Battery, Charging System and Starting System Buick LaCrosse I

Fastener Tightening Specifications

Fastener Tightening Specifications

Battery Usage

Battery Usage

Generator Usage

Generator Usage

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Engine Electrical Connector End Views

Battery Current Sensor Connector Part Information OEM: 15326808 Service: 15306388 3-Way F GT 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A RD/WH 812 I/P Dimming Voltage Reference B BN 5077 Low Reference C WH 5075 Current Sensor Signal

Generator Connector Part Information OEM: 12186308 (Delphi) 1 928 403 137 (BOSCH) Service: 12186308 2-Way F JPT Sealed (BK) Pin Wire Color Circuit No. Function 1 RD 225 Generator Turn On Signal (L26) OG 225 Generator Turn On Signal (LY7) 2 GY 23 Generator Field Duty Cycle Signal

Hood Ajar Switch (AP3) Connector Part Information OEM: 15326801 Service: 15306156 2-Way F GT 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A PK/BK 109 Hood Ajar Switch Signal B BK 1350 Ground

Starter (LY7) Connector Part Information OEM: 12089916 Service: See Catalog 1-Way F Metri-Pack 280 Series (GY) Pin Wire Color Circuit No. Function A PU 6 Starter Solenoid Crank Voltage

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Engine Electrical

Begin the system diagnosis with Diagnostic System Check - Vehicle in Vehicle DTC Information. The Diagnostic System Check - Vehicle will provide the following information

1. The identification of the control modules which command the system
2. The ability of the control modules to communicate through the serial data circuit
3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check - Vehicle will identify the correct procedure for diagnosing the system and where the procedure is located.

Scan Tool Output Controls

ECM

IPC

Scan Tool Data List

Body Control Module (BCM)

Instrument Panel Cluster (IPC)

Powertrain Control Module (PCM)

Engine Control Module (ECM)

Circuit Description

The body control module (BCM) has an internal voltage sensor with a dedicated circuit that measures the battery voltage to determine if it is above 9 volts.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC B1327 Device Power 1 Circuit Low

Conditions for Running the DTC

This DTC shall run only if the BCM has power, ground and the ignition is not in START mode. This DTC shall execute regardless of the battery voltage.

Conditions for Setting the DTC

1. This DTC shall be set as current when the voltage falls below 9 volts for 1,200 milliseconds.
2. When the vehicle exits START, the BCM shall delay checking the voltage for 2 seconds.

Action Taken When the DTC Sets

1. The BCM will not illuminate the charge indicator.
2. A message shall be sent out to notify all other modules of low battery voltage.

Conditions for Clearing the MIL/DTC

In order to clear the DTC from a current status the ignition must be cycled and the voltage shall be greater than 9 volts.

Test Description

The number below refers to the step number on the diagnostic table.

1. 3: This step compares battery voltage with the voltage that the BCM calculates.

DTC B1327

The body control module (BCM) has an internal voltage sensor with a dedicated circuit that checks the battery positive voltage and battery negative circuit voltage to determine if it is below 15.5 volts.

This diagnostic procedure supports the following DTC

DTC B1328 Device Power 1 Circuit High

This DTC shall run only if the BCM has power, ground and the ignition is not in START mode. This DTC shall execute regardless of the battery voltage.

This DTC shall be set as current when the voltage raises above 15.5 volts for 1,200 milliseconds.

1. The engine control module (ECM) will not illuminate the charge indicator.
2. This DTC shall be set as current when the voltage raises above 17 volts for 1,200 milliseconds.
3. A message shall be sent out on the class 2 lines to notify all other modules of low battery voltage.

In order to clear the DTC from a current status, the ignition must be cycled and the voltage shall be less than 17 volts.

The number below refers to the step number on the diagnostic table.

1. 3: This step compares battery voltage with the voltage that the BCM calculates.

DTC B1328

The battery current sensor pulse width modulation (PWM) input signal is monitored by the body control module (BCM) which sends a serial data message to the engine control module (ECM)/powertrain control module (PCM) when the PWM input signal is out of the normal operating range.

This diagnostic procedure supports the following DTC

DTC B1516 Battery Current Sensor Performance

1. The key is in the ON position.
2. The engine is running.

This DTC will be set as current when the duty cycle of the PWM input signal is less than 2 percent or more than 98 percent for more than 90 seconds.

The SERVICE VEHICLE SOON warning message will be set in the driver information center (DIC).

The DTC clears as a current status when the battery sensed current returns to normal range for more than 15 seconds.

DTC B1516

The powertrain control module (PCM) monitors the system voltage to make sure that the voltage stays within the proper range. Damage to components and incorrect data input can occur when the voltage is out of range. The PCM monitors the system voltage over an extended length of time. If the PCM detects a system voltage outside an expected range for the calibrated length of time, DTC P0560 will set.

This diagnostic procedure supports the following DTC

DTC P0560 System Voltage

1. System voltage below 11 volts
2. Engine speed above 1,500 RPM
3. Vehicle speed below 40 km/h (25 mph)

The PCM detects a system voltage out of range for 2 seconds.

1. The PCM will not illuminate the malfunction indicator lamp (MIL).
2. The PCM will command a message to be displayed.
3. The PCM will store conditions which were present when the DTC set as Failure Records data only.

Conditions for Clearing the DTC

1. The PCM will command the message OFF after one trip in which the diagnostic test has been run and passed.
2. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
3. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P0560

The engine control module (ECM) checks the system voltage to make sure that the voltage stays within the proper range. Damage to components and incorrect input can occur when the voltage is out of range. The ECM monitors the system voltage over an extended length of time. If the ECM detects an excessively low system voltage, DTC P0562 will set.

This diagnostic procedure supports the following DTC

DTC P0562 System Voltage Low

1. Engine speed above 1,500 RPM
2. System voltage between 9.5-18 volts

The ECM detects a system voltage below 10 volts for 5 seconds.

1. The ECM will command a message to be displayed.
2. The ECM will not illuminate the malfunction indicator lamp (MIL).
3. The ECM will store conditions which were present when the DTC set as Failure Records data only.

1. The ECM will command the message OFF after one trip in which the diagnostic test has been run and passed.
2. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
3. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P0562

The engine control module (ECM) checks the system voltage to make sure that the voltage stays within the proper range. Damage to components and incorrect input can occur when the voltage is out of range. The ECM monitors the system voltage over an extended length of time. If the ECM detects an excessively high system voltage, DTC P0563 will set.

This diagnostic procedure supports the following DTC

DTC P0563 System Voltage High

1. Engine speed above 1,500 RPM
2. System voltage between 9.5-18 volts

The ECM detects a system voltage above 16 volts for less than 1 second.

1. The ECM will command a message to be displayed.
2. The ECM will not illuminate the malfunction indicator lamp (MIL).
3. The ECM will store conditions which were present when the DTC set as Failure Records data only.

1. The ECM will command the message OFF after one trip in which the diagnostic test has been run and passed.
2. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
3. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P0563

The powertrain control module (PCM) supplies a ground path for the crank relay when start enable has been requested. The PCM monitors this circuit for conditions that are incorrect for the commanded state. If the PCM detects an improper circuit condition, starter relay DTC P0615 will set.

This diagnostic procedure supports the following DTC

DTC P0615 Starter Relay Control Circuit

System voltage is between 9-16 volts.

1. The PCM detects an improper voltage level on the output circuit that controls the starter relay.
2. The condition exists for at least 2 seconds.

1. The PCM will not illuminate the malfunction indicator lamp (MIL)
2. The PCM will store the conditions present when the DTC set as Failure Records data only.

1. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
2. The DTC can be cleared by using the scan tool Clear DTC Information function.

Diagnostic Aids

Ignition system DTCs set with the ignition switch in the START position if the starter relay or the starter is inoperative. When the PCM enables starter operation, the PCM also initiates the diagnostic test routines for DTCs P0335, P0340 and P0385. If a condition exists which prevents the engine from cranking, the PCM will not receive signal input from the crankshaft position (CKP) and camshaft position (CMP) sensors and the DTCs will set.

Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may assist in diagnosing the condition. The information may help determine how often the condition that set the DTC occurs.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: Listen for an audible click when the crank relay operates. Turn the ignition switch back and forth from the ON to START positions. Repeat this as necessary.
2. 3: This step tests for voltage at the coil side of the crank relay. The PCM IGN fuse supplies power to the coil side of the crank relay.
3. 4: This step verifies that the PCM is providing ground to the crank relay.
4. 5: This step tests if ground is constantly being applied to the crank relay.

DTC P0615

The engine control module (ECM) supplies a ground path for the starter relay when start enable has been requested. The ECM monitors this circuit for conditions that are incorrect for the commanded state. If the ECM detects an improper circuit condition, starter relay DTC P0616 will set.

This diagnostic procedure supports the following DTC

DTC P0616 Starter Relay Control Circuit Low Voltage

1. System voltage is between 8-16 volts.
2. The engine is running.

1. The ECM detects an improper voltage level on the output circuit that controls the starter relay.
2. The condition exists for at least 2 seconds.

1. The ECM will not illuminate the malfunction indicator lamp (MIL).
2. The ECM will store the conditions present when the DTC set as Failure Records data only.

1. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
2. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P0616

The engine control module (ECM) supplies a ground path for the starter relay when start enable has been requested. The ECM monitors this circuit for conditions that are incorrect for the commanded state. If the ECM detects an improper circuit condition, starter relay DTC P0617 will set.

This diagnostic procedure supports the following DTC

DTC P0617 Starter Relay Control Circuit High Voltage

1. System voltage is between 8-16 volts.
2. The engine is running.

1. The ECM detects an improper voltage level on the output circuit that controls the starter relay.
2. The condition exists for at least 2 seconds.

1. The ECM will not illuminate the malfunction indicator lamp (MIL).
2. The ECM will store the conditions present when the DTC set as Failure Records data only.

1. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
2. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P0617

The powertrain control module (PCM) uses the generator turn on signal circuit to control the load of the generator on the engine. A high side driver in the PCM applies a voltage to the voltage regulator. This signals the voltage regulator to turn the field circuit ON and OFF. When the PCM turns ON the high side driver, the voltage regulator turns ON the field circuit. When the PCM turns OFF the high side driver, the voltage regulator turns OFF the field circuit.

The PCM monitors the state of the generator turn on signal circuit. The PCM should detect a low generator turn on signal circuit voltage when the key is ON and the engine is OFF or when the charging system malfunctions. With the engine running, the PCM should detect a high generator turn on signal circuit. The PCM performs key ON and RUN tests to determine the status of the generator turn on signal circuit. During the key ON test, if the PCM detects a high generator turn on signal circuit voltage, DTC P0621 will set. DTC P0621 will also set if, during the RUN test, the PCM detects a low generator turn on signal circuit. When the DTC sets, the PCM will send a class 2 serial data message to the instrument panel cluster (IPC) to illuminate the charge indicator.

This diagnostic procedure supports the following DTC

DTC P0621 Generator L-Terminal Circuit

Key ON Test

1. No generator, crankshaft position (CKP) sensors or camshaft position (CMP) sensor DTCs are set.
2. The key is in the RUN position.
3. The engine is not running.

Run Test

1. No generator, CKP sensors or CMP sensor DTCs are set.
2. The engine is running.

1. During the key ON test, the PCM detects a high signal voltage on the generator turn on signal circuit for at least 5 seconds. OR
2. During the RUN test, the PCM detects a low signal voltage on the generator turn on signal circuit for at least 15 seconds.

1. The PCM will not illuminate the malfunction indicator lamp (MIL).
2. The PCM will store the conditions present when the DTC set as Failure Records data only.

1. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
2. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P0621

The powertrain control module (PCM) uses the generator field duty cycle signal circuit to monitor the duty cycle of the generator. The generator field duty cycle signal circuit connects to the high side of the field winding in the generator. A pulse width modulated (PWM) high side driver in the voltage regulator turns the field winding ON and OFF. The PCM uses the PWM signal input to determine the generator load on the engine. This allows the PCM to adjust the idle speed to compensate for high electrical loads.

The PCM monitors the state of the generator field duty cycle signal circuit. When the key is in the RUN position and the engine is OFF, the PCM should detect a duty cycle near 0 percent. However, when the engine is running, the duty cycle should be between 5 percent and 100 percent. The PCM monitors the PWM signal using a key ON test and a RUN test. During the tests, if the PCM detects an out of range PWM signal, DTC P0622 will set. When the DTC sets, the PCM will send a class 2 serial data message to the instrument panel cluster (IPC) to illuminate the charge indicator.

This diagnostic procedure supports the following DTC

DTC P0622 Generator F-Terminal Circuit

Key ON Test

1. No generator, crankshaft position (CKP) sensors or camshaft position (CMP) sensor DTCs are set.
2. The key is in the RUN position.
3. The engine is not running.

Run Test

1. No generator, CKP sensors or CMP sensor DTCs are set.
2. The engine is less than 3,000 RPM.

1. During the ignition ON test, the PCM detects a PWM signal is out of range.
2. During the RUN test, the PCM detects a PWM signal less then 5 percent for more than 6 seconds.

1. The PCM will store the conditions present when the DTC set as Fail Records data only.
2. The malfunction indicator lamp (MIL) will not illuminate.

1. The Conditions for Setting the DTC are no longer present.
2. A history DTC will clear after 40 malfunction free ignition cycles.
3. The PCM receives the clear code command from the scan tool.

DTC P0622

The engine control module (ECM) uses the generator field duty cycle signal circuit to monitor the duty cycle of the generator and fault indication. The generator field duty cycle signal circuit connects to the high side of the field winding in the generator. A pulse width modulated (PWM) high side driver in the voltage regulator turns the field winding ON and OFF. The ECM uses the PWM signal input to determine the generator load on the engine. This allows the ECM to adjust the idle speed to compensate for high electrical loads.

The ECM monitors the state of the generator field duty cycle signal circuit. When the engine is running, the ECM should detect a duty cycle that varies up to 100 percent. The ECM monitors the PWM signal using a key ON test and a RUN test. During the tests, if the ECM detects an out of range PWM signal, a DTC will set. When the DTC sets, the ECM will send a class 2 serial data message to the instrument panel cluster (IPC) and driver information center (DIC) to illuminate the charge indicator or display a charging message.

This diagnostic procedure supports the following DTC

DTC P0625 Generator F-Terminal Circuit Low Voltage

1. No generator, crankshaft position (CKP) sensors or camshaft position (CMP) sensor DTCs are set.
2. The engine is less than 3,000 RPM.
3. The generator has not been commanded OFF by the ECM or scan tool.

The ECM detects a PWM signal less than 5 percent for at least 15 seconds.

1. The ECM will not illuminate the malfunction indicator lamp (MIL).
2. The ECM will store the conditions present when the DTC set as Failure Records data only.
3. The ECM will send a class 2 serial data message to the IPC and DIC to illuminate the charge indicator or display a charging message.

1. The conditions for setting DTC P0625 are not present.
2. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P0625

The engine control module (ECM) uses the generator field duty cycle signal circuit to monitor the duty cycle of the generator and fault indication. The generator field duty cycle signal circuit connects to the high side of the field winding in the generator. A pulse width modulated (PWM) high side driver in the voltage regulator turns the field winding ON and OFF. The ECM uses the PWM signal input to determine the generator load on the engine. This allows the ECM to adjust the idle speed to compensate for high electrical loads.

The ECM monitors the state of the generator field duty cycle signal circuit. When the key in the ON position, with the engine OFF, the ECM should detect a duty cycle that is 0 percent.

The ECM monitors the PWM signal using a key ON test and a RUN test. During the tests, if the ECM detects an out of range PWM signal, a DTC will set.

This diagnostic procedure supports the following DTC

DTC P0626 Generator F-Terminal Circuit High Voltage

1. No generator, crankshaft position (CKP) sensors or camshaft position (CMP) sensor DTCs are set.
2. The engine is not running.
3. The key is in the ON position.

The ECM detects a PWM signal greater than 5 percent for at least 15 seconds.

1. The ECM will not illuminate the malfunction indicator lamp (MIL).
2. The ECM will store the conditions present when the DTC set as Failure Records data only.
3. The ECM will send a class 2 serial data message to the instrument panel cluster (IPC) and driver information center (DIC) to illuminate the charge indicator or display a charging message.

1. The conditions for setting DTC P0626 are not present.
2. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P0626

The engine control module (ECM) uses the generator turn-on signal circuit to control the voltage output of the generator. When a different voltage is desired, the ECM will change the pulse width modulation (PWM) signal to the voltage regulator via the generator turn-on signal circuit. This causes the voltage regulator to the voltage output of the generator. The ECM has fault detection circuitry which monitors the state of the generator turn-on signal circuit. If the fault detection circuit senses a voltage other than what is expected, this DTC will set. The voltage regulator also contains fault detection circuitry. If the regulator detects a problem, the regulator will ground the generator turn-on signal circuit, pulling the voltage low. This also causes the ECM to set the DTC.

This diagnostic procedure supports the following DTC

DTC P1668 Generator L-Terminal Control Circuit

Key ON Test

1. The key is in the ON position for 5 seconds.
2. The engine is OFF.

Engine Run Test

1. The engine is running.
2. The engine speed is less than 3,000 RPM.

Key ON Test

1. The ECM detects a high signal voltage on the generator turn on signal circuit for at least 5 seconds.
2. The engine must be started.

During the RUN test, the ECM detects a low signal voltage on the generator turn on signal circuit for at least 5 seconds.

1. The ECM sends a class 2 message to the instrument panel cluster (IPC) to illuminate the charge indicator and/or turn on a message.
2. The ECM will not illuminate the malfunction indicator lamp (MIL).
3. The ECM will store the conditions present when the DTC set as Failure Records data only.

1. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
2. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P1668

Symptoms - Engine Electrical

1. Perform «Control Module References»(/buick/lacrosse/i-2004-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) 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.
2. Review the system descriptions and operations in order to familiarize yourself with the system functions. Refer to one of the following system operations: «Battery Description and Operation (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__battery-description-and-operation-ly7) «Battery Description and Operation (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__battery-description-and-operation-l26) «Starting System Description and Operation»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__starting-system-description-and-operation) «Charging System Description and Operation»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) «Load Shed System Description and Operation»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system)

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the starting and charging systems. Refer to «Checking Aftermarket Accessories»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__checking-aftermarket-accessories) .
2. 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

1. «Battery Inspection/Test»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system)
2. «Battery Electrical Drain/Parasitic Load Test»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system)
3. «Battery Common Causes of Failure»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__battery-common-causes-of-failure)
4. «Charging System Test»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__charging-system-test)
5. «Charge Indicator Always On»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__charge-indicator-always-on)
6. «Charge Indicator Inoperative»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__charge-indicator-inoperative)
7. «Generator Noise Diagnosis»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system)
8. «Starter Solenoid Does Not Click»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__starter-solenoid-does-not-click)
9. «Starter Solenoid Clicks, Engine Does Not Crank»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__starter-solenoid-clicks-engine-does-not)
10. «Engine Cranks Slowly»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__engine-cranks-slowly)
11. «Starter Motor Noise Diagnosis»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system)

Tools Required

J 42000 Battery Tester. See Special Tools .

Follow these instructions in order to avoid an incorrect diagnosis because of connections

1. If testing the vehicle with the battery cables still connected, wiggle the J 42000 clips on the terminal bolt. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) . This may cut through any coating or through any oxidation that may be present on the bolt. Even new bolts contain a protective coating that may insulate or cause a resistance in the test circuit.
2. If correct connections to the battery terminal bolts in the vehicle are in doubt, perform the following steps: Disconnect the negative battery cable. Disconnect the positive battery cable. Install the test adapters on the terminals. Follow the instructions for an Out-of-Vehicle test.
3. If the tester displays a REPLACE BATTERY or BAD CELL-REPLACE result for a battery tested in the vehicle with the battery cables connected, perform the following steps: Disconnect the negative battery cable. Disconnect the positive battery cable. Install the tester adapters. Follow the instructions for an Out-of-Vehicle test. Replace the battery only if the Out-of-Vehicle test shows a REPLACE BATTERY or BAD CELL-REPLACE result. This prevents battery replacements that are due only to faulty battery cable connections.
4. Use the correct terminal adapters. Do not use any common bolts or a combination of bolts, nuts and or washers as adapters when testing the battery. Use the test adapters that are provided with the J 42000 or P/N 12303040 terminal adapters. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) . If the adapters that are provided with the J 42000 require replacement, use P/N 12303040. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) . Any other adapter may not contact the correct areas of the battery terminal, causing a resistance that may result in an invalid battery test result.

Battery Inspection/Test

AGM Battery State of Charge

The AGM maintenance free battery's state of charge (SOC) is estimated by reading the voltage of the battery. Because the voltage is affected by current flow into or out of the battery, the engine must be stopped and all electrical loads turned off when checking the voltage. The voltage can also be affected if the battery has just been charged or discharged, so it is important to consider what has happened to the battery in the time just before testing. Use the following procedure to determine the battery's state of charge

1. Be sure all electrical loads are turned off.
2. Determine whether the battery has been used in a vehicle or charged within the past 12 hours. If the answer is no, the terminal voltage will be stabilized and no action is necessary before reading the voltage. Skip to Step 3. If the answer is yes, remove any surface charge with a carbon pile tester as follows: Turn the carbon pile tester load completely OFF. Connect the carbon pile tester across the battery terminals. Discharge the battery at 300 amperes for 15 seconds. Turn the carbon pile tester load completely OFF. Disconnect the carbon pile tester from the battery terminals. Wait for at least 15 seconds for the battery to recover.
3. Estimate the battery temperature by determining the average temperature to which the battery has been exposed for the past 12 hours.
4. Measure the battery voltage at the battery terminals. Refer to the following table to determine the state of charge according to the estimated battery temperature

Battery Charging (LY7)

Use the state of charge information as follows

1. A battery with a SOC that is below 65 percent must always be recharged before returning it to service or continuing storage.
2. A battery with a SOC that is 65 percent or greater is generally considered to be charged enough in order to be returned to normal service or in order to continue storage. However, if the battery is being used in slow traffic or with short drive times or if the temperature is very hot or very cold, the battery should be fully charged (to at least 90 percent) before returning it to service or continuing storage.

1. For best results, use an automatic taper-rate battery charger with a voltage capability of 16 volts.
2. The charging area should be well ventilated.
3. Do not charge a battery that appears to be frozen; allow the battery to warm to room temperature and test it before charging.

Charging Time Required

The time required to charge a battery will vary depending upon the following factors

1. The battery charger capacity. The higher the charger's amperage, the less time it will take to charge the battery.
2. The SOC of the battery. A completely discharged battery requires more than twice as much charging time as a half charged battery. In a discharged battery with a voltage below 11 volts, the battery has a very high internal resistance and may only accept a very low current at first. Later, as the charging current causes the acid content to increase in the electrolyte, the charging current will increase. Extremely discharged batteries may not activate the reversed voltage protection in some chargers. Refer to the manufacturers instructions for operating this circuitry.
3. The temperature of the battery. The colder the battery is, the more time it takes to recharge the battery. The charging current accepted by a cold battery is very low at first; then, as the battery warms, the charging current will increase.

Charging Procedure

Note. Turn OFF the ignition when connecting or disconnecting the battery cables, the battery charger or the jumper cables. Failure to do so may damage the PCM or other electronic components.

Note. Turn OFF the ignition when connecting or disconnecting the battery cables. Failure to do so may damage the engine control module (ECM) or other electronic components.

When charging side-terminal batteries with the battery cables connected, connect the charger to the positive cable bolt and to a ground located away from the battery. When charging side-terminal batteries with the battery cables disconnected, install the battery side terminal adapters and connect the charger to the adapters.

Tighten: Tighten the battery side terminal adapters to 15 N.m (11 lb ft).

Use the following procedure to charge the battery

1. Turn OFF the charger.
2. Ensure that all of the battery terminal connections are clean and tight.
3. Connect the charger positive lead to the battery positive terminal. NOTE: Do not connect the negative charger lead to the housings of other vehicle electrical accessories or equipment. The action of the battery charger may damage such equipment.
4. Connect the negative charger lead to a solid engine ground or to a ground stud in the engine compartment that is connected directly to the battery negative terminal, but away from the battery. If the negative battery cable is disconnected and a terminal adapter is being used, connect directly to the adapter.
5. Turn ON the charger and set to the highest setting for normal charging.
6. After charging, test the battery. Refer to «Battery Inspection/Test»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

J 42000 Battery Tester. See Special Tools .

1. For best results, use an automatic taper-rate battery charger with a voltage capability of 16 volts.
2. The charging area should be well ventilated.
3. Do not charge a battery that appears to be frozen. Allow the battery to warm to room temperature and test it using the J 42000 before charging. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .

Battery State of Charge

The maintenance-free battery's SOC is estimated by reading the voltage of the battery across the battery terminals. Because the voltage is affected by current flow into or out of the battery, the engine must be stopped and all electrical loads turned OFF, including parasitic loads, when checking the voltage. The voltage can also be affected if the battery has just been charged or discharged, so it is important to consider what has happened to the battery in the time just before testing. Use the following procedure to determine the battery's SOC

1. Be sure all electrical loads are turned OFF.
2. Determine whether the battery has been used in a vehicle or charged within the past 12 hours. If the answer is no, the terminal voltage will be stabilized and no action is necessary before reading the voltage. Skip to step 3. If the answer is yes, terminal voltage will not be stabilized and you should wait 12 hours since the last time the battery was used.
3. Estimate the battery temperature by determining the average temperature to which the battery has been exposed for the past 12 hours.
4. Measure the battery voltage at the battery terminals. Refer to «Battery Charging (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) to determine the SOC according to the estimated battery temperature

Battery Charging (L26)

Use the SOC information as follows

1. A battery with a SOC that is below 65 percent must always be recharged before returning it to service or continuing storage.
2. A battery with a SOC that is 65 percent or greater is generally considered to be charged enough in order to be returned to normal service or in order to continue storage. However, if the battery is being used in slow traffic or with short drive times or if the temperature is very hot or very cold, the battery should be fully charged, to at least 90 percent, before returning it to service or continuing storage.

The time required to charge a battery will vary depending upon the following factors

1. The battery charger capacity. The higher the charger amperage, the less time it will take to charge the battery.
2. The SOC of the battery. A completely discharged battery requires more than twice as much charging time as a half charged battery. In a discharged battery with a voltage below 11 volts, the battery has a very high internal resistance and may only accept a very low current at first. Later, as the charging current causes the acid content to increase in the electrolyte, the charging current will increase. Extremely discharged batteries may not activate the reversed voltage protection in some chargers. Refer to the manufacturer's instructions for operating this circuitry.
3. The temperature of the battery. The colder the battery is, the more time it takes to recharge the battery. The charging current accepted by a cold battery is very low at first. As the battery warms, the charging current will increase.

Note. Turn OFF the ignition when connecting or disconnecting the battery cables, the battery charger or the jumper cables. Failure to do so may damage the powertrain control module (PCM) or other electronic components.

Note. Refer to FASTENER NOTICE .

When charging side-terminal batteries with the battery cables connected, connect the charger to the positive cable bolt and to a ground located away from the battery. When charging side-terminal batteries with the battery cables disconnected, install the battery side terminal adapters and connect the charger to the adapters.

Tighten: Tighten the battery side terminal adapters to 15 N.m (11 lb ft).

Use the following procedure to charge the battery

1. Turn OFF the charger.
2. Ensure that all of the battery terminal connections are clean and tight.
3. Connect the charger positive lead to the battery positive terminal on the battery or the remote jumper stud underhood.
4. Connect the negative charger lead to a solid engine ground or to a ground stud in the engine compartment that is connected directly to the battery negative terminal, but away from the battery. If the negative battery cable is disconnected and a terminal adapter is being used, connect directly to the adapter.
5. Turn ON the charger and set to the highest setting for normal charging.
6. Inspect the battery every half hour after starting the battery charger. Charge the battery until the taper-rate charger indicates that the battery is fully charged. Estimate the battery temperature by feeling the side of the battery. If it feels hot to the touch or its temperature is over 45°C (125°F), discontinue charging and allow the battery to cool before resuming charging.
7. After charging, test the battery. Refer to «Battery Inspection/Test»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

J 38758 Parasitic Draw Test Switch. See Special Tools .

1. Be sure to rule out any possible obvious influences, such as customer error or aftermarket equipment.
2. Customer driving habits, such as regular short trips. This does not allow enough time to properly charge the battery. Refer to «Battery Description and Operation (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__battery-description-and-operation-ly7) or «Battery Description and Operation (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__battery-description-and-operation-l26) .
3. Verify that the battery and charging system are in proper working order. Refer to «Battery Charging (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Charging (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) and «Charging System Test»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__charging-system-test) .
4. A battery discharging for no apparent reason while the vehicle is parked can be caused by an intermittent draw, such as a module waking up or a continuous draw, such as a dome light or stuck relay.
5. Some systems and modules such as OnStar® and regulated voltage control (RVC), if equipped, are designed to wake-up, perform a task and go back asleep at regular intervals. Refer to «Body Control System Description and Operation»(/buick/lacrosse/i-2004-2009/remont/communication-devices/#computerintegrating-systems__body-control-system-description-and-operation) for the system or modules description and operation.
6. Remote keyless entry (RKE) will wake up due to an outside input. Refer to «Keyless Entry System Description and Operation»(/buick/lacrosse/i-2004-2009/remont/door-locks-anti-theft-systems/#keyless-entry-system) for the system description and operation.
7. The battery run down time will vary depending on cold cranking amperage (CCA) and reserve capacity (RC). If the CCA and RC are higher, then the battery run down time would be longer. If the CCA and RC are lower, then the battery run down time would be shorter. The graph below indicates roughly how many days a 690 CCA battery with at 110 min. RC (60.5 AH) starting at 80 percent state of charge will last with a constant current draw until it reaches 50 percent state of charge. Differences in battery rating and temperature will affect the results.

Battery Electrical Drain/Parasitic Load Test

Load Test

Note. Do not turn the parasitic draw test switch to the OFF position with the engine running. Damage will occur to the vehicle's electrical system.

Note. The test switch must be in the ON position when removing the fuses in order to maintain continuity in the electrical system. This avoids damaging the digital multimeter due to accidental overloading, such as a door being opened to change a fuse.

1. Disconnect the battery negative cable from the battery negative terminal.
2. Install the male end of the J 38758 to the battery ground terminal. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .
3. Turn the J 38758 knob to the OFF position. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .
4. Install the battery negative cable to the female end of the J 38758 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .
5. Turn the J 38758 knob to the ON position. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .
6. Road test the vehicle and activate ALL of the accessories, including the radio and air conditioning. This may take up to 30 minutes.
7. Park the vehicle. Turn the ignition switch to the OFF position and remove the ignition switch key.
8. Connect a 10A fused jumper wire to the test switch tool terminals.
9. Turn the J 38758 knob to the OFF position. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) . The current now flows through the jumper wire.
10. Wait 1 minute. If the fuse blows, install an inductive ammeter and go to step 20.
11. Remove the fused jumper wire.
12. Set a digital multimeter to the 10A scale.
13. Connect the digital multimeter to the test switch tool terminals.
14. Turn the J 38758 knob to the OFF position. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) . The current flows now through the digital multimeter.
15. Wait 1 minute. Check and record the current reading. When there is a current reading on 2A or less, turn the J 38758 knob to the ON position. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) . The electrical current will now pass through the switch. Then switch the digital multimeter down to the 2A scale for a more accurate reading when the J 38758 knob is turned OFF. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .
16. Turn the J 38758 knob to the OFF position. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) . Wait 15 minutes for most vehicles.
17. Check and record the current reading.
18. Note the battery reserve capacity, amp hour rating. Refer to «Battery Usage»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__battery-usage) . Divide the reserve capacity by 4, amp hour rating by 2.4. Compare this to the multimeter milliampere reading taken in the previous step. The parasitic current drain should not exceed this number. Example: If a battery has a reserve capacity of 100 minutes, (60 A/H) the current drain should not exceed 25 mA.
19. If excessive current drain is not found at this time and there are no other apparent causes, complete the following: Using the MIN/MAX function of the digital multimeter, monitor the parasitic drain overnight or during the day. This will determine if something has been activated during that time frame. NOTE: The test switch must be in the ON position when removing the fuses in order to maintain continuity in the electrical system. This avoids damaging the digital multimeter due to accidental overloading, such as a door being opened to change a fuse. IMPORTANT: Removing fuses, relays and connectors to determine the failure area may wake up modules. You must wait for these modules to go to sleep or use the sleep function on the scan tool. When the vehicle has an unacceptable amount of parasitic current drain, remove each fuse one at a time until the current drain falls to an acceptable level. This will indicate which circuit is causing the drain. Refer to «Power Distribution Schematics»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing) to diagnose exactly which part of the suspect circuit is causing the parasitic drain. In some cases a non-fused circuit or component, such as a relay, is the cause of excessive parasitic current drain. Repeat the parasitic current drain test procedure after any repair has been completed to make sure that the parasitic current drain is at an acceptable level. When the cause of the excessive current drain has been located and repaired, remove the J 38758 . See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .
20. Connect the battery negative cable to the battery negative terminal.

Battery Common Causes of Failure

A battery is not designed to last forever. With proper care, however, the battery will provide years of good service. If the battery tests good but still fails to perform well, the following are some of the more common causes

1. A vehicle accessory was left on overnight.
2. The driving speeds have been slow with frequent stops, stop-and-go driving, with many electrical accessories in use, particularly air conditioning, headlights, wipers, heated rear window, cellular telephone, etc.
3. The electrical load has exceeded the generator output, particularly with the addition of aftermarket equipment.
4. Existing conditions in the charging system, including the following possibilities: A slipping belt A bad generator
5. The battery has not been properly maintained, including a loose battery hold down or missing battery insulator if used.
6. There are mechanical conditions in the electrical system, such as a short or a pinched wire, attributing to power failure. Refer to «General Electrical Diagnosis Procedures»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing) in Wiring Systems.

Electrolyte Freezing

The freezing point of electrolyte depends on its specific gravity. A fully charged battery will not freeze until the ambient temperature gets below -54°C (-65°F). However, a battery with a low state of charge may freeze at temperatures as high as -7°C (20°F). Since freezing may ruin a battery, the battery should be protected against freezing by keeping it properly charged. As long as the green eye is visible in the hydrometer, the freezing point of the battery will be somewhere below -32°C (-25°F).

Battery Protection During Vehicle Storage

Certain devices on the vehicle maintain a small continuous current drain, parasitic load, on the battery. A battery that is not used for an extended period of time will discharge. Eventually permanent damage will result. Discharged batteries will also freeze in cold weather. Refer to Battery Inspection/Test .

In order to maintain the battery state of charge while storing the vehicle for more than 30 days

1. Ensure that the green dot is visible in the built-in hydrometer.
2. Disconnect the battery ground cable to protect the battery from discharge by parasitic current drains.

When the battery cannot be disconnected

1. Maintain a high state of charge.
2. Establish a regular schedule for recharging the battery every 20-45 days.

A battery that has remained in a discharged state for a long period of time is difficult to recharge or may be permanently damaged.

Jump Starting in Case of Emergency

Note. This vehicle has a 12 volt, negative ground electrical system. Make sure the vehicle or equipment being used to jump start the engine is also 12 volt, negative ground. Use of any other type of system will damage the vehicle's electrical components.

1. Position the vehicle with the booster battery so that the jumper cables will reach. Do not let the 2 vehicles touch. Make sure that the jumper cables do not have loose ends or missing insulation.
2. Place an automatic transmission in PARK. If equipped with a manual transmission, place in NEUTRAL and block the wheels.
3. Turn OFF all electrical loads on both vehicles that are not needed.
4. Turn OFF the ignition on both vehicles.
5. Connect the red positive (+) cable to the battery positive (+) terminal (2) of the vehicle with the discharged battery. Use a remote positive (+) terminal if the vehicle has one.
6. Connect the red positive (+) cable to the positive (+) terminal (1) of the booster battery. Use a remote positive (+) terminal if the vehicle has one.
7. Connect the black negative (-) cable to the negative (-) terminal (3) of the booster battery.
8. The final connection is made to a heavy, unpainted metal engine part (4) of the vehicle with the discharged battery. This final attachment must be at least 46 cm (18 in) away from the dead battery.
9. Start the engine of the vehicle that is providing the boost.
10. Crank the engine of the vehicle with the discharged battery.
11. The black negative (-) cable must be first disconnected from the vehicle that was boosted (4).
12. Disconnect the black negative (-) cable from the negative (-) terminal (3) of the booster battery.
13. Disconnect the red positive (+) cable from the positive (+) terminal (1) of the booster battery.
14. Disconnect the red positive (+) cable from the remote positive (+) terminal (2) of the vehicle with the discharged battery.

Charging System Test

Charging System Test

Charge Indicator Always On

Charge Indicator Always On

Charge Indicator Inoperative

Charge Indicator Inoperative

Noise from a generator may be due to electrical or mechanical noise. Electrical noise or magnetic whine usually varies with the electrical load placed on the generator and is a normal operating characteristic of all generators. When diagnosing a noisy generator, it is important to remember that loose or misaligned components around the generator may transmit the noise into the passenger compartment and that replacing the generator may not solve the problem.

Generator Noise Diagnosis

Starter Solenoid Does Not Click

Starter Solenoid Does Not Click

Starter Solenoid Clicks, Engine Does Not Crank

Starter Solenoid Clicks, Engine Does Not Crank

Engine Cranks Slowly

Inspect the following items

1. Battery - Perform the Battery Inspection/Test. Refer to «Battery Inspection/Test»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Wiring - Inspect the wiring for damage. Inspect all connections to the starter motor, the solenoid, the battery and all ground connections. Refer to «Circuit Testing»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing) , «Wiring Repairs»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs) , «Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing) and «Connector Repairs»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs) in Wiring Systems.
3. Engine - Verify that the engine is not seized.

If the battery, the wiring and the engine are functioning properly and the engine continues to crank slowly, replace the starter motor. Refer to Starter Motor Replacement (L26) or Starter Motor Replacement (LY7) .

1. Inspect the flywheel ring gear for damage or unusual wear.
2. Shim the starter as required.
3. In order to add pinion to ring gear clearance a full size shim must be used. Do not shim only one starter mounting bolt. There are three shims available in different shapes, for clearance, all are 1 mm (0.039 in) thick.

Starter Motor Noise Diagnosis

Removal Procedure

1. Record all of the vehicle preset radio stations.
2. Turn OFF all the lamps and the accessories.
3. Ensure the ignition switch is in the OFF position.
4. Loosen the negative battery cable terminal nut.
5. Remove the negative battery terminal (2) from the battery.

Installation Procedure

1. Install the negative battery terminal (2) to the battery. Tighten: Tighten the negative battery terminal nut to 15 N.m (11 lb ft).
2. Set the clock and program the radio stations back into the radio as recorded at the beginning of the procedure for digital radios. Refer to «Digital Radio Receiver Setup»(/buick/lacrosse/i-2004-2009/remont/entertainment-systems/#entertainment-systems__digital-radio-receiver-setup) in Entertainment.

1. Turn off all the lamps and accessories.
2. Turn the ignition OFF.
3. Disconnect the battery negative cable (2) from the battery.

1. Connect the battery negative (2) cable to the battery. Tighten: Tighten the battery cable bolt to 17 N.m (13 lb ft).
2. Power Sunroof calibration: Turn the ignition switch to the RUN position. Turn the power sunroof switch to the closed position. After the sunroof fully closes and the motor stops, press and hold in the switch for 3 seconds. Turn the power sunroof switch to the tilt position. After the sunroof reaches the tilt position and the motor stops, press and hold in the switch for 3 seconds. Turn the power sunroof switch to the full open position. After the sunroof is fully open and the motor stops, press and hold in the switch for 3 seconds. Turn the power sunroof switch to the closed position. After the sunroof fully closes and the motor stops, press and hold in the switch for 3 seconds.
3. Power Windows calibration: Repeat these steps for each window. Turn the ignition switch to the RUN position. Press the power window switch to the down position. After the window is in the full down position, press and hold the switch in the down position for 3 seconds. Press the power window switch to the up position. After the window is in the full up position, press and hold the switch in the up position for 3 seconds.
4. Heat and A/C Control Head calibration: Turn the ignition switch to the RUN position. Simultaneously press the AUTO and OFF buttons, located on the heat and A/C control head, for at least 5 seconds. After initiation, the stepper motors will cycle from one stop to the other. You may hear the motors cycling while calibrating.

1. Disconnect the instrument panel (I/P) harness electrical connector (2) from the battery current sensor (1).
2. Remove the negative battery cable. Refer to «Battery Negative Cable Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Replacement (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Cut the tie straps and electrical tape attaching the battery current sensor to the battery cable.
4. Squeeze the negative battery cable branches together.
5. Slide the battery current sensor (1) off of the negative battery cable.

1. Slide the NEW battery current sensor (1) up onto the negative battery cable.
2. Using NEW tie straps and electrical tape, attach the battery current sensor to the negative battery cable.
3. Install the negative battery cable. Refer to «Battery Negative Cable Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Replacement (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Connect the I/P harness electrical connector (2) to the battery current sensor (1).

1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Loosen the positive battery terminal nut.
3. Remove the positive battery terminal (1) from the battery.
4. Remove the ground wire bolt (3) and the wire (4) from the frame.
5. Remove the positive battery cable junction block lead nut (1).
6. Remove the positive battery cable (2) from the bussed electrical center (BEC).
7. Remove the BEC (3) from the strut tower.
8. Unclip and remove the positive battery cable harness from the BEC.
9. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
10. Remove the front lower air deflector. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/buick/lacrosse/i-2004-2009/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.
11. Remove the positive battery cable nut (2) from the starter.
12. Remove the positive battery cable (3) from the starter motor BAT terminal.
13. Remove the transaxle stud nut (5).
14. Remove the engine ground cable (6) from the transaxle stud.
15. Unclip and remove the battery cable harness from the retainers.
16. Remove the battery cable harness from the vehicle.
17. Remove the negative battery cable from the wiring harness conduit.

1. Install the negative battery cable into the wiring harness conduit.
2. Install the battery cable harness to the vehicle.
3. Install the battery cable harness to the retainers.
4. Install the engine ground cable (6) to the transaxle stud.
5. Install the transaxle stud nut (5). Tighten: Tighten the nut to 30 N.m (22 lb ft).
6. Install the positive battery cable to the starter motor BAT terminal.
7. Install the starter solenoid BAT terminal nut. Tighten: Tighten the nut to 10 N.m (89 lb in).
8. Install the front lower air deflector. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/buick/lacrosse/i-2004-2009/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.
9. Lower the vehicle.
10. Install the positive battery cable harness to the BEC.
11. Install the BEC to the strut tower.
12. Install the positive battery cable (2) to the BEC (3).
13. Install the positive battery cable junction block lead nut (1). Tighten: Tighten the nut to 10 N.m (89 lb in).
14. Install the ground wire (4) and the bolt (3) to the frame. Tighten: Tighten the bolt to 10 N.m (89 lb in).
15. Install the positive battery terminal (1) to the battery. Tighten: Tighten the nut to 15 N.m (11 lb ft).
16. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the bolt (1) securing the battery negative cable to the side rail.
3. Disconnect the body harness connector (3) from the battery negative cable.
4. Remove the bolt securing the battery negative cable to the engine block.
5. Lower the vehicle.
6. Remove the battery negative cable from the engine.

1. Position the battery negative cable to the engine.
2. Install the battery negative cable to engine bolt. Tighten: Tighten the battery negative cable to engine bolt to 50 N.m (37 lb ft).
3. Install the bolt (1) securing the battery negative cable to the side rail. Tighten: Tighten the battery negative cable to side rail bolt to 36 N.m (27 lb ft).
4. Connect the body harness connector (3) to the battery negative cable.
5. Connect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Loosen the positive battery terminal nut.
3. Remove the positive battery terminal (1) from the battery.
4. Remove the ground wire bolt (3) and the wire (4) from the frame.
5. Remove the positive battery cable junction block lead nut (1).
6. Remove the positive battery cable (2) from the bussed electrical center (BEC).
7. Remove the BEC (3) from the strut tower.
8. Unclip and remove the positive battery cable harness from the BEC.
9. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
10. Remove the front lower air deflector. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/buick/lacrosse/i-2004-2009/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.
11. Remove the positive battery cable nut (2) from the starter.
12. Remove the positive battery cable (3) from the starter motor BAT terminal.
13. Remove the transaxle stud nut (5).
14. Remove the engine ground cable (6) from the transaxle stud.
15. Unclip and remove the battery cable harness from the retainers.
16. Remove the battery cable harness from the vehicle.
17. Remove the positive battery cable from the wiring harness conduit.

1. Install the positive battery cable into the wiring harness conduit.
2. Install the battery cable harness to the vehicle.
3. Install the battery cable harness to the retainers.
4. Install the engine ground cable (6) to the transaxle stud.
5. Install the transaxle stud nut (5). Tighten: Tighten the nut to 30 N.m (22 lb ft).
6. Install the positive battery cable to the starter motor BAT terminal.
7. Install the starter solenoid BAT terminal nut. Tighten: Tighten the nut to 10 N.m (89 lb in).
8. Install the front lower air deflector. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/buick/lacrosse/i-2004-2009/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.
9. Lower the vehicle.
10. Install the positive battery cable harness to the BEC.
11. Install the BEC to the strut tower.
12. Install the positive battery cable (2) to the BEC (3).
13. Install the positive battery cable junction block lead nut (1). Tighten: Tighten the nut to 10 N.m (89 lb in).
14. Install the ground wire (4) and the bolt (3) to the frame. Tighten: Tighten the bolt to 10 N.m (89 lb in).
15. Install the positive battery terminal (1) to the battery. Tighten: Tighten the nut to 15 N.m (11 lb ft).
16. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Disconnect the battery positive cable from the battery.
3. Depress the tabs in order to remove the cover from the electrical center.
4. Remove the nut (1) securing the battery positive cable (2) to the electrical center.
5. Reposition the protective boot from the generator output BAT terminal for access.
6. Remove the generator output BAT terminal nut (3) and disconnect the battery positive lead (2) from the generator.
7. Remove the starter terminal nut (1) and disconnect the battery positive cable (2) from the starter.
8. Lower the vehicle.
9. Remove the battery positive cable from the engine.

1. Position the battery positive cable to the engine.
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
3. Connect the battery positive cable (2) to the starter and install the starter terminal nut (1). Tighten: Tighten the battery positive cable nut to 13 N.m (115 lb in).
4. Connect the battery positive lead (2) to the generator and install the generator BAT terminal nut (3). Tighten: Tighten the generator BAT terminal nut to 13 N.m (115 lb in).
5. Install the protective boot to the generator output BAT terminal.
6. Lower the vehicle.
7. Install the nut (1) securing the battery positive cable (2) to the electrical center. Tighten: Tighten the battery positive cable to electrical center nut to 15 N.m (11 lb ft).
8. Install the electrical center cover.
9. Connect the battery positive cable to the battery. Tighten: Tighten the battery cable to 17 N.m (13 lb ft).
10. Connect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the right front diagonal brace. Refer to «Brace Replacement - Front Fender Upper Diagonal»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
3. Loosen the positive battery terminal nut.
4. Remove the positive battery terminal (1) from the battery.
5. Remove the battery hold down.
6. Remove the battery.
7. Remove the insulator from the battery.

1. Install the insulator to the battery.
2. Install the battery.
3. Install the battery hold down.
4. Install the battery hold down bolt. Tighten: Tighten the bolt to 18 N.m (13 lb ft).
5. Install the positive battery terminal (1) to the battery. Tighten: Tighten the nut to 15 N.m (11 lb ft).
6. Install the right front diagonal brace. Refer to «Brace Replacement - Front Fender Upper Diagonal»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
7. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Disconnect the battery positive cable from the battery.
3. Remove the battery retainer bolt and battery retainer.
4. Remove the battery from the vehicle.
5. Remove the battery heat shield. Refer to CELL LINK .

1. Install the battery heat shield. Refer to CELL LINK .
2. Install the battery into the vehicle.
3. Install the battery retainer and bolt. Tighten: Tighten the battery retainer bolt to 25 N.m (18 lb ft).
4. Connect the battery positive cable to the battery. Tighten: Tighten the battery cable bolt to 17 N.m (13 lb ft).
5. Connect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the battery. Refer to «Battery Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Replacement (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Remove the battery tray bolts.
4. Remove the battery tray.

1. Install the battery tray.
2. Install the battery tray bolts. Tighten: Tighten the battery tray bolts to 5 N.m (44 lb in).
3. Install the battery. Refer to «Battery Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Replacement (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Remove the battery. Refer to «Battery Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Replacement (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the right air inlet grill panel only. Refer to «Air Inlet Grille Panel Replacement»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
3. Remove the 2 bolts securing the front air inlet panel assembly to the battery tray.
4. Remove the battery tray bolts from the following: The inner fender panel The shock tower The lower air inlet panel assembly
5. Remove the battery tray (2) from the vehicle.

1. Position the battery tray (2) to the vehicle, locating the alignment datums (1) with the holes in the inner fender.
2. Install the battery tray bolts to the following: The inner fender panel The shock tower The lower air inlet panel assembly Tighten: Tighten the battery tray bolts to 6 N.m (53 lb in).
3. Install the 2 bolts securing the front air inlet panel assembly to the battery tray. Tighten: Tighten the front air inlet panel assembly bolts to 6 N.m (53 lb in).
4. Install the right air inlet grill panel. Refer to «Air Inlet Grille Panel Replacement»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
5. Install the battery. Refer to «Battery Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Replacement (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Remove the battery. Refer to «Battery Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Replacement (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Lift the battery heat shield upward from the battery.

1. Position the battery heat shield downward over the battery.
2. Install the battery. Refer to «Battery Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Replacement (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
3. Remove the front lower air deflector panel. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/buick/lacrosse/i-2004-2009/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.
4. Remove the torque converter covers. Refer to «Torque Converter Cover Replacement»(/buick/lacrosse/i-2004-2009/remont/automatic-trans/#automatic-transaxle-4t65-e-introduction-2-of-2) in Automatic Transaxle - 4T65-E.
5. Remove the starter solenoid S terminal nut (9) and remove the starter solenoid wire (8) from the starter motor.
6. Remove the starter solenoid BAT terminal nut (2) and remove the positive battery cable (3) from the starter motor.
7. Remove the starter bolts (1, 2) and the starter motor.

1. Align the starter motor to the engine.
2. Install the starter bolts (1, 2) finger tight until seated. Tighten: Tighten the starter bolts to 43 N.m (32 lb ft).
3. Install the positive battery cable (3) and the solenoid BAT terminal nut (2). Tighten finger tight to the starter motor.
4. Install the starter solenoid wire (8) and the starter solenoid S terminal nut (9). Tighten finger tight to the starter motor. Tighten: Tighten the solenoid BAT terminal nut (2) to 9.5 N.m (84 lb in). Tighten the starter solenoid S terminal nut (9) to 2.3 N.m (20 lb in).
5. Install the torque converter covers. Refer to «Torque Converter Cover Replacement»(/buick/lacrosse/i-2004-2009/remont/automatic-trans/#automatic-transaxle-4t65-e-introduction-2-of-2) in Automatic Transaxle - 4T65-E.
6. Install the front lower air deflector panel. Refer to «Radiator Air Baffle and Deflector Replacement - Lower»(/buick/lacrosse/i-2004-2009/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.
7. Lower the vehicle.
8. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Turn the ignition OFF.
2. Disconnect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Remove the starter solenoid electrical connector from the starter.
4. Remove the starter terminal nut (1) and the battery positive cable (2) from the starter.
5. Remove the starter motor bolts.
6. Remove the starter motor.

1. Install the starter motor.
2. Install the starter motor mounting bolts Tighten: Tighten the starter motor mounting bolts to 50 N.m (37 lb ft).
3. Install the battery positive cable (2) to the starter and install the starter terminal nut (1). Tighten: Tighten the battery positive cable nut to 13 N.m (115 lb in).
4. Install the electrical connector to the starter solenoid.

1. Disconnect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the right catalytic converter. Refer to CELL LINK in Engine Exhaust.
3. Remove the fasteners securing the starter heat shield to the starter.
4. Remove the starter heat shield.
5. Remove the nut securing the starter heat shield mounting bracket to the starter.
6. Remove the starter heat shield mounting bracket.
7. Remove the nut securing the starter heat shield mounting bracket to the engine block.
8. Remove the starter heat shield mounting bracket.

1. Install the starter heat shield mounting bracket to the stud located at the engine block.
2. Install the nut securing the starter heat shield mounting bracket to the engine block. Tighten: Tighten the starter heat shield mounting bracket nut to 8 N.m (71 lb in).
3. Install the starter heat shield mounting bracket to the stud located at the rear of the starter motor.
4. Install the nut securing the starter heat shield mounting bracket to the starter. Tighten: Tighten the starter heat shield mounting bracket nut to 8 N.m (71 lb in).
5. Position the starter heat shield to the starter motor and brackets.
6. Install the fasteners securing the starter heat shield to the starter motor and brackets. Tighten: Tighten the starter heat shield fasteners to 8 N.m (71 lb in).
7. Install the right catalytic converter. Refer to CELL LINK in Engine Exhaust.
8. Connect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Turn the ignition OFF.
2. Remove the generator. Refer to «Generator Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Remove the coolant inlet pipe lower bolt from the generator bracket.
4. Remove the belt tensioner. Refer to «Drive Belt Tensioner Replacement»(/buick/lacrosse/i-2004-2009/remont/mechanical/#engine-mechanical-36l-ly7-repair-instructions-1-of-5) .
5. Remove the generator bracket bolts.
6. Remove the generator bracket.

1. Install the generator bracket.
2. Install the generator bracket bolts. Tighten: Tighten the generator bracket bolts in the sequence shown. Tighten the generator bracket bolts (1) to 50 N.m (37 lb in). Tighten the generator bracket bolts (2) to 50 N.m (37 lb in). Tighten the generator bracket bolt (3) to 23 N.m (17 lb in).
3. Install the belt tensioner. Refer to «Drive Belt Tensioner Replacement»(/buick/lacrosse/i-2004-2009/remont/mechanical/#engine-mechanical-36l-ly7-repair-instructions-1-of-5) .
4. Install the coolant inlet pipe lower bolt from the generator bracket.
5. Install the generator. Refer to «Generator Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Remove the generator rear brace nut (5).
2. Remove the generator rear brace bolt (3).
3. Remove the generator rear brace (4).

1. Install the generator rear brace (4).
2. Install the generator rear brace bolt (3).
3. Install the generator rear brace nut (5).
4. Tighten the generator bolts in the order described. The following is a mandatory torque sequence: Tighten: Tighten the generator rear brace bolt (3) to 50 N.m (37 lb ft). Tighten the generator rear brace nut (5) to 50 N.m (37 lb ft).

1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the drive belt from the generator. Refer to «Drive Belt Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/mechanical/#engine-mechanical-38l) in Engine Mechanical - 3.8L.
3. Remove the generator rear brace. Refer to «Generator Brace Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Remove the bolts (1, 3) and the stud (2) from the generator.
5. Disconnect the electrical connector from the generator.
6. Position aside the protective boot from the generator output BAT terminal for access.
7. Remove the generator output BAT terminal nut and remove the positive battery lead from the generator.
8. Remove the generator.

1. Position the generator to the engine.
2. Install the positive battery lead to the generator.
3. Install the generator output BAT terminal nut. Tighten: Tighten the generator output BAT terminal nut to 20 N.m (15 lb ft).
4. Install the protective boot to the generator output BAT terminal.
5. Connect the electrical connector to the generator.
6. Install the generator stud (2) to the generator bracket.
7. Install the generator bolts (1, 3) to the generator bracket.
8. Tighten the generator bolts and stud in the order described. The following is a mandatory torque sequence: Tighten: Tighten the generator bolt (1) to 50 N.m (37 lb ft). Tighten the generator stud (2) to 50 N.m (37 lb ft). Tighten the generator rear bracket bolt (3) to 50 N.m (37 lb ft).
9. Install the generator rear brace. Refer to «Generator Brace Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
10. Install the drive belt. Refer to «Drive Belt Replacement (L26)»(/buick/lacrosse/i-2004-2009/remont/mechanical/#engine-mechanical-38l) in Engine Mechanical - 3.8L.
11. Connect the negative battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the drive belt from the generator. Refer to «Drive Belt Tensioner Replacement»(/buick/lacrosse/i-2004-2009/remont/mechanical/#engine-mechanical-36l-ly7-repair-instructions-1-of-5) in Engine Mechanical - 3.6L (LY7).
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
4. Disconnect the electrical connector (1) from the generator.
5. Reposition the protective boot from the generator output BAT terminal for access.
6. Remove the generator output BAT terminal nut (3) and disconnect the battery positive lead (2) from the generator.
7. Remove the generator lower bolts.
8. Lower the vehicle.
9. Remove the generator upper bolt.
10. Remove the generator from the engine.

1. Install the generator to the engine.
2. Install the generator upper bolt.
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/i-2004-2009/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
4. Install the generator lower bolts. Tighten: Tighten the generator bolts to 50 N.m (37 lb ft).
5. Install the battery positive lead (2) and the generator BAT terminal nut (3) to the generator. Tighten: Tighten the generator BAT terminal nut to 10 N.m (89 lb in).
6. Install the BAT terminal boot.
7. Connect the electrical connector (1) to the generator.
8. Lower the vehicle.
9. Install the drive belt to the generator. Refer to «Drive Belt Tensioner Replacement»(/buick/lacrosse/i-2004-2009/remont/mechanical/#engine-mechanical-36l-ly7-repair-instructions-1-of-5) in Engine Mechanical - 3.6L (LY7).
10. Connect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure (L26)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnect/Connect Procedure (LY7)»(/buick/lacrosse/i-2004-2009/remont/charging-system/#battery-charging-system-and-starting-system) .

Battery Description and Operation (LY7)

Batteries that are no longer wanted must be disposed of by an approved battery recycler and must never be thrown in the trash or sent to a landfill.

Batteries that are not part of the vehicle itself, not the battery under the hood, must only be transported on public streets for business purposes via approved hazardous material transportation procedures.

Battery storage, charging and testing facilities in repair shops must meet various requirements for ventilation, safety equipment, material segregation, etc.

Scheme 6

The maintenance free Absorbent Glass Mat (AGM) battery is the standard original equipment battery. The battery is completely sealed except for one vent port in the end of the cover. The vent port allows the small amount of gas that is produced in the battery to escape when pressures exceed 2 psi. The AGM battery is a lead-acid battery that is similar to current batteries. They use glass mats that absorb electrolyte that are pressed between the plates instead of immersing the plates in electrolyte. This allows a smaller, lighter battery with the same amount of power which is less susceptible to heat.

The battery has three functions as a major source of energy

1. Engine cranking
2. Voltage stabilizer
3. Alternate source of energy with generator overload and during key off.

The battery specification label (see typical figure) contains information about the following

1. The test ratings
2. The original equipment catalog number
3. The recommended replacement model number

Scheme 7

Battery Ratings

A battery has two ratings

1. Reserve capacity (RC)
2. Cold cranking amperage (CCA)

When a battery is replaced use a battery with similar ratings. Refer to the battery specification label on the original battery or refer to Battery Usage .

Reserve Capacity (RC)

The RC is an indication of the battery's ability to produce a relatively low amount of current over a long period of time and is also an indication of the battery's energy storage capability. The RC rating is the amount of time in minutes it takes a fully charged battery at 27°C (80°F) to reach a terminal voltage of 10.5 volts when it is being discharged at a constant rate of 25 amperes. Refer to Battery Usage for the reserve capacity rating of the original equipment battery.

Cold Cranking Amperage (CCA)

The cold cranking amperage is an indication of the ability of the battery to provide high power to crank the engine at cold temperatures. The cold cranking amperage rating is the minimum amperage the battery must maintain for 30 seconds at -18°C (0°F) while maintaining at least 7.2 volts across its terminals. Refer to Battery Usage for the cold cranking amperage rating for this vehicle.

The battery positive terminal supplies battery positive voltage to the under hood fuse block and the rear fuse block. The under hood fuse block provides a cable connection for the generator and a cable connection for the starter.

Battery Description and Operation (L26)

Batteries that are no longer wanted must be disposed of by an approved battery recycler and must never be thrown in the trash or sent to a landfill.

Batteries that are not part of the vehicle itself, not the battery under the hood, must only be transported on public streets for business purposes via approved hazardous material transportation procedures.

Battery storage, charging and testing facilities in repair shops must meet various requirements for ventilation, safety equipment, material segregation, etc.

The maintenance-free battery is standard. There are no vent plugs in the cover. The battery is completely sealed except for 2 small vent holes in the side. These vent holes allow the small amount of gas that is produced in the battery to escape.

The battery has 3 functions as a major source of energy

1. Engine cranking
2. Voltage stabilizer
3. Alternate source of energy with generator overload

The battery specification label, example below, contains information about the following

1. The test ratings
2. The original equipment catalog number
3. The recommended replacement model number

Scheme 8

A battery may have 3 ratings

1. Amp hour (AH)
2. Reserve capacity (RC)
3. Cold cranking amperage (CCA)

When a battery is replaced, use a battery with similar ratings. Refer to the battery specification label on the original battery or refer to Battery Usage .

Amp Hour (AH)

The amp hour rating of a battery is the amount of time it takes a fully charged battery, being discharged at a constant rate of 1 amperes and a constant temperature of 27°C (80°F), to reach a terminal voltage of 10.5 volts. Refer to Battery Usage for the amp hour rating of the original equipment battery.

Reserve capacity is the amount of time in minutes it takes a fully charged battery, being discharged at a constant rate of 25 amperes and a constant temperature of 27°C (80°F), to reach a terminal voltage of 10.5 volts. Refer to Battery Usage for the reserve capacity rating of the original equipment battery.

The cold cranking amperage is an indication of the ability of the battery to crank the engine at cold temperatures. The cold cranking amperage rating is the minimum amperage the battery must maintain for 30 seconds at -18°C (0°F) while maintaining at least 7.2 volts. Refer to Battery Usage for the cold cranking amperage rating for this vehicle.

Electrical Power Management (EPM) Overview

The electrical power management (EPM) system is designed to monitor and control the charging system and send diagnostic messages to alert the driver of possible problems with the battery and generator. This EPM system primarily utilizes existing on-board computer capability to maximize the effectiveness of the generator, to manage the load, improve battery state-of-charge (SOC) and life and minimize the system's impact on fuel economy. The EPM system performs 3 basic functions

1. It monitors the battery voltage and estimates the battery condition.
2. It takes corrective actions by adjusting the regulated voltage.
3. It performs diagnostics and driver notification.

The battery's condition is estimated during key-off and during key-on. During key-off the SOC of the battery is determined by measuring the open-circuit voltage. The SOC is a percentage number, with 100 percent being fully charged and 0 percent being fully discharged. A normal SOC value is typically greater than 80 percent.

The SOC can be used as a diagnostic tool to tell the customer or the dealer the condition of the battery. Throughout key-on operation, the EPM software (algorithm) continuously estimates SOC based on adjusted net amp hours, battery capacity, initial SOC and temperature.

While running, the battery's degree of discharge is primarily determined by a battery current sensor, which is integrated to obtain net amp hours.

In addition, the EPM function is designed to perform regulated voltage control (RVC) to improve battery SOC, battery life and fuel economy. This is accomplished by using knowledge of the battery's SOC and temperature to set the charging voltage to an optimum battery voltage level for recharging without detriment to battery life.

The Charging System Description and Operation is divided into 3 sections. The first section describes the charging system components and their integration into the EPM. The second section describes charging system operation. The third section describes the instrument panel cluster operation of the charge indicator, driver information center messages and voltmeter operation.

Generator

The generator is a serviceable component. If there is a diagnosed failure of the generator it must be replaced as an assembly. The engine drive belt drives the generator. When the rotor is spun it induces an alternating current (AC) into the stator windings. The AC voltage is then sent through a series of diodes for rectification. The rectified voltage has been converted into a direct current (DC) for use by the vehicles electrical system to maintain electrical loads and the battery charge. The voltage regulator integral to the generator controls the output of the generator. It is not serviceable. The voltage regulator controls the generator's output voltage by controlling the amount of current provided to the rotor. The generator on this vehicle has RVC, which means that the EPM software determines what the regulated voltage should be, not the generator. The output voltage command comes to the generator from the engine control module (ECM)/powertrain control module (PCM) by way of the "L" terminal. If that signal is lost, the generator defaults to an output voltage of 13.8 volts.

Body Control Module (BCM)

The body control module (BCM) is a class 2 device utilizing digital serial data links with other control modules. The BCM contains the EPM software and communicates with the ECM/PCM and the instrument panel cluster for EPM operation. The BCM determines the desired output voltage of the generator and sends the voltage command to the ECM/PCM for transmittal via the "L" terminal line to the regulator. The BCM also monitors the generator field duty cycle signal (F terminal) sent via the ECM/PCM. The BCM monitors the battery current sensor, the battery positive voltage and estimated battery temperature to determine SOC. The BCM commands idle boost and load management operations, whenever battery discharge warrants it.

Battery Current Sensor

The battery current sensor is a serviceable component that is assembled on the negative battery cable at the battery. The battery current sensor is a 3 wire hall effect current sensor. The battery current sensor monitors the battery current. It directly inputs to the BCM. It creates a 5-volt pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes.

Engine Control Module (ECM)/Powertrain Control Module (PCM)

The ECM/PCM directly controls the generator field control circuit input to the generator. It monitors the generators generator field duty cycle signal circuit and sends the information to the BCM.

Instrument Panel Cluster (IPC)

The IPC provides a means of customer notification in case of a failure and a voltmeter. There are 2 means of notification, a charge indicator and a driver information center message of SERVICE CHARGING SYSTEM and CHARGING SYSTEM FAULT.

Charging System Operation

The purpose of the charging system is to maintain the battery charge and vehicle loads. There are 5 modes of operation and they include

1. Charge Mode
2. Fuel Economy Mode
3. Voltage Reduction Mode
4. Start Up Mode
5. Battery Sulfation Mode

The ECM/PCM controls the generator through the generator field control circuit. It monitors the generator performance through the generator field duty cycle signal circuit. The signal is a 5-volt pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes. The following table shows the commanded duty cycle and output voltage of the generator

Charging System Description and Operation

The generator provides a feedback signal of the generator voltage output through the generator field duty cycle signal circuit to the ECM/PCM, this information is sent to the BCM. The signal is a 5-volt PWM signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-99 percent. Between 0-5 percent and 100 percent are for diagnostic purposes.

Charge Mode

The BCM will enter Charge Mode when ever one of the following conditions are met

1. The headlamps are ON, low or high beam.
2. The wipers are ON for more than 3 seconds.
3. The electric cooling fans are on high speed for more than 1 minute and either fluid head pressure is greater than 1600 kpa (232 PSI) or engine coolant temperature is greater than 105°C (221°F).
4. The rear defogger is ON for more than 1 minute.
5. The HVAC front blowers are on high speed for more than 1 minute and estimated battery temperature is greater than 32°C (89°F).
6. The estimated battery temperature is less than 0°C (32°F).
7. Battery SOC is less than 80 percent.

Once one of these conditions is met, the generator battery control module will set the targeted generator output voltage to a charging voltage between 13.9 volts and 15.5 volts, depending on battery SOC and estimated battery temperature.

Fuel Economy Mode

The BCM will enter Fuel Economy Mode when the estimated battery temperature is above 0°C (32°F), the calculated battery current is less than 15 amperes and greater than -8 amperes and the battery SOC is greater than 80 percent. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.56 volts and 13.2 volts. The BCM will exit this mode once the criteria are met for Charge Mode.

Voltage Reduction Mode

The BCM will enter Voltage Reduction Mode when the estimated battery temperature is above 0°C (32°F), the calculated battery current is less than 1 amperes and greater than -7 amperes and the generator field duty cycle is less than 99 percent. Its targeted generator output voltage is 12.9 volts. The BCM will exit this mode once the criteria are met for Charge Mode. If the conditions for both Fuel Economy Mode and Voltage Reduction Mode are met at the same time, Fuel Economy Mode has priority.

Start Up Mode

After the engine has started the BCM sets a targeted generator output voltage of 14.5 volts for 30 seconds.

Battery Sulfation Mode

The BCM will enter this mode when the interpreted generator output voltage is less than 13.2 volts for 45 minutes. Once in this mode the BCM will enter Charge Mode. The BCM will then determine which mode to enter depending on voltage requirements.

Charge Indicator Operation

The instrument panel cluster (IPC) illuminates the charge indicator in the message center when the one or more of the following occurs

1. The ECM/PCM detects that the generator output is less than 11 volts or greater than 16 volts. The IPC receives a class 2 message from the ECM/PCM requesting illumination.
2. The IPC determines that the system voltage is less than 11.3 volts or greater than 16.2 volts for more than 30 seconds. The IPC receives a class 2 message from the body control module (BCM) indicating there is a system voltage range concern.
3. The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
4. The ignition is ON, with the engine OFF.

Charging System Failure

The ECM/PCM will send a class 2 message to the IPC for the CHARGING SYSTEM FAILURE message to be displayed. It is commanded ON when a charging system DTC is a current DTC. The message is turned off when the conditions for clearing the DTC have been met.

Battery Voltage

The IPC displays the system voltage as received from the BCM over the class 2 serial data circuit. If there is no communication with the BCM, then the display will read all dashes until communication is restored.

Battery Saver Active

The BATTERY SAVER ACTIVE message will display on the DIC when the vehicle enters a load shed 2 event. Refer to Load Shed System Description and Operation for load shed 2 criteria.

Starting System Description and Operation

The PG starter motors are non-repairable starter motors. They have pole pieces that are arranged around the armature. Both solenoid windings are energized. The pull-in winding circuit is completed to the ground through the starter motor. The windings work together magnetically to pull and hold in the plunger. The plunger moves the shift lever. This action causes the starter drive assembly to rotate on the armature shaft spline as it engages with the flywheel ring gear on the engine. Moving at the same time, the plunger also closes the solenoid switch contacts in the starter solenoid. Full battery voltage is applied directly to the starter motor and it cranks the engine.

As soon as the solenoid switch contacts close, current stops flowing thorough the pull-in winding because battery voltage is applied to both ends of the windings. The hold-in winding remains energized; its magnetic field is strong enough to hold the plunger, shift lever, starter drive assembly and solenoid switch contacts in place to continue cranking the engine. When the engine starts, pinion overrun protects the armature from excessive speed until the switch is opened.

When the ignition switch is released from the START position, the CRANK Relay opens and battery voltage is removed from the starter solenoid S terminal. Current flows from the motor contacts through both windings to the ground at the end of the hold-in winding. However, the direction of the current flow through the pull-in winding is now opposite the direction of the current flow when the winding was first energized.

The magnetic fields of the pull-in and hold-in windings now oppose one another. This action of the windings, along with the help of the return spring, causes the starter drive assembly to disengage and the solenoid switch contacts to open simultaneously. As soon as the contacts open, the starter circuit is turned off.

When the ignition switch is placed in the Start position a discrete 12 volts signal is supplied to the body control module (BCM) notifying it that the ignition is in the Start position. The BCM then supplies a class 2 message to the engine control module (ECM)/powertrain control module (PCM) notifying it that CRANK has been requested. At the same time the BCM is supplying 12 volts for the IGN 1 Relay closing it and supplying battery positive voltage for the crank relay coil. The ECM/PCM verifies that the transmission is in Park or Neutral. If it is, the ECM/PCM grounds the control circuit of the CRANK Relay. When this occurs battery positive voltage is supplied through the switch side of the crank relay to the S terminal of the starter solenoid. For remote vehicle start (RVS) information, refer to Keyless Entry System Description and Operation .

Electrical Power Management

The electrical power management (EPM) is used to monitor and control the charging system and alert the driver of possible problems within the charging system. The EPM system makes the most efficient use of the generator output, improves the battery state of charge (SOC), extends battery life and manages system electrical loads.

The load shed operation is a means of reducing electrical loads during a low voltage or low battery SOC condition.

The idle boost operation is a means of improving generator performance during a low voltage or low battery SOC condition.

Each EPM function, either idle boost or load-shed, is discrete. No 2 functions are active at the same time. Idle boost is activated in incremental steps, idle boost 1 must be active before idle boost 2 can be active. The criteria used by the body control module (BCM) to regulate EPM are outlined below

Load Shed System Description and Operation

Special Tools

Special Tools Illustration Tool Number/Description J 38758 Parasitic Draw Test Switch J 42000 Battery Tester

Scheme 9

Scheme 10

See also:
• Diagnostic System Check - Vehicle
• Inline Harness Connector End Views
• Computer/Integrating Systems Connector End Views
• Circuit Testing
• Wiring Repairs
• Testing for Intermittent Conditions and Poor Connections
• Connector Repairs
• Control Module References
• Engine Controls Schematics
• Engine Controls Connector End Views
• Power and Grounding Connector End Views
• Engine Controls Schematics
• Engine Control Module (ECM) Connector End Views
• Powertrain Control Module (PCM) Connector End Views
• Checking Aftermarket Accessories
• BATTERY DISCONNECT CAUTION
• FASTENER NOTICE
• Body Control System Description and Operation
• Keyless Entry System Description and Operation
• Drive Belt Replacement (L26)
• Drive Belt Replacement
• Drive Belt Tensioner Diagnosis
• Drive Belt Tensioner Diagnosis
• Master Electrical Component List
• Range Selector Displays Incorrect Range (3.6L)
• Engine Will Not Crank - Crankshaft Will Not Rotate
• Engine Will Not Crank - Crankshaft Will Not Rotate
• Engine Flywheel Removal
• Engine Flywheel Replacement
• SIR Caution
• Digital Radio Receiver Setup
• Lifting and Jacking the Vehicle
• Radiator Air Baffle and Deflector Replacement - Lower
• Brace Replacement - Front Fender Upper Diagonal
• Torque Converter Cover Replacement
• DTC B1327
• Charging System Test
• Engine Electrical Connector End Views
• Battery Description and Operation (LY7)
• Battery Description and Operation (L26)
• Starting System Description and Operation
• Battery Common Causes of Failure
• Charge Indicator Always On
• Charge Indicator Inoperative
• Starter Solenoid Does Not Click
• Starter Solenoid Clicks, Engine Does Not Crank
• Engine Cranks Slowly
• Special Tools
• Battery Usage
• Generator Usage