GM Service Manual Online
For 1990-2009 cars only
Table 1: Scan Tool Data Parameters
Table 2: Scan Tool Output Controls

The Drive Motor Generator Battery Control Module Scan Tool Data List contains all Hybrid Battery related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.

Use the scan tool data values under the following conditions:

    • The Diagnostic System Check - Vehicle is complete.
    • The On-Board Diagnostics are functioning properly.
    • There are no diagnostic trouble codes (DTCs) present.

Important: Do not use a scan tool that displays faulty data. Report the condition to the scan tool manufacturer. The use of a faulty scan tool can result in misdiagnosis and the unnecessary replacement of parts.

Only the parameters listed below are referenced in this manual for diagnosis. If a scan tool displays other parameters, those values are not recommended by General Motors for use in diagnosis.

If all values are within the expected range described below, refer to Symptoms - Hybrid Energy Storage for diagnosis.

The scan tool values from a properly running vehicle may be used for comparison with the vehicle you are diagnosing. The values below represent a typical display recorded from a properly functioning system.

Scan Tool Data Parameters

Parameter

System State

Expected Value

Description

Operating Conditions: Engine at idle, upper radiator hose hot, closed throttle, transmission in Park, closed loop operation, accessories OFF, brake pedal not applied, Hood Open, State of charge 60-80 percent.

300V Isolation Test Conditions Met

Yes/No

No

This parameter displays the status of the high voltage (HV) system as determined by the battery energy control module (BECM). This parameter indicates if the isolation test will run at the next High voltage power down cycle. Should display "Yes" after the ignition key is cycled to "Off" and before the isolation test runs.

300V Isolation Test Status

Not Run/In Progress/Passed/Failed

Passed or In Progress

This parameter displays the status of the "300V Isolation Test" diagnostic after running during normal vehicle operation or after running the special functions device control located under the battery energy control module (BECM) menu. This parameter can display Not Run, In Progress, Passed, or Failed.

Air Bags Deployed

Yes/No

No

This parameter displays information about contactor open reasons as determined by the battery energy control module (BECM). "Yes" indicates that an airbag deployment or high voltage circuit impact detection (HVCID) sensor activation has occurred.

Calc. Hybrid Batt. Current

amps

-2.0 to +2.0 amps

This parameter displays the hybrid battery current as determined by the battery energy control module (BECM). This is a discreet input to the BECM from the current sensor located in the drive motor generator battery. The BECM displays this current sensor parameter in Amps. This is a signed value. "+" sign represents energy being used from the hybrid battery or discharge and "-" sign represents energy being provided back to the hybrid battery or charge.

Calc. Hybrid Batt. Resistance

Ohms

0.48 ohms

This parameter displays the total impedance (in ohms) of the hybrid battery, as calculated by the battery energy control module (BECM). The BECM uses all 20 hybrid battery resistance measurement values in this calculation.

Contactor Commanded Open

Yes/No

No

This parameter displays information about the high voltage contactor commanded position as determined by the battery energy control module (BECM). "Yes" indicates that the BECM is commanding the contactors to open.

Contactor Sys. Req. Signal

Open/Closed

Closed

This parameter displays the requested contactor state command from the hybrid powertrain control module to the battery energy control module (BECM) over GM Lan for the hybrid battery contactor relay control as determined by the BECM. This can Display open or closed.

Contactor Sys. Req. CKT Command

%

30

This parameter displays the discrete PWM command from the hybrid powertrain control module for the hybrid battery contactor control as determined by the battery energy control module (BECM).

Contactor System Status

Open/Closed/Precharging/Precharge Failed/Precharge Inhibit

Closed

This parameter displays the status of the hybrid battery contactor system as determined by the battery energy control module (BECM). The status can be displayed as open, closed, precharging, precharge failed or precharge inhibit.

Control Module Voltage

Yes/No

No

This parameter displays information about contactor open reasons as determined by the battery energy control module (BECM). "Yes" indicates that control module voltage supply is high.

Control Module Voltage

Volts

13.7-14.5 volts

This parameter displays the value of the input voltage used to power up the battery energy control module (BECM), as measured by the BECM.

Current Sen. High Range

Amps

+2.0 to -2.0

The hybrid battery current sensor has 3 measurements ranges. This parameter displays the hybrid battery current sensor high range value in Amps as determined by the battery energy control module (BECM). The high range current sensor displays a value between -250 and +250 amps.

Current Sen. Low Range

Amps

+2.0 to -2.0

The hybrid battery current sensor has 3 measurements ranges. This parameter displays the hybrid battery current sensor low range value in Amps as determined by the battery energy control module (BECM). The low range current sensor displays a value between -22 and +22 amps. If current levels exceed this range, the value will be saturated at -22 or +22 amps.

Current Sen. Medium Range

Amps

+2.0 to -2.0

The hybrid battery current sensor has 3 measurements ranges. This parameter displays the hybrid battery current sensor medium range value in Amps as determined by the battery energy control module (BECM). The medium range current sensor displays a value between -52 and +52 amps. If current levels exceed this range, the value will be saturated at -52 or +52 amps.

HVIC Fault

Yes/No

No

This parameter displays information about contactor open reasons as determined by the battery energy control module (BECM). "Yes" indicates that The high voltage interlock circuit has a fault.

HVIC Return Current

mA

6.00 mA

This parameter displays the amount of return current in milli amps returning back to the battery energy control module (BECM) for high voltage interlock circuit detection as determined by the BECM.

HVIC Source Current

mA

6.25 mA

This parameter displays the amount of current sourced in milli amps for high voltage interlock current detection circuit as determined by the battery energy control module (BECM).

Hybrid Batt. Charge Hrs.

Ahrs

Varies

This parameter displays the total accumulated amount of amp hours charged or put in to the hybrid batteries as determined by the battery energy control module (BECM). This information will be reset to 0 when the BECM is reprogrammed or replaced.

Hybrid Batt. Charge Pwr Available

Watts

29100 to 30000

This parameter displays the charge power available in watts from the hybrid battery as determined by the battery energy control module (BECM) power limit calculation.

Hybrid Batt. Current Sensor

Volts

2.4-2.6 volts

This parameter displays the hybrid battery current sensor in volts as determined by the battery energy control module (BECM). This is a discreet input from the current sensor.

Hybrid Batt. Discharge Hrs.

Ahrs

Varies

This parameter displays the total accumulated amount of amp hours discharged from the hybrid batteries as determined by the battery energy control module (BECM). This information will be reset to 0 when the BECM is reprogrammed or replaced.

Hybrid Batt. Discharge Power Available

Watts

29100 to 30000

This parameter displays the discharge power available in watts from the hybrid battery as determined by the battery energy control module (BECM) power limit calculations.

Hybrid Batt. Inlet Air Temperature Sensor

Volts

3.2 volts

This parameter displays the hybrid battery air inlet temperature, in volts, as measured by the battery energy control module (BECM). This sensor is located in the inlet duct for the hybrid battery cooling fan.

Hybrid Batt. Max. Cell Temp.

°C (°F)

26°C (79°F)

This parameter displays the highest temperature value of all the hybrid battery modules temperature sensors as determined by the battery energy control module (BECM).

Hybrid Batt. Min. Cell Temp.

°C (°F)

24°C (75°F)

This parameter displays the lowest temperature value of all the hybrid battery module temperature sensors, as determined by the battery energy control module (BECM).

Hybrid Batt. Mod. 1 Temperature

°C (°F)

24°C (75°F)

This parameter displays the temperature of Hybrid Battery Module Temperature sensor 1 as measured by the battery energy control module (BECM), in °C (°F). The Hybrid Battery Module Temperature sensor 1 is located internal to the hybrid battery and located on hybrid battery number 1.

Hybrid Batt. Mod. 1 Temp. Sensor

Volts

3.2 volts

This parameter displays the Hybrid Battery Module temperature sensor 1, measured in volts, as determined by the battery energy control module (BECM). The Hybrid Battery Module Temperature sensor 1 is located internal to the hybrid battery and located on hybrid battery number 1.

Hybrid Batt. Mod. 2 Temperature

°C (°F)

26°C (79°F)

This parameter displays the temperature of Hybrid Battery Module Temperature sensor 2 as measured by the battery energy control module (BECM), in °C (°F). The Hybrid Battery Module Temperature sensor 2 is located internal to the hybrid battery and located on hybrid battery number 14.

Hybrid Batt. Mod. 2 Temp. Sensor

Volts

3.2 volts

This parameter displays the Hybrid Battery Module temperature sensor 2, measured in volts, as determined by the battery energy control module (BECM). The Hybrid Battery Module Temperature sensor 2 is located internal to the hybrid battery and located on hybrid battery number 14.

Hybrid Batt. Mod. 3 Temperature

°C (°F)

25°C (77°F)

This parameter displays the temperature of Hybrid Battery Module Temperature sensor 3 as measured by the battery energy control module (BECM), in °C (°F). The Hybrid Battery Module Temperature sensor 3 is located internal to the hybrid battery and located on hybrid battery number 27.

Hybrid Batt. Mod. 3 Temp. Sensor

Volts

3.2 volts

This parameter displays the Hybrid Battery Module temperature sensor 3, measured in volts, as determined by the battery energy control module (BECM). The Hybrid Battery Module Temperature sensor 3 is located internal to the hybrid battery and located on hybrid battery number 27.

Hybrid Batt. Mod. 4 Temperature

°C (°F)

26°C (79°F)

This parameter displays the temperature of Hybrid Battery Module Temperature sensor 4, measured by the battery energy control module (BECM), in °C (°F). The Hybrid Battery Module Temperature sensor 4 is located internal to the hybrid battery and located on hybrid battery number 40.

Hybrid Batt. Mod. 4 Temp. Sensor

Volts

3.2 volts

This parameter displays the Hybrid Battery Module temperature sensor 4, measured in volts, as determined by the battery energy control module (BECM). The Hybrid Battery Module Temperature sensor 4 is located internal to the hybrid battery and located on hybrid battery number 40.

Hybrid Batt. Outlet Air Temperature

°C (°F)

25°C (77°F)

This parameter displays the hybrid battery air outlet temperature value, in °C (°F), as measured by the battery energy control module (BECM). This sensor is clipped to the upper tension rod and is located above hybrid battery 3.

Hybrid Batt. Outlet Air Temperature Sensor

Volts

3.2 volts

This parameter displays the hybrid battery air outlet temperature value, in volts, of the hybrid battery, as measured by the battery energy control module (BECM). This sensor is clipped to the upper tension rod and is located above hybrid battery 3.

Hybrid Batt. Pack Fan Commanded

%

0

This parameter displays the duty cycle of the hybrid battery fan command in percent, as determined by the battery energy control module (BECM).

Hybrid Batt. Pack Resistance

Ohms

0.024 ohms

This parameter displays the impedance in ohms of the highest battery pair within the hybrid battery assembly, as measured by the battery energy control module (BECM).

Hybrid Battery 1 through 10

Volts

15.5 volts

This parameter displays the voltage value of hybrid battery voltage measurements #1-10 of the hybrid battery assembly, as measured by the battery energy control module (BECM). There are 40 hybrid batteries, measured at 20 locations. Each voltage parameter represents the sum of a pair of hybrid batteries.

Hybrid Battery 11

Volts

15.6 volts

This parameter displays the voltage value of the hybrid battery voltage measurement #11 of the hybrid battery assembly, as measured by the battery energy control module (BECM). This voltage parameter represents the sum of a pair of hybrid batteries. If the manual disconnect lever is removed, the parameter for #11 will display 0 volts.

Hybrid Battery 12 through 20

Volts

15.6 volts

This parameter displays the voltage value of the hybrid battery voltage measurements #12-20 of the hybrid battery assembly, as measured by the battery energy control module (BECM). There are 40 hybrid batteries, measured at 20 locations. Each voltage parameter represents the sum of a pair of hybrid batteries.

Hybrid Batt. Inlet Air Temperature

°C (°F)

23°C (73°F)

This parameter displays the air inlet temperature, in °C (°F), internal to the hybrid battery, as measured by the battery energy control module (BECM). This sensor is located in the inlet duct for the hybrid battery cooling fan.

Hybrid Battery Pack Calculated

Volts

331 volts

This parameter displays the total voltage of the hybrid battery assembly, as calculated by the battery energy control module (BECM) by summing up all 20 hybrid battery voltage measurement values.

Hybrid Battery Pack Fan

RPM

0=off

1375=low

This parameter displays the speed of the hybrid battery fan in RPM, as measured by the battery energy control module (BECM).

Hybrid Battery SOC

%

70

This parameter displays the calculated state of charge (SOC) of the hybrid battery as determined by the battery energy control module (BECM). This calculation incorporates many factors such as temperature, voltage and current.

Hybrid Battery Terminal

Volts

330 volts

This parameter displays the total hybrid battery voltage as measured by the battery energy control module (BECM) on the vehicle side of the High Voltage contactor relays. This measurement is only accurate when the both of the HV contactor relays are closed

Max. Hybrid Batt. Module Voltage

Volts

15.6 volts

This parameter displays the highest value in Volts of the 20 hybrid battery pair voltage measurement values, as determined by the battery energy control module (BECM).

Min. Hybrid Batt. Module Voltage

Volts

15.5 volts

This parameter displays the lowest value in volts of the 20 hybrid battery module voltage measurement values, as determined by the battery energy control module (BECM).

Precharge Ckt Overtemperature

Yes/No

No

This parameter displays the status of the 300V system. "Yes" indicates this is a reason the battery energy control module (BECM) can not close the high voltage contactors. This is not an actual temperature measurement. This is a calculation made by the BECM. "Yes" indicates that the BECM has calculated that the precharge circuit may be hot and has started the precharge wait time counter.

Precharge Inhibited

Yes/No

No

This parameter displays information about contactor open reasons as determined by the battery energy control module (BECM). "Yes" indicates that the BECM is disabling the precharge function.

Precharge Time Too long

Yes/No

No

This parameter displays the status of the 300V system. "Yes" indicates this is a reason the battery energy control module (BECM) can not close the high voltage contactors. The precharge time has taken too long. HV DC cables or circuits may be shorted causing higher current draws during the precharge process.

Precharge Time Too Short

Yes/No

No

This parameter displays the status of the 300V system. "Yes" indicates this is a reason the battery energy control module (BECM) can not close the high voltage contactors. The precharge time was to fast. High voltage DC cables/circuit may be open causing a fast precharge.

Precharge wait time

Seconds

0

This parameter displays the amount of time, in seconds, until the battery energy control module (BECM) will allow a 300V precharge sequence to occur. The BECM can disable precharge in order to protect the precharge resistor and circuit from overheating.

Service Disconnect

Yes/No

No

This parameter displays information about contactor open reasons as determined by the battery energy control module (BECM). "Yes" indicates that the HV manual disconnect lever has been removed.

Scan Tool Output Controls

Output Control

Description

Battery Pack Fan Speed

    • The "Battery Pack Fan Speed" represents the RPM of the hybrid battery vent fan. The "Hybrid Batt Pack Fan Commanded" value represents the percent duty cycle which determines the speed of the battery fan once the "Battery Pack Fan Speed" Special function is enabled. The hybrid battery pack fan speed output control on the scan tool can command the hybrid battery fan speed to 20 percent, 40 percent, or 60 percent.
    • The battery energy control module (BECM) receives a cooling fan request from serial data gateway module (SDGM). The BECM then controls the hybrid battery vent fan using a pulse width modulated circuit. Under certain operating temperatures or failure conditions the BECM will run the fan. The duty cycle is represented by a percentage of ON energized time. The higher the percent the faster the fan speed. Approximately 70 percent duty cycle represents an "ON" and "High" fan speed. Approximately 20 percent duty cycle represents an "ON" and "low" fan speed. Zero percent represents an "OFF" non-energized commanded state. The Hybrid Battery Pack Fan RPM value on scan tool should increase when Hybrid Battery Pack Fan Commanded percent duty cycle is increased.
    • When the output control is exited, the fan duty cycle is determined by the vehicle or the BECM.
    • The following control limits apply:
       - If the hybrid battery temperature is determined to be over 52°C (126°F) and the battery pack is in cooling mode, the hybrid battery fan may not be commanded OFF. If the fan is requested OFF, the message "Hybrid battery temp is out of range" appears on the scan tool display.
       - The hybrid battery pack fan may not be commanded ON if the RUN/Crank voltage is too low as detected by the BECM. If the RUN/Crank voltage is too low as detected, the message "RUN/Crank voltage is too low" appears on the scan tool display.
       - The hybrid battery pack fan may not be commanded On if the hybrid battery pack fan related DTCs are active. If hybrid battery pack fan related DTCs are active, the message "DTC present" appears on the scan tool display.

Negative Contactor

    • Hybrid battery "Negative Contactor" Special Function output control will allow the HV negative contactor relay to be closed by the BECM once the negative contactor relay output control is selected. The System will only allow the command of one contactor relay at a time. The high voltage manual disconnect must be removed.
    • The high voltage contactor relays are opened and closed by the BECM. The high voltage contactor relays are normally open. The control circuits for these contactor relays are high side drive. The BECM supplies 12 volts to the control circuit in order to close the contactor relay.
    • When the contactor relay is commanded CLOSED by using this special function, it will time out and open after approximately 15 seconds. When the output control is exited, the contactor relay is returned to the normally open position. You should be able to hear an audible click when the contactor relay open and closes.
    • The following control limits apply:
       - The high voltage manual disconnect lever must be removed.
       - The output control for HV contactor command will not work when the BECM detects that the HV contactor relay is not OPEN when commanded CLOSED. When the BECM detects that the HV contactor relay is not OPEN, "High voltage contactor state must be open" appears on the scan tool display. The output control for HV contactor command will not work when the BECM detects that the HV manual disconnect lever has not been removed. When the BECM detects that the HV manual disconnect lever has not been removed, "High voltage manual disconnect must be removed" appears on the scan tool display.

Positive Contactor

    • Hybrid battery "Positive Contactor" Special Function output control will allow the HV positive contactor relay to be closed by the BECM once the positive contactor relay output control is selected. The System will only allow the command of one contactor relay at a time. The high voltage manual disconnect must be removed.
    • The high voltage contactor relays are opened and closed by the BECM. The high voltage contactor relays are normally open. The control circuits for these contactor relays are high side drive. The BECM supplies 12 volts to the control circuit in order to close the contactor relay.
    • When the contactor relay is commanded CLOSED by using this special function, it will time out and open after approximately 15 seconds. When the output control is exited, the contactor relay is returned to the normally open position. You should be able to hear an audible click when the contactor relay open and closes.
    • The following control limits apply:
       - The high voltage manual disconnect lever must be removed.
       - The output control for HV contactor command will not work when the BECM detects that the HV contactor relay is not OPEN when commanded CLOSED. When the BECM detects that the HV contactor relay is not OPEN, "High voltage contactor state must be open" appears on the scan tool display. The output control for HV contactor command will not work when the BECM detects that the HV manual disconnect lever has not been removed. When the BECM detects that the HV manual disconnect lever has not been removed, "High voltage manual disconnect must be removed" appears on the scan tool display.

Precharge Contactor

    • Hybrid battery "Precharge Contactor" Special Function output control will allow the HV precharge contactor, also known as the current limit relay, to be closed by the BECM once the Precharge Contactor output control enable is selected. The System will only allow the command of one contactor relay at a time. The high voltage manual disconnect must be removed.
    • The high voltage contactor relays are opened and closed by the BECM. The high voltage contactor relays are normally open. The control circuits for these contactor relays are high side drive. The BECM supplies 12 volts to the control circuit in order to close the contactor relay.
    • When the precharge contactor, also known as the current limit relay, is commanded CLOSED by using this special function, it will time out and open after approximately 15 seconds. When the output control is exited, the contactor relay is returned to the normally open position. You should be able to hear an audible click when the contactor relay open and closes.
    • The following control limits apply:
       - The high voltage manual disconnect lever must be removed.
       - The output control for HV contactor command will not work when the BECM detects that the HV contactor relay is not OPEN when commanded CLOSED. When the BECM detects that the HV contactor relay is not OPEN, "High voltage contactor state must be open" appears on the scan tool display. The output control for HV contactor command will not work when the BECM detects that the HV manual disconnect lever has not been removed. When the BECM detects that the HV manual disconnect lever has not been removed, "High voltage manual disconnect must be removed" appears on the scan tool display.

300V Isolation Test

    • This output control test is designed to run the hybrid battery Isolation test with the contactors closed while connected to the EL-48458 pre-charge tester. This will test the HV DC cables for electrical Isolation and the HV DC Precharge sequence for operation. for installation and removal procedure of the pre-charge tester, refer to High Voltage System Diagnosis.
    • The BECM receives a PWM contactor command duty cycle input from the HCP. The duty cycle is represented by a percentage of ON time. A 30 percent duty cycle represents a close contactor command or energized state. A 70 percent duty cycle represents an open contactor command.
    • Before using this output control, the EL-48458 must be connected. Refer to High Voltage System Diagnosis for pre-charge tester installation and removal procedures. Install the EL-48458 pre-charge tester, Switch the ignition to the ON position, move the HV contactor relay switch on the EL-48458 pre-charge tester to the closed position, the BECM should then close the HV contactor relays. Verify that the high voltage circuit LED for Hi-voltage greater than 60 volts illuminates and stays illuminated. On the scan tool select the special function output control for the 300V Isolation test. The scan tool will then send a command to the BECM to run the isolation test and report the "isolation test resistance" results. When testing is complete, remove the EL-48458 , refer to High Voltage System Diagnosis.
    • The output control will not function unless the following conditions are met:
       - When the high voltage manual disconnect is removed as determined by the BECM.
       - GMLAN communications between the HPCM and the BECM
       - HVIC function disabled.