Battery, Charging System and Starting System: Other Chevrolet Silverado Classic 1500 HD

Battery Usage (HP2)

Battery Usage (HP2)

Battery Usage (Non HP2)

Battery Usage (Non HP2)

Generator Usage

Generator Usage

Scheme 7

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Scheme 9

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Scheme 13

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Scheme 25

Auxiliary Battery Relay Connector Part Information (TP2)

Auxiliary Battery Relay Connector Terminal Identification (TP2)

Scheme 26

Battery Cut Off Switch Connector Part Information (HP2)

Battery Cut Off Switch Connector Terminal Identification (HP2)

Scheme 27

Clutch Pedal Position (CPP) Switch Connector Part Information

Clutch Pedal Position (CPP) Switch Connector Terminal Identification

Scheme 28

Current Sensor Connector Part Information (HP2)

Current Sensor Connector Terminal Identification (HP2)

Scheme 29

Energy Storage Box (ESB) Fan Connector Part Information (HP2)

Energy Storage Box (ESB) Fan Connector Terminal Identification (HP2)

Scheme 30

Energy Storage Control Module (ESCM) C1 Connector Part Information (HP2)

Energy Storage Control Module (ESCM) C1 Connector Terminal Identification (HP2)

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Energy Storage Control Module (ESCM) C2 Connector Part Information (HP2)

Energy Storage Control Module (ESCM) C2 Connector Terminal Identification (HP2)

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Energy Storage Control Module (ESCM) C3 Connector Part Information (HP2)

Energy Storage Control Module (ESCM) C3 Connector Terminal Identification (HP2)

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Generator Connector Part Information - Gas (10 Series Except HP2)

Generator Connector Terminal Identification - Gas (10 Series Except HP2)

Scheme 34

Generator Connector Part Information - Gas (6.0L w/MT1)

Generator Connector Terminal Identification - Gas (6.0L w/MT1)

Scheme 35

Generator Connector Part Information (20/30 Series)

Generator Connector Terminal Identification (20/30 Series)

Scheme 36

Generator Connector Part Information - Left (K65/8X5)

Generator Connector Terminal Identification - Left (K65/8X5)

Generator - Right - Diesel

Generator Connector Part Information - Right (Diesel)

Generator Connector Terminal Identification - Right (Diesel)

Scheme 37

Generator Battery Control Module Connector Part Information (10 Series Except HP2)

Generator Battery Control Module Connector Terminal Identification (10 Series Except HP2)

Scheme 38

Hood Ajar Switch Connector Part Information (HP2)

Hood Ajar Switch Connector Terminal Identification (HP2)

Scheme 39

Hybrid Control Module (HCM) Connector Part Information (HP2)

Hybrid Control Module (HCM) Connector Terminal Identification (HP2)

Scheme 40

Starter/Generator Control Module (SGCM) C1 Connector Part Information (HP2)

Starter/Generator Control Module (SGCM) C1 Connector Terminal Identification (HP2)

Scheme 41

Starter/Generator Control Module (SGCM) C2 Connector Part Information (HP2)

Starter/Generator Control Module (SGCM) C2 Connector Terminal Identification (HP2)

Scheme 42

Starter/Generator Control Module (SGCM) C3 Connector Part Information (HP2)

Starter/Generator Control Module (SGCM) C3 Connector Terminal Identification (HP2)

Scheme 43

Starter/Generator Control Module (SGCM) C4 Connector Part Information (HP2)

Starter/Generator Control Module (SGCM) C4 Connector Terminal Identification (HP2)

Scheme 44

Starter/Generator Control Module (SGCM) C5 Connector Part Information (HP2)

Starter/Generator Control Module (SGCM) C5 Connector Terminal Identification (HP2)

Scheme 45

Temperature Sensor Connector Part Information - Battery 1 (HP2)

Temperature Sensor Connector Terminal Identification - Battery 1 (HP2)

Temperature Sensor - Battery 2 (HP2)

Temperature Sensor Connector Part Information - Battery 2 (HP2)

Temperature Sensor Connector Terminal Identification - Battery 2 (HP2)

Temperature Sensor - Battery 3 (HP2)

Temperature Sensor Connector Part Information - Battery 3 (HP2)

Temperature Sensor Connector Terminal Identification - Battery 3 (HP2)

Scheme 46

Voltage Sensor 1 Connector Part Information (HP2)

Voltage Sensor 1 Connector Terminal Identification (HP2)

Voltage Sensor - 2 (HP2)

Voltage Sensor 2 Connector Part Information (HP2)

Voltage Sensor 2 Connector Terminal Identification (HP2)

Voltage Sensor - 3 (HP2)

Voltage Sensor 3 Connector Part Information (HP2)

Voltage Sensor 3 Connector Terminal Identification (HP2)

Voltage Sensor - 4 (HP2)

Voltage Sensor 4 Connector Part Information (HP2)

Voltage Sensor 4 Connector Terminal Identification (HP2)

Intermittent

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

Tools Required

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»(ref-277854-S13861956242008012100000) .

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 state-of-charge 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. 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 ECM/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 Fuse Block - 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 (Non-HP2)»(ref-277854-S33094842442008012100000) or «Battery Inspection/Test (HP2)»(ref-277854-S32657770072008012100000) .

Battery Charging (HP2)

Tools Required

1. J 42000 Battery Tester. See «Special Tools»(ref-277854-S13861956242008012100000) .
2. J 42634 Battery Module Charger or equivalent

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 state-of-charge 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. As the battery warms, the charging current will increase.

Charging Procedure Individual Panasonic Batteries

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. Refer to Fastener Notice .

Automatic Battery Charger

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 and the negative charger lead to the negative battery terminal.
4. Turn ON the charger and set to the automatic setting.
5. Inspect the battery every half hour after starting the battery charger.
6. Charge the battery until the until the taper-rate charger indicates that the battery is fully charged.
7. 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.
8. After charging, test the battery. Refer to «Battery Inspection/Test (Non-HP2)»(ref-277854-S33094842442008012100000) or «Battery Inspection/Test (HP2)»(ref-277854-S32657770072008012100000) .

Manual Battery Charger

1. If charging with a manual battery charger use the following procedure to ensure proper results.
2. Use of any boost charging method will cause damage to the Panasonic Battery.
3. Monitor battery charging every 30 minutes.

Panasonic Battery Charge Procedure - Manual Charger

After charging, test the battery. Refer to Battery Inspection/Test (Non-HP2) or Battery Inspection/Test (HP2) .

J 38758 Parasitic Draw Test Switch. See Special Tools .

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 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»(ref-277884-S11099941162008012100000) .

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 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 (Non-HP2) or Battery Inspection/Test (HP2) .

In order to maintain a 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 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 (HP2)

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.

This vehicle has a 12-volt positive, negative ground electrical system. Do not try to jump start a vehicle if you are unsure of the other vehicle's positive voltage or ground position. The booster battery and the discharged battery should be treated carefully when using jumper cables.

1. Position the vehicle with the booster battery so that the jumper cables will comfortably reach the battery of the other vehicle. Do not let the 2 vehicles touch. Make sure that the jumper cables do not have loose clamps or missing insulation.
2. Perform the following steps on both vehicles: Place the automatic transmission in PARK. Block the wheels. Set the parking brake. Turn OFF all electrical loads that are not needed. Leave the hazard flashers ON. Turn OFF the ignition switch.
3. Attach the end of one jumper cable to the positive terminal or remote stud of the discharged battery.
4. Attach the other end of the first cable to the positive terminal of the booster battery.
5. Attach one end of the remaining jumper cable to the negative terminal of the booster battery.
6. Make the final connection of the negative jumper cable to the block or suitable bracket connected directly to the block, away from the battery.
7. Turn and hold key in the CRANK position for 5 seconds.
8. Turn the key to the OFF position. The starter generator control module (SGCM) will command the 14-volt to 42-volt power to charge the energy storage box (ESB) batteries as long as battery voltage is greater the 11.2 volts.
9. Reverse the steps exactly when removing the jumper cables. The negative battery cable must first be disconnected from the engine that was jump started.

Jump Starting in Case of Emergency (Non HP2)

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.

This vehicle has a 12-volt positive, negative ground electrical system. Do not try to jump start a vehicle, if you are unsure of the other vehicle's positive voltage or ground position. The booster battery and the discharged battery should be treated carefully when using jumper cables.

1. Position the vehicle with the booster battery so that the jumper cables will comfortably reach the battery of the other vehicle. Do not let the 2 vehicles touch. Make sure that the jumper cables do not have loose clamps or missing insulation.
2. Perform the following steps on both vehicles: Place the automatic transmission in PARK. Block the wheels. Set the parking brake. Turn off all electrical loads that are not needed. Leave the hazard flashers ON. Turn OFF the ignition switch.
3. Attach the end of one jumper cable to the positive terminal of the discharged battery.
4. Attach the other end of the first cable to the positive terminal of the booster battery.
5. Attach one end of the remaining jumper cable to the negative terminal of the booster battery.
6. Make the final connection of the negative jumper cable to the block or suitable bracket connected directly to the block, away from the battery.
7. Start the engine of the vehicle that is providing the jump start and turn off all electrical accessories. Raise the engine RPM to approximately 1,500 RPM.
8. Crank the engine of the vehicle with the weak battery. If the engine does not crank or cranks too slowly, perform the following steps: Turn the ignition OFF. Allow the booster vehicle engine to run at approximately 1,500 RPM for 5 minutes. Attempt to start the engine of the vehicle with the discharged battery.
9. Reverse the steps exactly when removing the jumper cables. The negative battery cable must first be disconnected from the engine that was jump started.

Charge Indicator Always On

Charge Indicator Always On

Charge Indicator Inoperative

Charge Indicator Inoperative

Starter Solenoid Does Not Click (w/Allison)

Starter Solenoid Does Not Click (w/Allison)

Starter Solenoid Does Not Click (w/o Allison)

Starter Solenoid Does Not Click (w/o Allison)

Starter Solenoid Clicks, Engine Does Not Crank

Starter Solenoid Clicks, Engine Does Not Crank

Engine Cranks Slowly

Perform the following checks

1. Battery-Battery Inspection/Test. Refer to «Battery Inspection/Test (Non-HP2)»(ref-277854-S33094842442008012100000) or «Battery Inspection/Test (HP2)»(ref-277854-S32657770072008012100000) .
2. Wiring- Inspect the wiring for damage. Inspect all connections to the starter motor, solenoid, battery, and all ground connections. Refer to «Circuit Testing»(ref-277884-S17422072462008012100000) , «Wiring Repairs»(ref-277884-S08861102212008012100000) , «Testing for Intermittent Conditions and Poor Connections»(ref-277884-S20700666652008012100000) and «Connector Repairs»(ref-277884-S12371167392008012100000) .
3. Engine-Make sure the engine is not seized. Refer to «Symptoms - Engine Mechanical»(ref-277938-S33875885592008012100000) .

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 (4.3L) or Starter Motor Replacement (4.8L, 5.3L, and 6.0L) or Starter Motor Replacement (8.1L) or Starter Motor Replacement (6.6L) .

Battery Ratings

A battery has 2 ratings

1. Reserve capacity
2. 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 (HP2) or Battery Usage (Non HP2) .

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 is the minimum amperage necessary to maintain 7.2 volts for 30 seconds at -18°C (0°F). Refer to Battery Usage (HP2) or Battery Usage (Non HP2) for the cold cranking amperage rating for this vehicle.

Auxiliary Battery

Auxiliary batteries are an available option on vehicles where many accessories can be utilized such as TVs, radios, lights, computers, etc. The charging of these batteries is explained in charging system description and operation. Also, the auxiliary battery is only for accessory use and not part of the starting system.

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.

Generator Battery Control Module

The generator battery control module is a class 2 device. It communicates with the powertrain control module (PCM), instrument panel cluster and the body control module for electrical power management (EPM) operation. It is a serviceable component that is connected to the negative battery cable at the battery. It directly controls the generator field control circuit, charge indicator control, input to the generator. It continuously monitors the generator field duty cycle signal circuit and the battery voltage. If the generator battery control module loses communication with the PCM, the default voltage will be set to 13.8 volts and the module will set U1016. If the generator battery control module loses communication with the body control module (BCM), the module will set U1064.

Powertrain Control Module (PCM)

The PCM provides information over the class 2 serial data circuit to the generator battery control module. The generator battery control module monitors the following data parameters provided by the PCM

1. Intake air temperature
2. Fuel grams per second
3. Throttle position
4. Engine cooling fan speed
5. Engine coolant temperature
6. Exterior Environment - Outside Air Temperature

The generator battery control module uses these data parameters for different charging system modes depending on the required voltage needed.

Instrument Panel Cluster (IPC)

The instrument panel cluster (IPC) provides a means of customer notification in case of a failure. There are two means of notification, a battery charge indicator and a driver information center message of SERVICE CHARGING SYSTEM FAILURE and CHARGING SYSTEM FAULT.

Charge Mode

The generator battery control module will enter Charge Mode when at least one of the following conditions is met

1. The electric cooling fans are on high speed.
2. The rear defogger is ON.
3. The battery state of charge is less than 80 percent.
4. The battery current is not between -8 and 15 amps.
5. The estimated ambient air temperature is less than 0°C.
6. DTC B1516 is set.

Once one of these conditions are met the generator battery control module will set the targeted generator output voltage to the nominal optimum battery voltage which is from 13.9-15.5 volts, the voltage set point is based on the batteries state of charge and estimated battery temperature. The battery voltage ramps up to the targeted set point at a rate of 20 mV per second.

Fuel Economy Mode

The generator battery control module will enter Fuel Economy Mode when all of the following conditions are true

1. Estimated ambient air temperature is equal to or greater than 0°C (32°F).
2. The calculated battery current is less than 15 amperes and greater than - 8 amperes.
3. The battery state of charge is greater than or equal to 80 percent.
4. The rear defoggers are turned OFF.
5. The electric cooling fans are on low speed or OFF.

The targeted generator output voltage is 13 volts. The generator battery control module will exit this mode once the criteria are met for Charge Mode or it will boost voltage to a pre-determined set point for the fuel pump, headlamps, or windshield wipers.

Voltage Reduction Mode

The generator battery control module 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 amperes and greater than -7 amperes, the generator field duty cycle is less than 99 percent. The rear defoggers are turned OFF, and the electric cooling fans are on low speed or OFF. Its targeted generator output voltage is 87 percent of the Charge Mode set point but limited to 12.9 volts. The generator battery control module will exit this mode once the criteria are met for Charge Mode or it will boost voltage to a pre-determined set point for the fuel pump, headlamps, or windshield wipers.

Start Up Mode

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

Headlamp Mode

The generator battery control module will enter the Headlamp Mode when the headlamps, low or high beams, are turned ON. The voltage will ramp up or down to 14.5 volts at a rate of 10 mV/second. The module will exit this mode once the headlamps are turned OFF and enter Charge Mode, Fuel Economy Mode, or Voltage Reduction Mode.

Battery Sulfation Mode

The generator battery control module will enter this mode when the interpreted generator output voltage is less than 13.2 volts for 45 minutes. Once in this mode the generator battery control module will set the targeted output voltage to the nominal optimum battery voltage, see Charge Mode, for 3 minutes. The generator battery control module will then determine which mode to enter depending on vehicle conditions.

Windshield Wiper Voltage Boost Mode

When the generator battery control module is in Fuel Economy Mode or Voltage Reduction Mode, the module will boost battery voltage to 14.5 volts when the windshield wipers are ON, intermittent, low, or high speed, after 8 seconds. The voltage will ramp to 14.5 volts at a rate of 50 mV/second. The module will exit this mode once the Windshield Wipers are OFF for 5 seconds and the module will enter Charge Mode, Fuel Economy Mode, or Voltage Reduction Mode.

Fuel Pump Voltage Boost Mode

When the generator battery control module is in Fuel Economy Mode or Voltage Reduction Mode, the module will immediately boost battery voltage to 13.4 volts when the instantaneous fuel flow is greater than 21k grams/second and the throttle position sensor pedal position is greater than 90 percent. The module will exit this mode once the instantaneous fuel flow is less than 5k grams/second and enter Charge Mode, Fuel Economy Mode, or Voltage Reduction Mode.

De-Ice Voltage Boost Mode

The generator battery control module will enter De-Ice Voltage Boost Mode when the estimated ambient air temperature is less than or equal to -1°C and the engine coolant temperature is less than or equal to 75°C. The module will be in Charge Mode if the above conditions are true. Once the engine coolant temperature becomes greater than 75°C, the module will remain in Charge Mode or enter Fuel Economy Mode or Voltage Reduction Mode based on the vehicle conditions.

Charging System Failure

The generator battery control module will send a class 2 message to the IPC for the CHARGING SYSTEM FAILURE message to be displayed. It is commanded ON when DTC B1487 sets. The message is turned off when the conditions for clearing the DTC have been met and after an ignition cycle.

Service Charging System

The generator battery control module will send a class 2 message to the IPC for the SERVICE CHARGING SYSTEM message to be displayed. It is commanded ON when DTC B1390, B1488, B1492, or B1516 sets. The message is turned off when the conditions for clearing the DTC have been met and after an ignition cycle.

The AD-230 and AD-244 generators are non-repairable. They are electrically similar to earlier models. The generators feature the following major components

1. The delta stator
2. The rectifier bridge
3. The rotor with slip rings and brushes
4. A conventional pulley
5. Dual internal fans
6. A voltage regulator

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

The AD stands for air-cooled dual internal fan; the 2 is an electrical design designator; the 30/44 denotes the outside diameter of the stator laminations in millimeters, over 100 millimeters. The generators is rated at 102 and 130 amperes respectively.

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

Regulator

The voltage regulator controls the field current of the rotor in order to limit system voltage. 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.

Auxiliary Battery Charging

The auxiliary battery is charged in the same manner as the primary battery with the ignition switch in the run position and the engine running. The system contains the following components

1. Auxiliary battery.
2. Auxiliary battery relay.
3. Mega fuse.
4. Junction block battery cable.
5. Associated wiring.

The auxiliary battery relay coil is energized with the engine running through the fuse block and wiring, thus closing the relay contacts which allow the battery to be charged from the vehicle's generator via the battery junction block. The auxiliary battery relay is permanently grounded so any time the ignition switch is in the run position the relay will be energized.

The auxiliary battery is only used for accessories and is not part of the vehicle starting system. However if the primary battery fails and in need of an jump start, follow the service information for Jump Starting In Case Of Emergency using appropriate battery jumper cables.

Charging System Indicator

The IPC illuminates the charge indicator in the message center when the following occurs

1. The 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 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 class 2 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.

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.

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

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

Electrical Power Management Description and Operation