Battery, Charging System and Starting System Chevrolet Cobalt 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

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Engine Electrical Connector End Views

Battery Current Sensor Connector Part Information OEM: 15326808 Service: See Catalog 3-Way F GT 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A GY 596 5-Volt Reference B TN/WH 1704 Sensor Low Reference C WH 5075 Current Sensor Signal

Clutch Pedal Position (CPP) Switch (M86) Connector Part Information OEM: 15479480 Service: See Catalog 2-Way F Micro-Pack 280 Series (L-GY) Pin Wire Color Circuit No. Function A BN/WH 379 CPP Switch Signal B PK/BK 5291 Ignition 1 Voltage

Clutch Start Switch (M86) Connector Part Information OEM: 12041433 Service: See Catalog 2-Way F Metri-Pack 280 Series (BK) Pin Wire Color Circuit No. Function A PK 339 Ignition 1 Voltage B YE 575 Starter Control

Generator (L61) Connector Part Information OEM: 12186308 Service: See Catalog 2-Way F Timer JR-Power Sealed (BK) Pin Wire Color Circuit No. Function 1 OG 225 Generator Turn On Signal 2 GY/WH 23 Generator Field Duty Cycle Signal

Generator (LSJ) Connector Part Information OEM: 15355066 Service: See Catalog 2-Way F Metri-Pack 150 Series Sealed (BG) Pin Wire Color Circuit No. Function A - - Not Available B RD 225 Generator Turn On Signal C GY 23 Generator Field Duty Cycle Signal D - - Not Available

Fuse Holder - 50 AMP Connector Part Information OEM: 12110057 Service: See Catalog 2-Way F Maxi (BK) Pin Wire Color Circuit No. Function A RD/BK 142 Battery Positive Voltage B RD 1 Unfused Battery Positive Voltage

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

LSJ Powertrain Control Module (PCM)

L61 Engine Control Module (ECM)

Scan Tool Data List

Body Control Module (BCM)

LSJ Powertrain Control Module (PCM)

L61 Engine Control Module (ECM)

Transmission Control Module (TCM)

Circuit Description

The control modules on this vehicle monitor the battery voltage through the battery positive voltage circuits.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC B1325 Device Power 1 Circuit

This vehicle has DTCs that include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC B1325

Conditions for Running the DTC

The voltage supplied to the control modules is in the range of 7-26 volts.

B1325 03

The control module detects a system voltage below 9 volts and the condition is present at least 5 seconds.

B1325 07

The control module detects a system voltage above 18 volts and the condition is present at least 5 seconds.

Action Taken When the DTC Sets

1. The control module immediately disables all outputs when a high voltage condition is detected, with the exception of GMLAN and Run/Crank relay that are disabled after a 3 minute delay.
2. The setting of other DTCs is inhibited.

Conditions for Clearing the DTC

1. A current DTC clears when the malfunction is no longer present.
2. A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

DTC B1325

The engine control module (ECM)/powertrain control module (PCM) controls the generator through the generator L-terminal control 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. If the generator L-terminal control circuit is in the 0-5 percent range, pulled low to ground or open then DTC B1485 will set.

This diagnostic procedure supports the following DTC

DTC B1485 Generator L-Terminal Circuit

This vehicle has DTCs that include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC B1485

1. The engine speed is greater than 450 RPM.
2. This diagnostic shall be run every 100 milliseconds.

B1485 04

Sets as current when the generator L-terminal control circuit is less than or equal to 5 percent duty cycle for more than 120 seconds.

The ECM/PCM will request the driver information center (DIC) message of Charging System Fault and commands on the Battery indicator.

1. The generator L-terminal control circuit input is greater than 5 percent duty cycle.
2. Clear the DTC with a scan tool.

Diagnostic Aids

Recommended Action

1. Correct L-terminal short low condition.
2. Clear the codes.
3. Cycle the ignition.

If a fault condition persists, replace the module.

DTC B1485

The engine control module (ECM)/powertrain control module (PCM) monitors the generator through the generator field duty cycle signal circuit. The signal is a 12-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. If the generator field duty cycle signal circuit is in the 0-5 percent range or pulled low to ground then DTC B1490 will set.

This diagnostic procedure supports the following DTC

DTC B1490 Generator F-Terminal Circuit

This vehicle has DTCs that include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC B1490

1. The engine speed is less that 1,000 RPM.
2. DTC B1487 or B1488 is not set as a current DTC.

B1490 01

Sets as current when the duty cycle of the generator field duty cycle signal circuit is less than or equal to 5 percent duty cycle for more than 120 seconds.

The ECM/PCM will request the driver information center (DIC) message of Charging System Fault and commands on the Battery indicator.

1. The generator field duty cycle signal circuit input is greater than 5 percent duty cycle.
2. Clear the DTC with a scan tool.

Recommended Action

1. Correct F-terminal short low condition.
2. Clear the codes.
3. Cycle the ignition.

If a fault condition persists, replace the module.

DTC B1490

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 instrument panel cluster (IPC) 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

This vehicle has DTCs that include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC B1516

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

B1516 08

Sets as current when the duty cycle of the PWM input signal is less than 4 percent or more than 96 percent for more than 15 seconds.

The CHARGING SYSTEM FAILURE warning message will be set in the driver information center (DIC).

Conditions for Clearing the MIL/DTC

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

DTC B1516

The body control module (BCM) has designated circuits for monitoring vehicle system voltage. Other modules also monitor system voltage. The BCM has 3 power inputs circuits and 2 main ground circuits. When the BCM sets B1517, the system voltage message is sent to the other modules and will default to 12.9 volts.

This diagnostic procedure supports the following DTC

DTC B1517 Battery Voltage (signal or 1) Voltage

This vehicle has DTCs that include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC B1517

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, except when the DTC B1391 is set current.

B1517 03

The battery voltage falls below 11 volts.

B1517 07

The battery voltage is greater than 16 volts.

B1517 52

A comparison failure occurred.

The driver information center (DIC) displays the Battery Voltage Low Message.

The DIC displays the Battery Voltage High Message.

The DIC displays the SERVICE VEHICLE SOON Message.

1. The DTC will clear current status when the fault is no longer present.
2. A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
3. Use the On-Board clearing DTCs feature.
4. Use a scan tool.

Test Description

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

1. 3: This step tests for the proper voltage at battery positive voltage sense circuits of the BCM. If voltages are not within the proper operating range, the voltage sense circuits needs to be tested.
2. 4: This step tests the ground sense circuits of the BCM.
3. 5: This step tests for the proper voltage of the circuits to the BCM. If voltage is not within the proper operating range, the battery positive voltage and ground circuits of the BCM need to be tested.

DTC B1517

The engine control module (ECM)/powertrain control module (PCM) 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/PCM monitors the system voltage over an extended length of time. If the ECM/PCM detects an excessively low system voltage, DTC P0562 will set.

This diagnostic procedure supports the following DTC

DTC P0562 System Voltage Low

System voltage is between 9.5-18 volts.

Conditions for Setting the DTC

The ECM/PCM detects a system voltage below 10.5 volts for 10 seconds.

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

1. The ECM/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 P0562

The engine control module (ECM)/powertrain control module (PCM) 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/PCM monitors the system voltage over an extended length of time. If the ECM/PCM detects an excessively high system voltage, DTC P0563 will set.

This diagnostic procedure supports the following DTC

DTC P0563 System Voltage High

System voltage is between 9.5-18 volts.

The ECM/PCM detects a system voltage above 17.5 volts for 10 seconds.

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

1. The ECM/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 P0563

The engine control module (ECM)/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 ECM/PCM applies a voltage to the voltage regulator. This signals the voltage regulator to turn the field circuit ON and OFF. When the ECM/PCM turns ON the high side driver, the voltage regulator turns ON the field circuit. When the ECM/PCM turns OFF the high side driver, the voltage regulator turns OFF the field circuit.

The ECM/PCM monitors the state of the generator turn ON signal circuit. With the engine running, the ECM/PCM should detect a high generator turn ON signal circuit, or when the charging system malfunctions. If the ECM/PCM detects a low generator turn ON signal circuit, DTC P0621 will set. When the DTC sets, the ECM/PCM will send a 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

1. No generator, crankshaft position (CKP) sensor, or camshaft position (CMP) sensor DTCs are set.
2. The engine is running.

The ECM detects a low signal voltage on the generator turn on signal circuit for at least 5 seconds.

1. The ECM/PCM sends a serial data message to the IPC to illuminate the charge indicator.
2. The ECM/PCM will not illuminate the malfunction indicator lamp (MIL).
3. The ECM/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 engine control module (ECM)/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 ECM/PCM uses the PWM signal input to determine the generator load on the engine. This allows the ECM/PCM to adjust the idle speed to compensate for high electrical loads.

The ECM/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 ECM/PCM should detect a duty cycle near 0 percent. However, when the engine is running, the duty cycle should be between 5-100 percent. The ECM/PCM monitors the PWM signal. If the ECM/PCM detects an out of range PWM signal, DTC P0622 will set. When the DTC sets, the ECM/PCM will send a 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) sensor, 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 sensor, or CMP sensor DTCs are set.
2. The engine speed is less than 3,000 RPM.

1. During the key ON test, the ECM/PCM detects a PWM signal greater than 65 percent for at least 5 seconds. OR
2. During the RUN test, the ECM/PCM detects a PWM signal less than 5 percent for at least 15 seconds.

1. The ECM/PCM sends a serial data message to the IPC to illuminate the charge indicator.
2. The ECM/PCM will not illuminate the malfunction indicator lamp (MIL).
3. The ECM/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 P0622

The engine control module (ECM)/powertrain control module (PCM) receives 2 ignition inputs from the ignition switch, ignition 1 signal, and ignition accessory signal. The ECM/PCM receives the crank input from a serial data message from the body control module (BCM). The ECM/PCM determines the state of the ignition switch based on these 3 inputs. If the ECM/PCM detects an improper ignition accessory signal, DTC P1633 will set.

This diagnostic procedure supports the following DTC

DTC P1633 Ignition 0 Switch Circuit

No serial data circuit problem.

The ECM/PCM detects an improper ignition accessory input voltage.

1. The ECM/PCM will not illuminate the malfunction indicator lamp (MIL).
2. The ECM/PCM will store conditions which were present when the DTC set as Failure Records 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 P1633

Symptoms - Engine Electrical

1. Perform «Control Module References»(/chevrolet/cobalt/i-2004-2010/remont/communication-devices/#computerintegrating-systems__control-module-references) in Computer/Integrating Systems 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»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) «Starting System Description and Operation»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__starting-system-description-and-operation) «Charging System Description and Operation (w/RVC)»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) «Charging System Description and Operation (w/o RVC)»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) «Load Shed System Description and Operation»(/chevrolet/cobalt/i-2004-2010/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»(/chevrolet/cobalt/i-2004-2010/remont/electrical-component-locations/#wiring-systems-electrical-power-management__checking-aftermarket-accessories) in Wiring Systems.
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 in Wiring Systems.

Symptom List

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

1. «Battery Inspection/Test»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system)
2. «Battery Electrical Drain/Parasitic Load Test»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system)
3. «Battery Common Causes of Failure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__battery-common-causes-of-failure)
4. «Charging System Test»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__charging-system-test)
5. «Charge Indicator Always On»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__charge-indicator-always-on)
6. «Charge Indicator Inoperative»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__charge-indicator-inoperative)
7. «Generator Noise Diagnosis»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system)
8. «Starter Solenoid Does Not Click»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__starter-solenoid-does-not-click)
9. «Starter Solenoid Clicks, Engine Does Not Crank»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system)
10. «Engine Cranks Slowly»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__engine-cranks-slowly)
11. «Starter Motor Noise Diagnosis»(/chevrolet/cobalt/i-2004-2010/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»(/chevrolet/cobalt/i-2004-2010/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»(/chevrolet/cobalt/i-2004-2010/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»(/chevrolet/cobalt/i-2004-2010/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

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»(/chevrolet/cobalt/i-2004-2010/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 the following table to determine the SOC according to the estimated battery temperature

Battery Charging

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.

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 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.

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 powertrain control module (PCM) or other electronic components.

Note. Refer to Fastener Notice in Cautions and Notices.

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»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .

J 38758 Parasitic Draw Test Switch. See Special Tools .

1. Rule out any possible obvious influences, such as customer error or aftermarket equipment.
2. Check 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»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Verify that the battery and charging system are in proper working order. Refer to «Battery Charging»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) and «Charging System Test»(/chevrolet/cobalt/i-2004-2010/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 «Control Module References»(/chevrolet/cobalt/i-2004-2010/remont/communication-devices/#computerintegrating-systems__control-module-references) in Computer/Integrating Systems for the system or modules description and operation.
6. Some systems and modules such as theft or remote keyless entry (RKE) will wake up due to an outside input. Refer to «Control Module References»(/chevrolet/cobalt/i-2004-2010/remont/communication-devices/#computerintegrating-systems__control-module-references) in Computer/Integrating Systems for the system or modules 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 minutes 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

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»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .
3. Turn the J 38758 knob to the OFF position. See «Special Tools»(/chevrolet/cobalt/i-2004-2010/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»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .
5. Turn the J 38758 knob to the ON position. See «Special Tools»(/chevrolet/cobalt/i-2004-2010/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 10-amp fused jumper wire to the test switch tool terminals.
9. Turn the J 38758 knob to the OFF position. See «Special Tools»(/chevrolet/cobalt/i-2004-2010/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 DMM to the 10A scale.
13. Connect the DMM to the test switch tool terminals.
14. Turn the J 38758 knob to the OFF position. See «Special Tools»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) . The current flows now through the DMM.
15. Wait 1 minute. Inspect 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»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) . The electrical current will now pass through the switch. Then switch the DMM down to the 2A scale for a more accurate reading when the J 38758 knob is turned OFF. See «Special Tools»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .
16. Turn the J 38758 knob to the OFF position. See «Special Tools»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) . Wait 15 minutes for most vehicles.
17. Inspect and record the current reading.
18. Note the battery reserve capacity (amp hour rating). Refer to «Battery Usage»(/chevrolet/cobalt/i-2004-2010/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 milliamp 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
20. Using the MIN/MAX function of the DMM, monitor the parasitic drain overnight or during the day. This will determine if something has been activated during that time frame.
21. 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»(/chevrolet/cobalt/i-2004-2010/remont/electrical-component-locations/#wiring-systems-electrical-power-management) in Wiring Systems 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. If it has been determined that the OnStar® system is the source of parasitic load.
22. 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.
23. When the cause of the excessive current drain has been located and repaired, remove the J 38758 . See «Special Tools»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system__special-tools) .
24. 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»(/chevrolet/cobalt/i-2004-2010/remont/electrical-component-locations/#wiring-systems-electrical-power-management) 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

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

1. 4: When testing the circuit for a high resistance, ensure to use the voltage drop test in the Circuit Testing procedure. If the circuit has more than more than a 0.5-volt drop when the starter is engaged then there is a high resistance.
2. 5: When testing the circuit for a high resistance, ensure to use the voltage drop test in the Circuit Testing procedure. If the circuit has more than a 0.5-volt drop when the starter is engaged, then there is a high resistance. Ensure when testing the engine ground to battery to connect the engine ground lead to the base of the starter.

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»(/chevrolet/cobalt/i-2004-2010/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»(/chevrolet/cobalt/i-2004-2010/remont/electrical-component-locations/#wiring-systems-electrical-power-management__circuit-testing) , «Wiring Repairs»(/chevrolet/cobalt/i-2004-2010/remont/electrical-component-locations/#wiring-systems-electrical-power-management__wiring-repairs) , «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/cobalt/i-2004-2010/remont/electrical-component-locations/#wiring-systems-electrical-power-management__testing-for-intermittent-conditions-and-poor) , and «Connector Repairs»(/chevrolet/cobalt/i-2004-2010/remont/electrical-component-locations/#wiring-systems-electrical-power-management__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 (2.2L (L61)) or Starter Motor Replacement (2.0L (LSJ)) .

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 3 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. Make sure the ignition switch is in the OFF position.
4. Disconnect the battery negative cable from the battery (2).

Scheme 10

Note. Refer to Fastener Notice in Cautions and Notices.

1. Connect the battery negative cable to the battery (2). Tighten: Tighten the bolt to 15 N.m (11 lb ft).
2. Reset the radio stations and the clock.

1. Disconnect the battery current sensor electrical connector (2).
2. Remove the battery negative cable from the vehicle. Refer to «Battery Negative Cable Replacement»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Remove the tape (3) securing the battery current sensor (1) to the negative battery cable (4).
4. Remove the battery current sensor (2) from the ground end of the negative battery cable (1).

Installation Procedure

1. Install the battery current sensor (2) by passing the ground end of the negative battery cable (1) through the sensor. Slide the current sensor to the battery end of the cable in order to encompass all ground wires attached to battery.
2. Wrap electrical tape (3) around the battery current sensor (1) in order to secure the battery current sensor to the negative battery cable (4).
3. Install the battery negative cable to the vehicle. Refer to «Battery Negative Cable Replacement»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Connect the battery current sensor electrical connector (2).

1. Disconnect the negative battery cable (1) from the negative battery post. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the negative battery cable bolt (2).
3. Disconnect the sensor connection (3).
4. Remove the ground cable from the vehicle, noting the routing for installation.

1. Connect the sensor (3).
2. Install the negative battery cable bolt (2). Tighten: Tighten the bolt to 20 N.m (15 lb ft).
3. Connect the negative battery cable (1). Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the negative battery cable from the battery. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Disconnect the positive battery cable nut (1) from the underhood junction block terminal.
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
4. Remove the positive battery cable nut (2).
5. Disconnect the positive battery cable (1) from the starter.
6. Remove the positive battery cable from the vehicle.

1. Place the battery cable in the vehicle using the original routing.
2. Connect the positive battery cable (1) to the starter and the positive cable nut (2). Tighten: Tighten the starter terminal nut to 17 N.m (13 lb ft).
3. Tape the positive battery cable to the negative battery cable near the transmission.
4. Lower the vehicle.
5. Connect the positive cable (2) to the underhood junction block.
6. Connect the positive battery cable nut (1) to the underhood junction block. Tighten: Tighten the bolt (2) to 17 N.m (13 lb ft).
7. Connect the negative battery cable to the battery. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the negative battery cable from the battery. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Disconnect the positive battery cable end (1) from the battery.
3. Disconnect the positive battery cable (3) from the connector (2).
4. Remove the underhood junction block. Refer to «Underhood Electrical Center or Junction Block Bracket Replacement»(/chevrolet/cobalt/i-2004-2010/remont/electrical-component-locations/#wiring-systems-electrical-power-management) in Wiring Systems.
5. Unseat the cable retainer from the underhood area near the LT shock tower.
6. Remove the rear seat cushion. Refer to «Seat Cushion Replacement - Rear»(/chevrolet/cobalt/i-2004-2010/remont/seats/#seat-system) in Seats.
7. Remove the drivers seat assembly. Refer to «Seat Replacement - Front Bucket»(/chevrolet/cobalt/i-2004-2010/remont/seats/#seat-system) in Seats.
8. Pull back the carpet and sound insulation padding in order to expose the battery positive cable. Refer to «Carpet Replacement»(/chevrolet/cobalt/i-2004-2010/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
9. Remove the battery cable clip (1) from the weld studs.
10. Remove the battery cable clip (2) from the floor plan.
11. Release all of the cable hold down clips (1) in the interior area of the floor pan.
12. Remove the battery cable from the body harness clips (1).
13. Remove the battery positive cable nut (1).
14. Remove the battery cable (2) from the junction block stud.
15. Remove the battery cable from the remaining body harness clips (2).
16. Pull the interior to engine compartment grommet (1) from the interior in order to release the battery cable from the vehicle.

1. Route the battery cable through the engine compartment pass through and up to the underhood junction.
2. Seat the interior to engine compartment grommet (1) by pulling from the engine compartment side of the battery cable.
3. Install the battery cable to the retaining clips (2).
4. Install the battery cable (2) to the junction block stud.
5. Install the battery cable nut (1). Tighten: Tighten the nut to 15 N.m (11 lb ft).
6. Install the battery cable to the body harness clips (1).
7. Route the battery cable along the floor pan and install the battery cable to all of the hold down clips (1).
8. Install the battery cable clip (2) to the floor pan.
9. Install the battery cable clips (1) to the floor pan studs.
10. Position the sound insulation and carpet to the interior. Refer to «Carpet Replacement»(/chevrolet/cobalt/i-2004-2010/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
11. Install the drivers seat assembly. Refer to «Seat Replacement - Front Bucket»(/chevrolet/cobalt/i-2004-2010/remont/seats/#seat-system) in Seats.
12. Install the rear seat cushion. Refer to «Seat Cushion Replacement - Rear»(/chevrolet/cobalt/i-2004-2010/remont/seats/#seat-system) in Seats.
13. Secure the cable retainer to the underhood area near the LT shock tower.
14. Install the underhood junction block. Refer to «Underhood Electrical Center or Junction Block Bracket Replacement»(/chevrolet/cobalt/i-2004-2010/remont/electrical-component-locations/#wiring-systems-electrical-power-management) in Wiring Systems.
15. Connect the positive battery cable end (1) to the battery. Tighten: Tighten the positive battery terminal bolt (1) to 15 N.m (11 lb ft).
16. Connect the positive cable (3) to the connector (2).
17. Connect the negative battery cable (1) to the battery. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the negative battery cable (2). Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Disconnect the positive battery cable (1).
3. Remove the battery hold down retainer bolt (1).
4. Remove the strap (2).
5. Remove the retainer (3).
6. Remove the battery (4).

1. Install the battery to the battery tray.
2. Install the battery (4).
3. Install the retainer (3).
4. Install the strap (2).
5. Install the battery hold down retainer bolt (1). Tighten: Tighten the battery hold down retainer bolt to 25 N.m (18 lb ft).
6. Connect the positive battery cable (1). Tighten: Tighten the battery positive cable terminal bolt to 15 N.m (11 lb ft).
7. Connect the negative battery cable (2). Tighten: Tighten the battery negative cable terminal bolt to 15 N.m (11 lb ft).

1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
3. Disconnect the electrical connectors (3, 4, 5) from the starter.
4. Remove the starter bolts.
5. Remove the starter.

1. Install the starter.
2. Install the starter bolts. Tighten: Tighten the starter bolts to 40 N.m (30 lb ft).
3. Connect the electrical connectors (4, 5) to the starter. Tighten: Tighten the battery terminal nut to 17 N.m (13 lb ft).
4. Connect the S-terminal connector (3) to the starter. Tighten: Tighten the battery terminal nut to 3 N.m (27 lb in).
5. Lower the vehicle.
6. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
3. Remove the intercooler pump outer bracket.
4. Disconnect the electrical connectors (3, 4, 5) from the starter.
5. Remove the starter bolts.
6. Remove the starter.

1. Install the starter.
2. Install the starter bolts. Tighten: Tighten the starter bolts to 50 N.m (37 lb ft).
3. Connect the electrical connectors (4, 5) to the starter. Tighten: Tighten the battery terminal nut to 11 N.m (97 lb in).
4. Connect the S-terminal connector (3) to the starter. Tighten: Tighten the battery terminal nut to 3 N.m (27 lb in).
5. Install the intercooler pump outer bracket. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
6. Lower the vehicle.
7. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/cobalt/i-2004-2010/remont/mechanical/#engine-mechanical-22l-l61) in Engine Mechanical - 2.2L (L61).
3. Remove the air cleaner outlet resonator. Refer to «Air Cleaner Outlet Resonator Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) in Engine Controls - 2.2L (L61).
4. Disconnect the generator connectors.
5. Remove the generator bolts.
6. Remove the generator from the vehicle.

1. Position the generator on the engine.
2. Install the generator bolts. Tighten: Tighten the generator bolts to 22 N.m (16 lb ft).
3. Connect the positive battery harness to the generator battery terminal. Tighten: Tighten the generator terminal nut to 20 N.m (15 lb ft).
4. Connect the generator harness connectors.
5. Install the air cleaner outlet resonator. Refer to «Air Cleaner Outlet Resonator Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) in Engine Controls - 2.2L (L61).
6. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/cobalt/i-2004-2010/remont/mechanical/#engine-mechanical-22l-l61) in Engine Mechanical - 2.2L (L61).
7. Connect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Disconnect negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/cobalt/i-2004-2010/remont/mechanical/#engine-mechanical-20l) in Engine Mechanical - 2.0L (LSJ).
3. Remove the supercharger. Refer to «Supercharger Replacement»(/chevrolet/cobalt/i-2004-2010/remont/mechanical/#engine-mechanical-20l) in Engine Mechanical - 2.0L (LSJ).
4. Remove the oil level indicator tube bolt and reposition the tube slightly for clearance.
5. Disconnect the generator connectors.
6. Remove the generator bolts.
7. Remove the generator from the vehicle.

1. Position the generator on the engine.
2. Install the generator bolts. Tighten: Tighten the generator bolts to 25 N.m (18 lb ft).
3. Connect the positive battery harness to the generator battery terminal. Tighten: Tighten the generator terminal nut to 20 N.m (15 lb ft).
4. Connect the generator harness connectors.
5. Position the oil level indicator tube into the correct installed position and install the retaining bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
6. Install the supercharger. Refer to «Supercharger Replacement»(/chevrolet/cobalt/i-2004-2010/remont/mechanical/#engine-mechanical-20l) in Engine Mechanical - 2.0L (LSJ).
7. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/cobalt/i-2004-2010/remont/mechanical/#engine-mechanical-20l) in Engine Mechanical - 2.0L (LSJ).
8. Connect the battery negative cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) .

Scheme 11

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 12

Battery Ratings

A battery may have 3 ratings

1. Amp hour
2. Reserve capacity
3. Cold cranking amperage

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

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

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.

Cold Cranking Amperage

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 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 function of the acid concentration and the internal resistance of the battery, and is estimated by reading the battery open circuit voltage when the battery has been at rest for several hours.

The SOC can be used as a diagnostic tool to tell the customer or the dealer the condition of the battery. Throughout key-on, the 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 electrical power management (EPM). The second section describes charging system operation. The third section describes the instrument panel cluster (IPC) operation of the charge indicator, driver information center (DIC) 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 amount of current provided to the rotor. If the generator has field control circuit failure, the generator defaults to an output voltage of 13.8 volts.

Body Control Module (BCM)

The body control module (BCM) is a GM LAN device. It communicates with the engine control module (ECM) and the instrument panel cluster (IPC) for electrical power management (EPM) operation. The BCM determines the output of the generator and sends the information to the ECM for control of the generator field control circuit. It monitors the generator field duty cycle signal circuit information sent from the ECM for control of the generator. It monitors a battery current sensor, the battery positive voltage circuit, and estimated battery temperature to determine battery state-of-charge (SOC). The BCM performs idle boost and load management operations.

Battery Current Sensor

The battery current sensor is a serviceable component that is connected to 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)

The ECM 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. The ECM will override the BCM control of the generator when one of the following conditions are met

1. The engine cooling fans are on high speed.
2. There is a high fuel demand.
3. The calculated ambient air temperature is less that 0°C (32°F).

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 (DIC) 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 6 modes of operation and they include

1. Charge Mode
2. Fuel Economy Mode
3. Voltage Reduction Mode
4. Start-up Mode
5. Windshield Deice Mode
6. Battery Sulfation Mode

The engine control module (ECM) controls the generator through the generator L-terminal control 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 (w/RVC)

The generator provides a feedback signal of the generator voltage output through the generator field duty cycle signal circuit to the ECM. This information is sent to the body control module (BCM). The signal is a 12-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 interpreted fuel rate is greater than 21 g/s and the throttle position is greater than 90 percent.
2. The headlamps are ON, low or high beam.
3. The wipers are ON for more than 8 seconds.
4. The electric cooling fans are on high speed.
5. The rear defogger is ON.

Once one of these conditions are met, the generator battery control module will set the targeted generator output voltage to 13.4 volts and then ramp that voltage up to 14.5 volts at a rate of 50 mV per second.

Fuel Economy Mode

The BCM will enter Fuel Economy Mode when the calculated ambient air temperature is above 0°C (32°F), the calculated battery current is less than 15 amps and greater than -8 amps, and the battery state-of-charge (SOC) is greater than 80 percent. Its targeted generator output voltage is 13 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 calculated ambient air temperature is above 0°C (32°F); the calculated battery current is less than 2 amps and greater than -7 amps, 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.

Start-up Mode

After the engine has started, the BCM sets a targeted generator output voltage of 14.5 volts for 20 seconds.

Windshield Deice Mode

After the engine has run for more than 10 seconds, the BCM sets a targeted generator output voltage of 13.8 volts if the calculated ambient air temperature is less that 0°C (32°F). The BCM will stay in this mode until the engine coolant temperature (ECT) reaches 75°C (167°F) for 10 minutes.

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 set a targeted output voltage of 13.8 volts for 5 minutes. 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 engine control module (ECM) detects that the generator output is less than 11 volts or greater than 16 volts. The IPC receives a serial data message from the ECM requesting illumination.
2. The IPC determines that the system voltage is less than 11 volts or greater than 16 volts for more than 30 seconds. The IPC receives a serial data 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 BCM and the ECM will send a serial data 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 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 driver information center (DIC) when the vehicle enters a load shed 2 event. Refer to for load shed 2 setting criteria.

The generator features the following major components

1. The dual "Y" stator
2. The rectifier bridge
3. The rotor with slip rings and brushes
4. A decoupler pulley
5. Dual internal fans
6. The regulator

The pulley and the fan cool the slip ring and the frame.

The generator features permanently lubricated bearings. Service should only include tightening of mount components. Otherwise, replace the generator as a complete unit.

Regulator

The voltage regulator controls the rotor field current in order to limit the system voltage. When the field current is ON, the regulator switches the current ON and OFF at a rate of 400 cycles per second in order to perform the following functions

1. Radio noise control
2. Obtain the correct average current needed for proper system voltage control

At high speeds, the on-time may be 10 percent with the off-time at 90 percent. At low speeds, the on-time may be 90 percent and the off-time 10 percent.

The generator provides voltage to operate the vehicle's electrical system and to charge its battery. A magnetic field is created when current flows through the rotor. This field rotates as the rotor is driven by the engine, creating an AC voltage in the stator windings. The AC voltage is converted to DC by the rectifier bridge and is supplied to the electrical system at the battery terminal.

When the engine is running, the generator turn-on signal is sent to the generator from the powertrain control module (PCM), turning ON the regulator. The generator's voltage regulator controls current to the rotor, thereby controlling the output voltage. The rotor current is proportional to the electrical pulse width supplied by the regulator. When the engine is started, the regulator senses generator rotation by detecting AC voltage at the stator through an internal wire. Once the engine is running, the regulator varies the field current by controlling the pulse width. This regulates the generator output voltage for proper battery charging and electrical system operation. The generator F-terminal is connected internally to the voltage regulator and externally to the PCM. When the voltage regulator detects a charging system problem, it grounds this circuit to signal the PCM that a problem exists. The PCM monitors the generator field duty cycle signal circuit.

Charging System Indicator

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

1. The powertrain control module (PCM) detects that the generator output is less than 11 volts or greater than 16 volts. The IPC receives a serial data message from the PCM requesting illumination.
2. The IPC determines that the system voltage is less than 11 volts or greater than 16 volts. The IPC receives a serial data message from the body control module (BCM) indicating the system voltage.
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.

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 START 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.

Moving the ignition switch to the START position signals the body control module (BCM) through discrete inputs from the ignition transducer that engine crank has been requested. The BCM verifies that theft is not active and sends a serial data message to the engine control module (ECM)/powertrain control module (PCM) requesting engine start. The ECM/PCM receives a 12-volt signal from the park/neutral position (PNP) switch or clutch pedal start switch notifying that it is safe to start the engine. There is a splice on this circuit in the fuse block-underhood that supplies power for the starter relay coil. The starter relay coil control circuit is then grounded by the ECM/PCM closing the switch in the starter relay suppling 12 volts to the S-terminal of the starter. Ground is supplied through the engine block.

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 13

Scheme 14

See also:
• Diagnostic System Check - Vehicle
• DTC Symptom Description
• Body Control System Schematics
• Testing for Intermittent Conditions and Poor Connections
• Circuit Testing
• Wiring Repairs
• Connector Repairs
• Control Module References
• Power Distribution Schematics
• Power and Grounding Connector End Views
• Inline Harness Connector End Views
• Powertrain Control Module (PCM) Connector End Views
• Engine Control Module (ECM) Connector End Views
• Engine Controls Schematics
• Engine Controls Schematics
• Checking Aftermarket Accessories
• Battery Disconnect Caution
• Fastener Notice
• Body Control System Description and Operation
• Drive Belt Replacement
• Drive Belt Replacement
• Drive Belt Tensioner Diagnosis
• Park/Neutral Position (PNP) Switch Replacement
• Engine Will Not Crank - Crankshaft Will Not Rotate
• SIR Caution
• Lifting and Jacking the Vehicle
• Seat Cushion Replacement - Rear
• Carpet Replacement
• Battery Inspection/Test
• Engine Electrical Connector End Views
• Charging System Test
• Starting System Description and Operation
• Battery Common Causes of Failure
• Charge Indicator Always On
• Charge Indicator Inoperative
• Starter Solenoid Does Not Click
• Engine Cranks Slowly
• Special Tools
• Battery Usage
• Generator Usage