.

The ignition voltage is greater than 9.5 V.

The difference between the redundant torque calculation and the primary calculation is greater than 36 N.m(27 lb ft).

DTC P1E0A is a Type A DTC.
The hybrid powertrain control module opens the high voltage contactor relay.

DTC P1E0A is a Type A DTC.

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Program the K59 starter generator control module. If the DTC resets replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The starter generator is also referred to as the drive motor. The drive motor temperature sensor is a variable resistor that measures the temperature of the drive motor stator windings. The hybrid powertrain control module supplies 5 V to the signal circuit and a ground for the low reference circuit. The hybrid powertrain control module calculates a value to estimate the drive motor rotor temperature. The hybrid powertrain control module uses the stator temperature, drive motor current, and commanded motor torque in order to calculate the value for the drive motor rotor temperature.

The drive motor control module and hybrid powertrain control module are awake.

DTCs P0A3F, P1A40, P1B03, P1B0D, P0C52, P0C53, P0C5C, P0C5D, P1AE8, P1AE9, P1AEC, P0BFD, P0BE6, P0BE7, P0BE8, P0BEE, P0BEF, and P0BF0 are not set.
The motor rotor temperature calculation is greater than 197°C (387°F) for 8 seconds and has not fallen below 194°C (381°F).

DTC P1E3B is a Type B DTC.
The hybrid powertrain control module system starts to reduce the maximum torque beginning at 180°C (356°F) down to 0 NM as the calculated drive motor rotor temperature approaches 200°C (392°F).

DTC P1E3B is a Type B DTC.

Ask about the customer's driving habits, trailer towing, etc.
Ensure the engine cooling system is functioning normally.
The drive motor stator temperature should be within 60°C (140°F) of the motor calculated rotor temperature.

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Check the cooling system for the correct amount of coolant. Refer to «Cooling System Draining and Filling (Static Fill)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) , «Cooling System Draining and Filling (GE 47716)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-ge) .
Verify that DTC P0A2C, P0CC1-P0CC4 is not set. If DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Start the engine and observe the scan tool motor A calculated rotor temperature parameter. The reading should be less than 180°C (356°F). If greater than the specified value, check the cooling system and pump for proper operation. If there is coolant and flow then monitor the calculated rotor temperature and verify that it drops below 180°C (356°F). If the temperature does not drop below 180°C (356°F) then reprogram the K59 starter generator control module. If the DTC resets, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The hybrid powertrain control module performs internal calculations multiple times and compares the results of these calculations to verify proper operation of the internal controller memory. The result of these calculations is a voltage value. This voltage value is an internal value and cannot be measured externally. This fault is handled inside the generator control module and no external circuits are involved.

The 12 V battery voltage is greater than 9 V.
The drive motor control module and the hybrid powertrain control module are awake.

If the results of these calculations differ by more than one volt.

DTC P1E3C is a type A DTC.
The high voltage contactor relay will be opened.

DTC P1E3C is a type A DTC.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Drive Motor Battery System Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-energy-storage-system__drive-motor-battery-system-description)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

If the DTC is set, replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Ignition Voltage	P2534	P2534	P2535

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Operating Conditions: Key ON Parameter Normal Range: 8-18 volts
IGN	0 volts	0 volts	B+

Ignition 1 Signal

The hybrid powertrain control module monitors the system voltage on the ignition voltage circuit.

The generator control module is communicating on the serial data circuits.

P2534

Ignition is ON.

P2535

Ignition is OFF.

P2535

The hybrid powertrain control module detects greater than 5 volts on the ignition voltage circuit at the generator control module when not enabled for greater than 10 seconds.

P2534

The hybrid powertrain control module detects less than 2 volts on the ignition voltage circuit at the generator control module for greater than 10 seconds.

DTCs P2534 and P2535 are Type A DTCs.

Verify the charging system is functioning correctly.
If the run crank circuit is shorted to voltage, the engine will continue to run with the ignition in the OFF position.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Ignition OFF, measure and record the battery voltage at the battery terminals. The battery voltage should stabilize between 12.4 and 12.8V within a few minutes of turning the ignition OFF. If not within the specified range, refer to «Battery Inspection/Test»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-hybrid-hp6) .
Ignition OFF, disconnect K59 starter generator control module X3 connector.
Ignition ON, test for 8-18V between the K59 starter generator control module X3 connector ignition voltage circuit terminal 10 and ground. If not within the specified range, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Starter Generator Control Module, also called the Starter generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Accessory Voltage	P2537	P2537

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Operating Conditions: Key ON Parameter Normal Range: Active
Accessory	Inactive	Inactive	Active

Ignition Input Accessory

The hybrid powertrain control module monitors the system voltage on the accessory voltage circuit.

The Ignition is ON.
The generator control module is communicating on the serial data circuits.

The generator control module detects less than 2 volts on the ignition voltage circuit at the generator control module for greater than 10 seconds.

P2537 is a Type C DTC.

Verify the charging system is functioning correctly.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)
«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)

Electrical Information Reference

«Circuit Testing»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Ignition OFF, disconnect K59 starter generator control module X2 connector.
Ignition ON, test for 8-18V between the K59 starter generator control module X2 connector accessory voltage circuit terminal 8 and ground. If not within the specified range, test the accessory voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal replace the K59 starter generator control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Starter Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Relay Switch B+	P2797 **	P2797
Relay Coil Ignition	P0B09 **	P0B09
Relay Coil Control	P0B09 *	P0B09	P0B09
Relay Switch Control	P2797 **	P2797	P2797 *
Component Ground		***
* Auxiliary Transmission Fluid Pump - always On The fuse opens * Auxiliary Transmission Fluid Pump - inoperative

The Ignition is ON.
The system voltage is between 9.0 and 32.0 V.

Condition 1

The vehicle is in autostop mode.

Condition 2

All conditions allowing an autostop have been met.
A/C compressor ON.

Condition 1

The calculated transmission slip speed is greater than 150 RPM during a vehicle launch from autostart mode, 7 consecutive times in the same key cycle.

Condition 2

The 14 volt power module output current does not increase by 100 watts or more when the auxiliary transmission fluid pump is commanded ON by the hybrid powertrain control module.

The 14 volt power module output current does not decrease by greater than 250 watts when the auxiliary transmission fluid pump is commanded OFF by the hybrid powertrain control module.

The hybrid powertrain control module disables the Autostop mode.
DTC P2797 is a Type B DTC.

DTC P2797 is a Type B DTC.

Driving a vehicle with an auxiliary transmission fluid pump failure that causes low or no pressure will cause a harsh transmission engagement on vehicle launch from an autostop.

Transmission Fluid Pump Relay Underhood Electrical Center Terminal Identification
Front of Vehicle
Left Side of Vehicle	Control	Load	Right Side of Vehicle
Left Side of Vehicle	B+	Ignition	Right Side of Vehicle

Schematic Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system)
«Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation)

DTC Type Reference

Verify that no other hybrid powertrain or transmission control module DTC is set. If any hybrid powertrain or transmission control module DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Perform the «Transmission Fluid Level and Condition Check»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-diagnostic-information-and-procedures__transmission-fluid-level-and-condition-check) to verify correct fluid level and condition.
Ignition ON.
Verify the auxiliary transmission fluid pump turns ON and OFF when commanding the auxiliary transmission fluid pump relay ON and OFF with a scan tool. If the pump does not operate Refer to Circuit/System Testing below. If the pump operates All OK. Refer to transmission «Line Pressure Check (Non Hybrid)»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-diagnostic-information-and-procedures__line-pressure-check-non-hybrid) , «Line Pressure Check (Hybrid)»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-diagnostic-information-and-procedures__line-pressure-check-hybrid) .

Ignition OFF, disconnect the KR86 transmission fluid pump relay - auxiliary, Ignition ON.
Verify a test lamp illuminates between the B+ circuit terminal 30 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Disconnect the X1 harness connector at the G5 Transmission Fluid Pump - Auxiliary, test for infinite resistance between the switched control circuit terminal 1 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the G5 Transmission Fluid Pump - Auxiliary. If the test lamp illuminates
Ignition OFF and all vehicle systems OFF, disconnect the X1 harness connector at the G5 Transmission Fluid Pump - Auxiliary. It may take up to 2 minutes for all vehicle systems to power down.
Test for less than 10 ohms between the G5 Transmission Fluid Pump - Auxiliary ground circuit X1 terminal 2 and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
Connect the harness connector at the G5 Transmission Fluid Pump - Auxiliary.
Connect a 30 A fused jumper wire between the B+ circuit terminal 30 and the switch control circuit terminal 87. Ignition ON.
Verify the G5 Transmission Fluid Pump - Auxiliary is ON. If the Pump is not ON Ignition OFF. Test for less than 2 ohms in the switch control circuit terminal 87 end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, test or replace the G5 Transmission Fluid Pump - Auxiliary. If the Pump is ON
Test or replace the KR86 Transmission Fluid Pump Relay - Auxiliary. If the DTC resets
Refer to transmission «Line Pressure Check (Non Hybrid)»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-diagnostic-information-and-procedures__line-pressure-check-non-hybrid) , «Line Pressure Check (Hybrid)»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-diagnostic-information-and-procedures__line-pressure-check-hybrid) .

Ignition OFF, disconnect the KR86 Transmission Fluid Pump Relay - Auxiliary.
Test for 85-130 ohms between terminals 85 and 86. If less than 85 ohms or greater than 130 ohms Replace the relay. If between 85-130 ohms
Test for infinite resistance between the terminals listed below: 30 and 86 30 and 87 30 and 85 85 and 87 If less than infinite resistance Replace the relay. If infinite resistance
Install a 3 A fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground.
Test for less than 2 ohms between terminals 30 and 87. If 2 ohms or greater Replace the relay. If less than 2 ohms
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

«Auxiliary Fluid Pump Removal (Hybrid)»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-repair-instructions-off-vehicle)
«Relay Replacement (Within an Electrical Center)»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions__relay-replacement-within-an-electrical-center) , «Relay Replacement (Attached to Wire Harness)»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , Within an Electrical Center, for Transmission Fluid Pump Relay - Auxiliary replacement.

Symptoms - Hybrid Controls

Note. The following steps must be completed before using the symptom tables.

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) before using the symptom tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data link.
Review the system operation in order to familiarize yourself with the system functions. Refer to the following procedures: «Generator Control Module Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system) «High Voltage Monitoring Systems Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__high-voltage-monitoring-systems-description) «Hybrid Modes of Operation Description»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system) «Starter Generator Description and Operation»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-description-and-operation) «Transmission General Description»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-description-and-operation__transmission-general-description)

Visual/Physical Inspection

Inspect for aftermarket devices which could affect the operation of the Hybrid System. Refer to «Checking Aftermarket Accessories»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .
Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

DC Power Conversion Test

Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The 14 volt power module supplies the energy that flows between the high voltage (115V) direct current (DC) and low voltage (14V) DC to charge the 12V battery and power accessories. The 14V power module receives a wake-up signal from the hybrid powertrain control module when the ignition is switched to On. After a successful initialization, the 14V power module receives an enable command from the hybrid powertrain control module to begin power conversion.

A poor connection at the B+ terminal of the 14V power module or open 300 Amp Mega-Fuse in the engine compartment, will prevent the 14V power module from operating.

Schematic Reference

Connector End View Reference