Body Control System Buick LeSabre VIII

Fastener Tightening Specifications

Fastener Tightening Specifications

Body Control Module Schematics

See BODY COMPUTER .

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Begin the diagnosis of the body control system by performing the Diagnostic System Check for the system in which the customer concern is apparent. The Diagnostic System Check will direct you to the correct procedure for diagnosing the system and where the procedure is located.

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Scan Tool Data Definitions

8-Digit GM Part Number: The scan tool displays the 8-digit alphanumeric module part number.

A/C Clutch (Actual): The scan tool displays ON or OFF. ON is displayed when the PCM has energized the A/C clutch relay.

A/C Clutch (Desired): The scan tool displays ON or OFF. ON is displayed when the IPM is requesting A/C system operation and the DIM has determined that none of the system performance limits are exceeded.

A/C Orifice Relay: The scan tool displays Active or Inactive. Active is displayed when the orifice tube relay is energized by the DIM increasing the orifice diameter and lowering A/C high side pressure.

A/C Pressure: The scan tool displays 0-4000 kPa (0-580 psi). The output of the A/C pressure sensor provided by the PCM over the Class 2 communication link.

A/C Requested: The scan tool displays YES or NO. The message sent out on class 2 to the DIM when A/C is requested.

Accum Fault-Compressor: Defined period of time the compressor is active with out an exhaust cycle.

Accum Fault-Exhaust: Defined period of time that the exhaust is active with out a compressor cycle.

Air Inlet Dr Actual: The scan tool displays 0-255 counts (0-5 volts). The signal output from the feedback pot on the actuator.

Air Inlet Dr Commanded: The scan tool displays 0-255 counts (0-5 volts). The desired position of the actuator.

ALC Compressor Active: The scan tool displays YES if the ALC compressor is operating or NO if the is not operating.

ALC Exhaust Solenoid Active: The scan tool displays YES/NO. Display indicates the state of the ALC exhaust solenoid relay.

Ambient Light Sensor: The scan tool displays volts. Display indicates the ambient light sensor input signal, 0.09-4.75 volts is the normal operating range.

Battery Low-Compressor: The scan tool displays Active/Inactive. When the RIM detects battery voltage below 11 volts the RIM disables the ALC compressor.

Battery Reconnect: The scan tool displays ON/OFF. When the RIM senses a battery reconnect the scan tool will display ON.

Battery Save Active in Past: The scan tool displays YES/NO. Scan tool displays YES if the DIM has enter the battery save mode.

Battery Voltage: The scan tool displays 0-30 volts. The voltage measured between the module's battery positive voltage circuit and ground circuit.

Brake to Shift Relay: The scan tool displays ON/OFF. Display indicates the state of the stoplamp/auto trans shift lock control relay.

Calibration ID: The scan tool displays a 4-digit alphanumeric number. This number designates the modules calibrations.

Cigar Lighter Relay: The scan tool displays ON/OFF. Display indicates the commanded state of the cigar lighter relay.

Clutch Voltage: The scan tool displays LOW or NORMAL. LOW is displayed when the battery voltage is low, such that clutch slippage is possible.

Commanded Blower: The scan tool displays 0-100%.

Component Serial # 8-11: Digits 8-11 of the component serial number of the control module.

Component Serial # 12: Digit 12 of the component serial number of the control module.

Component Serial # 13-16: Digits 13-16 of the component serial number of the control module.

Component Serial # 17-18: Digits 17-18 of the component serial number of the control module.

Component Serial Number: The scan tool displays number. Display indicates the serial number of the module.

Control Head (Desired): The scan tool displays A/C ON or A/C OFF. A/C ON is displayed when the IPM is requesting A/C system operation.

Control Power: The scan tool displays ON/OFF. Display indicates the state of control power.

Coolant Temperature: The scan tool range is -39 to +140°C (-38 to +284°F). The PCM applies 5 volts to the ECT sensor circuit. The sensor is a thermistor that changes internal resistance as temperature changes. When the sensor is cold (internal resistance high), the PCM monitors a high signal voltage and interprets the voltage as a cold engine. As the sensor warms (internal resistance decreases), the voltage signal decreases and the PCM interprets the lower voltage as a warm engine.

CTD State: The scan tool displays Alarm/Armed/Arm Pending/Ignition/Standby, indicating the state of the Content Theft Deterrent System (CTD).

Daytime Running Lamp: The scan tool displays ON/OFF. Display indicates the commanded state of the daytime running lamp relay.

Driver Door Jamb Sw.: The scan tool displays ON/OFF. Display indicates the state of the drivers door jamb switch. ON indicates the door is open and OFF indicates the door is closed.

Driver/Pass. Heated Seat Sw.: The scan tool displays ON/OFF. This parameter indicate the mode of operation that has been selected.

Evaporator Temp: The scan tool displays -40 to +215°C (-40 to +420°F). The output of the A/C low side thermistor.

Evaporator Temp Status: The scan tool displays OK or Cold. Cold is displayed when evaporator temperature drops below 5°C (41°F).

Filter Position Value: The scan tool displays 0 to 255 counts (0 to 5 volts). As the vehicle operates, the suspension position sensor is monitored and the information is filtered, to the RIM so it can adjust the suspension.

Flash to Pass Switch: The scan tool displays ON/OFF. Display indicates the state of the flash to pass switch.

Front Fog Lamp Relay: The scan tool displays ON/OFF. Display indicates the commanded state of the front fog lamp relay.

Front Fog Lamp Switch: The scan tool displays ON/OFF. Display indicates the state of the front fog lamp switch.

Fuel Door Unlock Relay: The scan tool displays ON/OFF. Display indicates the state of the fuel door unlock relay.

Head Lamp Switch: The scan tool displays ON/OFF. Display indicates the state of the flash to pass switch signal. ON indicates the flash to pass headlamps are requested on.

Heated Seat Inhibit: The scan tool displays ON/OFF. When ON the RIM turns prevents activation of the heated seats.

High Beam Output: The scan tool displays ON/OFF. Display indicates the commanded state of the high beam relay.

Horn Output: The scan tool displays the commanded state of the horn relay. The scan tool displays ON when the Dash Integration Module (DIM) applies ground to the horn relay in order to activate the horns.

Htr./Def./A/C Dr. Actual: The scan tool displays 0-255 counts (0-5 volts). The signal output from the feedback pot on the actuator.

Htr./Def./A/C Dr. Commanded: The scan tool displays 0-255 counts (0-5 volts). The desired position of the actuator.

Pressure Status: The scan tool displays LOW, NORMAL OR HIGH. NORMAL must be displayed to allow A/C operation.

Ignition 3 Input: The scan tool displays ACTIVE/INACTIVE. The scan tool displays ACTIVE when the Ignition 3 input (run) circuit of the module receives a battery voltage signal from the ignition switch.

Ign. Accessory: The scan tool displays ACTIVE/INACTIVE. The scan tool displays ACTIVE when only the Accessory and unlock circuits of the Dash Integration Module (DIM) receives a battery voltage signal from the ignition switch.

Ignition Counter: The scan tool displays 0-50. The module counts each time the ignition switch is cycled

Ign. Crank/Run: The scan tool displays ACTIVE/INACTIVE. The scan tool displays ACTIVE when the Crank/Run, Run and Unlock circuits of the RIM receives a battery voltage signal from the ignition switch.

Ignition/Crank/Run: The scan tool displays ACTIVE/INACTIVE. The scan tool displays ACTIVE when the Crank/Run, Run and Unlock circuits of the DIM receives a battery voltage signal from the ignition switch.

Ign. Run: The scan tool displays ACTIVE/INACTIVE. The scan tool displays ACTIVE when the Run circuit of the DIM receives a battery voltage signal from the ignition switch.

Ignition Switch: The scan tool displays ACCY/CRANK/OFF/RAP/RAP-UNLOCK/RUN/UNLOCK. The scan tool displays ACCY when the accessory and unlock circuits of the DIM receives a battery voltage signal from the ignition switch. The scan tool displays CRANK when the Crank/Run, Run and Unlock circuits of the DIM receives a battery voltage signal from the ignition switch. The scan tool displays OFF when none of the power moding circuits of the DIM receive a battery voltage signal from the ignition switch. The scan tool displays RAP (Retained Accessory Power) when RAP is active and none of the power moding circuits of the DIM receive a battery voltage signal from the ignition switch. The scan tool displays RAP-Unlock when RAP is active and the lgn. Unlock circuit of the DIM receives a battery voltage signal from the ignition switch. The scan tool displays RUN when all of the power moding circuits of the DIM receive a battery voltage signal from the ignition switch. The scan tool displays UNLOCK when the Unlock circuit of the DIM receives a battery voltage signal from the ignition switch.

Ign Unlock: The scan tool displays ACTIVE/INACTIVE. The scan tool displays ACTIVE when only the Unlock circuit of the DIM receives a battery voltage signal from the ignition switch.

Inadvertent power Input: The scan tool displays ON/OFF. Display indicates the state of the inadvertent power.

Inadvertent Power Relay: The scan tool displays ON/OFF. Display indicates the commanded state of the inadvertent power relay.

Incandescent Dim #1: The scan tool displays ON/OFF. Display indicates the state of the incandescent lamp ground circuit.

Inside Air Temp-HVAC Sensors: The scan tool displays -40 to +60°C (-40 to +140°F). The output of the inside air temperature sensor.

Inside Air Temp-Open/Short Data: The scan tool displays 0-255 counts (0-5 volts). The status of the sensor signal circuit is monitored. Zero count indicates a short to ground, 255 counts indicates an open circuit.

Interior Dim Pot: The scan tool displays the amount of interior dimming requested in Counts.

Interior Lamp Switch: The scan tool displays OFF/AUTO/ON - Display indicates the position of the interior lamp switch - AUTO is the normal operating rang.

Julian Date of Build: The scan tool displays 3-digit numeric number. This is the day of the year that the module was built.

Key In Ignition: The scan tool displays YES/NO. The scan too displays YES when the key is in the ignition and the module receives a signal from the ignition switch.

Left A/C Duct Temp-HVAC Sensors: The scan tool displays -40 to +150°C (-40 to +300°F). The output of the LH A/C duct temperature sensor.

Left A/C Duct Temp-Open/Short Data: The scan tool displays 0-255 counts (0-5 volts). The status of the sensor signal circuit is monitored. Zero count indicates a short to ground, 255 counts indicates an open circuit. The scan tool displays 0-255 counts (0-5 volts). The status of the sensor signal circuit is monitored. Zero count indicates a short to ground, 255 counts indicates an open circuit.

Left Duct Temp Desired: The scan tool displays -40 to +150°C (-40 to +300°F). The output of the LH A/C duct temperature sensor.

Left Htr. Duct Temp-HVAC Sensors: The scan tool displays -40 to +150°C (-40 to +300°F). The output of the LH Htr. duct temperature sensor.

Left Htr. Duct Temp-Open/Short Data: The scan tool displays 0-255 counts (0-5 volts). The status of the sensor signal circuit is monitored. Zero count indicates a short to ground, 255 counts indicates an open circuit.

Left Program Number: The scan tool displays 0-25 counts. Display indicates the commanded temperature setting.

Left Rear Door Jamb Sw.: The scan tool displays ON/OFF. Display indicates the state of the left rear door jamb switch. ON indicates the door is open and OFF indicates the door is closed.

Left Solar: The scan tool displays 0-50 counts. The solar load output of the LH sunload sensor and ambient light sensor.

Left Solar Sensor: The scan tool displays 0-50 counts. The status of the sensor signal circuit is monitored. Zero count indicates a short to ground, 255 counts indicates an open circuit.

Left Temp Dr. Actual: The scan tool displays 0-255 counts (0-5 volts). The signal output from the feedback pot on the actuator.

Left Temp Dr. Commanded: The scan tool displays 0-255 counts (0-5 volts). The desired position of the actuator.

Leveling Sensor Feed: The scan tool displays volts, indicating the position of the ALC level sensor.

Load Shed Lvl. 1 Heated Seats: The scan tool displays ENABLED/DISABLED. When ENABLED the RIM cycles the heated seats at an 50% duty cycle.

Load Shed Lvl. 2 Heated Seats: The scan tool displays ENABLED/DISABLED. When ENABLED the RIM turns off the heated seats.

Load Shed Lvl. 1 R. Detog: The scan tool displays ENABLED/DISABLED. When ENABLED the RIM cycles the rear defog at an 80% duty cycle.

Load Shed Lvl. 2 R. Defog: The scan tool displays ENABLED/DISABLED. When ENABLED the RIM turns off the rear defog.

Load Reduction Active: The scan tool displays YES/NO. Display indicates the state of the IPM load reduction command.

Lights ON with Wipers: The scan tool displays ON/OFF. Display indicates the state of the wiper/washer system.

Low Beam Output: The scan tool displays ON/OFF. Display indicates the commanded state of the low beam relay.

Max Air Inlet Dr Pos: The scan tool displays 0-255 counts (0-5 volts). The minimum travel range when driven to the stop during Recalibrate All Motors command.

Max. Htr./Def./A/C Dr.: The scan tool displays 0-255 counts (0-5 volts). The minimum travel range when driven to the stop during Recalibrate All Motors command.

Max Left Temp Dr Pos: The scan tool displays 0-255 counts (0-5 volts). The maximum travel range when driven to the stop during Recalibrate All Motors command.

Max Right Temp Dr Position: The scan tool displays 0-255 counts (0-5 volts). The maximum travel range when driven to the stop during Recalibrate All Motors command.

Min Air Inlet Dr Pos: The scan tool displays 0-255 counts (0-5 volts). The minimum travel range when driven to the stop during Recalibrate All Motors command.

Min. Htr./Def.A/C Dr.: The scan tool displays 0-255 counts (0-5 volts). The minimum travel range when driven to the stop during Recalibrate All Motors command.

Min left Temp Dr Position: The scan tool displays 0-255 counts (0-5 volts). The minimum travel range when driven to the stop during Recalibrate All Motors command.

Min Right Temp Dr Position: The scan tool displays 0-255 counts (0-5 volts). The minimum travel range when driven to the stop during Recalibrate All Motors command.

Non-Overhead Lamps Relay: The scan tool displays ON/OFF. Display indicates the status of the overhead lamps relay.

Outside Air Temp-HVAC Sensors: The scan tool displays -40 to +60°C (-40 to +140°F). The output of the ambient air temperature sensor.

Outside Air Temp-Open/Short Data: The scan tool displays 0-255 counts (0-5 volts). The status of the sensor signal circuit is monitored. Zero count indicates a short to ground, 255 counts indicates an open circuit.

Overhead Lamps Output: The scan tool displays ON/OFF. Display indicates the commanded state of the overhead lamps.

Park Lamp: The scan tool displays ON/OFF. Display indicates the state of the park lamp switch.

Park Lamp Relay Output: The scan tool displays ON/OFF. Display indicates the commanded state of the park lamp relay.

Pass. Door Jamb Sw.: The scan tool displays ON/OFF. Display indicates the state of the right front door jamb switch. ON indicates the door is open and OFF indicates the door is closed.

Power Mode Change: The scan tool displays when the vehicles power source has changed to ON, IGN, or RAP and CTD is activated.

Pressure Status: The scan tool displays LOW, NORMAL OR HIGH. NORMAL must be displayed to allow A/C operation.

Progress Fault-Compressor: Defined period of time the that the compressor is active, and a change is not detected by the sensor.

Progress Fault-Exhaust: Defined period of time that the exhaust is active and no change is detected at the sensor.

PROM ID: The scan tool displays a 4-digit alphanumeric number. This is the modules internal PROM identification number.

RAP Output: The scan tool displays ON/OFF. Display indicates the status of the RAP function.

Rear Defog Relay: The scan tool displays ON/OFF. Display indicates the commanded state of the rear defog relay.

Rear Fog lamp Relay: The scan tool displays ON/OFF. Display indicates the commanded state of the rear fog lamp relay.

Rear Fog lamp Switch: The scan tool displays ON/OFF. Display indicates the state of the rear fog lamp switch.

Reverse Lamp Relay: The scan tool displays ON/OFF. Display indicates the commanded state of the reverse lamp relay.

Reverse Lockout Drive: The scan tool displays ON/OFF. Display indicates the status of the reverse lockout function.

Right AC Duct Temp-HVAC Sensors: The scan tool displays -40 to +150°C (-40 to +300°F). The output of the RH A/C duct temperature sensor.

Right AC Duct Temp-Open/Short Data: The scan tool displays 0-255 counts (0-5 volts). The status of the sensor signal circuit is monitored. Zero count indicates a short to ground, 255 counts indicates an open circuit.

Right Duct Temp Desired: The scan tool displays -18 to +120°C (0 to 250°F). The target RH A/C duct temperature that the HVAC system is trying to achieve.

Right Htr. Duct Temp-HVAC Sensors: The scan tool displays -40 to +150°C (-40 to +300°F). The output of the RH Htr. duct temperature sensor.

Right Htr. Duct Temp-Open/Short Data: The scan tool displays 0-255 counts (0-5 volts). The status of the sensor signal circuit is monitored. Zero count indicates a short to ground, 255 counts indicates an open circuit.

Right Program Number: The scan tool displays 0-255 counts. Display indicates the commanded temperature setting.

Right Solar: The scan tool displays 0-50 counts. The solar load output of the RH sunload sensor and ambient light sensor.

Right Solar Sensor: The scan tool displays 0-50 counts. The status of the sensor signal circuit is monitored. Zero count indicates a short to ground, 255 counts indicates an open circuit.

Right Temp Dr Actual: The scan tool displays 0-255 counts (0-5 volts). The signal output from the feedback pot on the actuator.

Right Temp. Dr Commanded: The scan tool displays 0-255 counts (0-5 volts). The desired position of the actuator.

Rt Rear Door Jamb Sw.: The scan tool displays ON/OFF. Display indicates the state of the right rear door jamb switch. ON indicates the door is open and OFF indicates the door is closed.

Run/Crank: The scan tool displays ACTIVE/INACTIVE. The scan tool displays ACTIVE when the Crank/Run circuit of the RIM receives a battery voltage signal from the ignition switch.

Selected Air Mode: The scan tool displays AUTO, Upper, Defog, Bi-Level, Heater or Defrost. The current operating mode of the HVAC system.

Steering Wheel Controls: The scan tool displays 0-999 counts. The signal in counts as received from the steering wheel controls.

Suspension Position Sensor: The scan tool displays 0-5 volts. Display indicates the position of the suspension position sensor.

System Program Number: The scan tool displays 0-255 counts. Display indicates the commanded temperature setting.

TCS Switch: Display OFF or ON. Indicates the status of the traction control switch.

Temperature Status: The scan tool displays HOT or OK. HOT is displayed when engine coolant temperature rises above 121°C (250°F). OK must be displayed to allow A/C operation.

Trim Value: A value programed in the RIM

Trunk Ajar Switch: The scan tool displays ON/OFF. Display indicates the state of the trunk ajar switch. ON indicates the trunk is open and OFF indicates the trunk is closed.

Trunk Release Output: The scan tool displays ON/OFF. Display indicates the state of the trunk release switch.

Twilight Delay Pot: The scan tool displays 0-255 counts. Display indicates the position of the twilight delay potentiometer

Vehicle Speed: The scan tool displays km/h and mph. The vehicle speed sensor signal is converted into km/h and mph for display.

Year Module Built: This displays the 4-digit year of build.

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Circuit Description

The internal fault detection is handled inside the control module. No external circuits are involved.

Conditions for Running the DTC

The module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

Action Taken When the DTC Sets

The module refuses all additional inputs.

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.

Diagnostic Aids

Note. For the Instrument Panel Module (IPM) go to DTC B1000: ECU MALFUNCTION .

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1. This DTC may be stored as a history DTC with out affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.
2. If this DTC is retrieved as both a current and history DTC, replace the module.

This DTC is generated when the Instrument Panel Integration Module (IPM) is not calibrated to the vehicle.

The DTC is run when the ignition is cycled from OFF to ON.

Conditions for Setting the DTC

The DTC is generated when the IPM is not calibrated to the vehicle.

The vehicle will continue to operate with the existing calibration.

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.

The most likely occurrence of this DTC being set are due to incorrect calibration files downloaded to the IPM, or an HVAC control module installed in the vehicle without the recalibration procedure having been performed.

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The module contains a data storage area which can save pertinent data when the ignition is turned OFF. The Keep Alive Memory (KAM) data is lost if battery power is removed from the module. The KAM area is an integral part of the module and cannot be serviced separately.

The module must be active/awake.

DTC B1004 indicates that the keep alive, or long term, memory in the module has been reset. This is a normal occurrence whenever power or ground is removed from the module, such as when the battery is disconnected and reconnected.

The module reverts back to the base programmed critical operating data until new data is learned and stored in KAM.

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.

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1. This DTC may be stored as a history DTC with out affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.
2. This DTC will never set as current during testing unless there is a non-recoverable memory failure.
3. Intermittent interruptions to either the battery positive voltage circuit or the module ground circuit will cause the DTC to set. Refer to «TESTING FOR INTERMITTENT AND POOR CONNECTIONS»(/buick/lesabre/viii-2000-2005/remont/body-electrical/#testing-wiring-systems-for-intermittent-poor-connections) .
4. If this DTC is retrieved as both a current and history DTC, replace the module.

The EEPROM write error detection is handled inside the control module. No external circuits are involved.

The module runs the program in order to detect a write error whenever the module writes to the EEPROM. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

The module first writes information to a cell, or address, in the EEPROM. The module then reads the information and compares the information to what was sent to the address. If they do not match after 3 consecutive attempts, the module sets this DTC.

The module tried to write to the memory location 3 times, if the write is not accomplished, the DTC is set.

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.

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1. This DTC may be stored as a history DTC with out affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.
2. If this DTC is retrieved as both a current and history DTC, replace the module.

The EEPROM check sum error detection is handled inside the control module. No external circuits are involved.

The module runs the program in order to detect a check sum error after each power up. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

The module reverts to base operation values programed for those blocks of data that have failed the check sum test. The blocks of data that have not failed the check sum test are not affected.

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.

Note. The DIM must be replaced if this DTC is retrieved from the DIM as either current or history. If this DTC is retrieved from any other module as a history DTC only do not replace the module.

Note. The IPM must be recalibrated with the latest calibration before replacement. Refer to Body Control Module (BCM) Programming/RPO Configuration (DIM) , Body Control Module (BCM) Programming/RPO Configuration (IPM) or Body Control Module (BCM) Programming/RPO Configuration (RIM) .

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1. This DTC may be stored as a history DTC with out affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.
2. If this DTC is retrieved as both a current and history DTC, replace the module.

The calibration ROM check sum error detection is handled inside the control module. No external circuits are involved.

The module runs the program in order to detect a ROM check sum error after each power up. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

The module reverts to base operation values programed for those blocks of data that have failed the ROM check sum test. The blocks of data that have not failed the check sum test are not affected.

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.

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1. This DTC may be stored as a history DTC with out affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.
2. If this DTC is retrieved as a current DTC, replace the module.

The DIM has an internal battery voltage sensor and a reference voltage. The DIM compares these 2 voltages via the 2 battery positive voltage circuits every 300 milliseconds.

This DTC will run only if the DIM has power and ground. This DTC will execute regardless of the source voltage.

This code shall be set after 10 consecutive readings that the 2 battery positive voltages differ by 1 volt or greater.

All writes to the EEPROM will be suspended. All loss of communication and low/high voltage DTC codes are suspended.

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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.

Normal vehicle Class 2 communications will not commence until the system power mode has been identified. Four discrete wires from the ignition switch contacts are monitored by the Dash Integration Module (DIM) in order to determine the present power mode. The DIM communicates the system power mode to all Class 2 modules on the Class 2 serial data line.

The DIM must be powered.

One of the 4 monitored ignition switch circuits is open or shorted.

The DIM implements default actions for each ignition switch position when faults are detected.

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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.

Test Description

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

1. 7. This step tests for a short to battery voltage on the active signal circuit.
2. 8. This step tests the inactive signal circuit for an open or a high resistance.
3. 9. If any ignition switch parameters that should be inactive in the present ignition switch position are active, 2 ignition switch signal circuits may be shorted together.

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The Electrically Erasable Programmable Read Only Memory (EEPROM) write error detection is handled inside the control module. No external circuits are involved. The module calibrations are stored in EEPROM. When you turn ON the ignition, the module performs internal tests on the EEPROM. The test may determine the integrity of the non-volatile memory. The module compares the previously stored checksum with a checksum calculated when the ignition turns ON. If the 2 checksums do not match, the module will indicate that a calibration malfunction is current.

1. The stored checksum does not match the calculated checksum.
2. The module detects an internal memory malfunction.
3. The condition occurs when the ignition is first turned ON.

The module runs the program to detect a write error whenever it writes to the EEPROM. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

The module finds another area to write the information to. This new area becomes the permanent area for storage of this information.

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.

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1. This DTC may be stored as a history DTC with out affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.
2. If this DTC is retrieved as both a current and history DTC, replace the module.

Note. Review the system operation in order to familiarize yourself with the system functions. Refer to Body Control System Description and Operation .

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the body control system.
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 AND POOR CONNECTIONS .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom. See Power Mode Mismatch .

Normal vehicle class 2 communications and module operations will not begin until the system power mode has been identified. Discrete wires from the ignition switch contacts are monitored by the Power Mode Master (PMM) module in order to determine the correct power mode. The PMM communicates the system power mode to all class 2 modules on the class 2 serial data line. Refer to Body Control System Description and Operation to identify which module is the PMM and the applicable power mode look up table.

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

1. 6. This step tests for battery voltage on the signal circuits that are not required.
2. 7. This step tests for no battery voltage on the required signal circuits.
3. 8. If any ignition switch parameters that should be inactive in the present ignition switch position are active, 2 ignition switch signal circuits may be shorted together.
4. 9. This step eliminates open circuits as the cause of the malfunction.

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1. Before replacement, record the personalization settings to transfer to the new module (if they are available). Refer to «Body Control Module (BCM) Programming/RPO Configuration (DIM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) , «Body Control Module (BCM) Programming/RPO Configuration (IPM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) or «Body Control Module (BCM) Programming/RPO Configuration (RIM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) .
2. Remove the right sound insulator.
3. Remove the Dash Integration Module (DIM) from the bracket by releasing the tab behind the module and pulling downward.
4. Disconnect the electrical connectors (1).

Scheme 39

1. Connect the electrical connectors (1).
2. Install the DIM into the bracket.
3. Install the right sound insulator.
4. Reprogram the DIM. Refer to «Body Control Module (BCM) Programming/RPO Configuration (DIM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) , «Body Control Module (BCM) Programming/RPO Configuration (IPM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) or «Body Control Module (BCM) Programming/RPO Configuration (RIM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) .

Scheme 40

1. Remove the left sound insulator.
2. Remove the fastener (2) from the instrument panel module (IPM).
3. Rotate the IPM up and off of the IP retainer.
4. Disconnect the electrical connectors from the IPM (1).
5. Remove the IPM (1) from the vehicle.

Scheme 41

1. Install the instrument panel module (IPM) (1) to the vehicle.
2. Connect the electrical connectors to the IPM (1).
3. Install the IPM (1) to the IP retainer by inserting the top tab of the module into the slot on the IP retainer and rotating down.
4. Install the fastener. Tighten: Tighten fastener to 2 N.m (18 in. Lb.)
5. Install the left closeout/insulator panel.

Scheme 42

1. Before replacing the RIM, record the personalization settings to transfer to the new module (if they are available). Refer to «Body Control Module (BCM) Programming/RPO Configuration (DIM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) , «Body Control Module (BCM) Programming/RPO Configuration (IPM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) or «Body Control Module (BCM) Programming/RPO Configuration (RIM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) .
2. Remove the rear seat cushion.
3. Remove the rear seat back.
4. Move the rear seat back insulator aside.
5. Remove the push pin retainers (1).
6. Disconnect the Rear Integration Module (RIM) electrical connectors (3).
7. Remove the RIM (2).

Scheme 43

1. Install the RIM (2).
2. Connect the RIM electrical connectors (3).
3. Install the RIM (2) with the push pin retainers (1).
4. Reposition the rear seat back insulator.
5. Install the rear seat back.
6. Install the rear seat cushion.
7. Reprogram, the RIM. Refer to «Body Control Module (BCM) Programming/RPO Configuration (DIM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) , «Body Control Module (BCM) Programming/RPO Configuration (IPM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) or «Body Control Module (BCM) Programming/RPO Configuration (RIM)»(/buick/lesabre/viii-2000-2005/remont/communication-devices/#body-control-system) .

Procedure to Set Up a Dash Integration Module (DIM)

Note. The Air Bag Indicator light may remain ON after the DIM Module is replaced and during the programming procedure for the DIM until after the procedure is completed and the ignition key is cycled OFF and ON.

1. Ensure the scan tool has been updated with the latest software version.
2. Ensure the battery is fully charged.
3. Ensure all modules on the serial data line are connected.
4. Connect a scan tool to the Data Link Connector (DLC).
5. Turn ON the ignition, with the engine OFF.
6. Under the DIM Main Menu, select SPECIAL FUNCTIONS. Under the SPECIAL FUNCTIONS menu, one of the choices is NEW VIN.
7. The user selects one of the following: 7.1. NEW VIN, to continue with the procedure. 7.2. EXIT, to go back to SPECIAL FUNCTIONS menu.
8. After the user chooses NEW VIN, follow the scan tool on screen instructions to edit VIN: Press SAVE to save VIN information. Press DONE to go back to SPECIAL FUNCTIONS menu.
9. Under the SPECIAL FUNCTIONS menu, one of the choices is SETUP SDM SERIAL NUMBER IN DIM.
10. The user selects one of the following: SETUP SDM SERIAL NUMBER IN DIM, to continue with the procedure. EXIT, to go back to SPECIAL FUNCTIONS menu.
11. After the user chooses SETUP SDM SERIAL NUMBER IN DIM, the scan tool displays a screen as follows: DO YOU WANT TO SET UP A DASH INTEGRATION MODULE? Press YES to set up module. Press NO to EXIT.
12. Choose YES or NO. If the user selects NO, the scan tool display returns to the DIM SPECIAL FUNCTION MENU. If the user selects YES, the scan tool displays INITIALIZING NEW MODULE.
13. Once complete, the scan tool displays MODULE INITIALIZED.
14. To complete the procedure, select: EXIT. Go To SPECIAL FUNCTIONS MENU.
15. The user selects one of the following: SET OPTIONS, to continue with the procedure. EXIT, to go back to Special Functions menu.
16. Under the SET OPTIONS menu, the user selects from the following as available: AUTOMATIC/MANUAL HVAC OPTIONS, to continue with the procedure follow the scan tool on screen instructions to Select the RPO option configuration. Type OPTION, to continue with the procedure follow the scan tool on screen instructions to Select the HEADLAMP TYPE OPTION CONFIGURATION. LH DRVR. PERSONALIZATION, to continue with the procedure follow the scan tool on screen instructions to Select the LH DRVR PERSONALIZATION OPTION CONFIGURATION. MAGNA STEER OPTION, to continue with the procedure follow the scan tool on screen instructions to Select the RPO OPTION CONFIGURATION. MISCELLANEOUS OPTIONS #1, to continue with the procedure follow the scan tool on screen instructions to Select the RPO OPTION CONFIGURATION. MISCELLANEOUS OPTIONS #2, should be turned ON. PERSONALIZATION OPTION, to continue with the procedure follow the scan tool on screen instructions to Select the RPO OPTION CONFIGURATION. POINT OF SALE, to continue with the procedure follow the scan tool on screen instructions to Select the POINT OF SALE. RH DRVR. PERSONALIZATION, to continue with the procedure follow the scan tool on screen instructions to Select the RH DRVR PERSONALIZATION OPTION CONFIGURATION. RIGHT HAND DRIVE, to continue with the procedure follow the scan tool on screen instructions to Select RIGHT HAND DRIVE OPTION CONFIGURATION. UNIVERSAL THEFT DETERRENT, to continue with the procedure follow the scan tool on screen instructions to Select the RPO OPTION CONFIGURATION. EXIT, to go back to SPECIAL FUNCTIONS menu.
17. Cycle the ignition key OFF and ON. NOTE: After programming, perform the following to avoid future misdiagnosis: Turn the ignition OFF for 10 seconds. Connect the scan tool to the Data Link Connector. Turn the ignition ON with the engine OFF. Use the scan tool in order to retrieve HISTORY DTCs from all modules. Clear all HISTORY DTCs.

Procedure to Calibrate an Instrument Panel Integration Module (IPM)

Ensure the scan tool has been updated with the latest software version.

The following steps should be followed to perform the recalibration update.

1. Ensure the scan tool has been updated with the latest software version.
2. Connect a scan tool to the Data Link Connector (DLC).
3. The ignition should be ON, but the engine should not be operating.
4. Select INSTRUMENT PANEL MODULE.
5. Select SPECIAL FUNCTIONS.
6. Select MISCELLANEOUS TEST.
7. Select IPM RECALIBRATION.

The scan tool will recalibrate the IPM with the latest version. To verify the proper version has been installed follow these steps

1. Select DATA DISPLAY.
2. Select MODULE INFORMATION.
3. View the CALIBRATION ID NUMBER. The calibration number must match the version loaded on the scan tool.

Note. After programming, perform the following to avoid future misdiagnosis: Turn the ignition OFF for 10 seconds. Connect the scan tool to the Data Link Connector. Turn the ignition ON with the engine OFF. Use the scan tool in order to retrieve HISTORY DTCs from all modules. Clear all HISTORY DTCs.

Procedure to Calibrate a Rear Integration Module (RIM)

After replacement of the RIM, perform the following procedure to recalibrate the automatic level control.

1. Ensure the scan tool has been updated with the latest software version.
2. Connect a scan tool to the Data Link Connector (DLC).
3. Turn ON the ignition, with the engine OFF.
4. Under the CHASSIS MAIN MENU, select REAR INTEGRATION MODULE.
5. Under the REAR INTEGRATION MODULE MAIN MENU, select RECALIBRATION.
6. Follow the scan tool on screen instructions to recalibrate the automatic level control.
7. Perform the vehicle personalization settings. Refer to PERSONALIZATION DESCRIPTION AND OPERATION in PERSONALIZATION .

Note. After programming, perform the following to avoid future misdiagnosis: Turn the ignition OFF for 10 seconds. Connect the scan tool to the Data Link Connector. Turn the ignition ON with the engine OFF. Use the scan tool in order to retrieve HISTORY DTCs from all modules. Clear all HISTORY DTCs.

The body control system consists of the following 3 modules

1. The Dash Integration Module (DIM)
2. The Instrument Panel Integration Module (IPM)
3. The Rear Integration Module (RIM)

Each of the 3 body control modules integrate a number of functional systems under the control of a single module. Each of the modules are connected to the Class 2 serial data line; many control signals are implemented by Class 2 messages.

Dash Integration Module (DIM)

The DIM is wired to the class 2 serial data line. The various DIM input and output circuits are described in the corresponding functional areas as indicated on the DIM electrical schematics.

The DIM functions include the following

1. Control of headlights and exterior lamps
2. Horn relay control
3. Interior lamps incandescent dimming
4. Lamps ON signal with wiper/washer
5. Power moding control over Class 2 serial data line
6. Steering wheel controls
7. Storage of the clock settings and, sending a message out on the class 2 serial data circuit in response to requests from other modules

Serial Data Power Mode

On vehicles that have several control modules connected by serial data circuits, one module is the Power Mode Master (PMM). On this vehicle the PMM is the DIM. The PMM receives 4 signals from the ignition switch.

To determine the correct power mode the PMM uses the following circuits

1. Accessory voltage
2. Ignition 1 voltage
3. Ignition 3 voltage
4. OFF/Run/Crank voltage

Scheme 44

Fail-safe Operation

Since the operation of the vehicle systems depends on the power mode, there is a fail-safe plan in place should the PMM fail to send a power mode message. The fail-safe plan covers those modules using exclusively serial data control of power mode as well as those modules with discrete ignition signal inputs.

Serial Data Messages

The modules that depend exclusively on serial data messages for power modes stay in the state dictated by the last valid PMM message until they can check for the engine run flag status on the serial data circuits. If the PMM fails, the modules monitor the serial data circuit for the engine run flag serial data. If the engine run flag serial data is True, indicating that the engine is running, the modules fail-safe to RUN. In this state the modules and their subsystems can support all operator requirements. If the engine run flag serial data is False, indicating that the engine is not running, the modules fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

Discrete Ignition Signals

Those modules that have discrete ignition signal inputs also remain in the state dictated by the last valid PMM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, battery positive voltage, the modules will fail-safe to the RUN power mode. If the discrete ignition input is not active, open or 0 voltage, the modules will fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

DIM Wake-up/Sleep States

The DIM is able to control or perform all of the DIM functions in the wake-up state. The DIM enters the sleep state when active control or monitoring of system functions has stopped, and the DIM has become idle again. The DIM must detect certain wake-up inputs before entering the wake-up state. The DIM monitors for these inputs during the sleep state, where the DIM is able to detect switch transitions that cause the DIM to wake-up when activated or deactivated. Multiple switch inputs are needed in order to sense both the insertion of the ignition key and the power mode requested. This would allow the DIM to enter a sleep state when the key is IN or OUT of the ignition.

The DIM will enter a wake-up state if any of the following wake-up inputs are detected

1. Activity on the serial data line.
2. Detection of a battery disconnect and reconnect condition.
3. Headlamps are ON.
4. Ignition is turned ON.
5. Key-in-ignition switch.
6. Park Lamps are ON.

The DIM will enter a sleep state when all of the following conditions exist

1. The ignition switch is OFF.
2. No activity exists on the serial data line.
3. No outputs are commanded.
4. No delay timers are actively counting.
5. No wake-up inputs are present.

If all these conditions are met the DIM will enter a low power or sleep condition. This condition indicates that the DIM, which is the PMM of the vehicle, has sent an OFF-ASLEEP message to the other systems on the serial data line.

Instrument Panel Integration Module (IPM)

The IPM is wired to the class 2 serial data line. The various IPM input and output circuits are described in the corresponding functional areas as indicated on the IPM electrical schematics.

The IPM functions include the following

1. V ambient light sensor input and twilight delay input for headlights control.
2. The front HVAC air delivery and temperature controls.
3. The IP dimmer switch input.
4. The ignition switch headlight control.
5. The interior lamps switch input.
6. The key-in-ignition switch input from the ignition switch.
7. The rear compartment lid release switch input.
8. The traction control switch input.

Rear Integration Module (RIM)

The RIM is wired to the class 2 serial data line. The various RIM input and output circuits are described in the corresponding functional areas as indicated on the RIM electrical schematics.

The RIM functions include the following

1. The ajar switch and tamper switch inputs from the rear compartment lid
2. The automatic level control
3. The cigar lighter relay control
4. The fuel door lock and release control
5. The heated seat controls
6. The park brake relay control
7. The rear compartment lid release controls
8. The rear defogger relay control
9. The Retained Accessory Power (RAP) relay control
10. The reverse lamp relay control
11. The various controls for the interior lamps

See also:
• DTC B1000: ECU MALFUNCTION
• TESTING FOR INTERMITTENT AND POOR CONNECTIONS
• Body Control Module (BCM) Programming/RPO Configuration (DIM)