Body Control System Cadillac CTS I

Fastener Tightening Specifications

Fastener Tightening Specifications

Scheme 10

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Scheme 18

Dash Integration Module Terminal Identification (DIM) C1 Connector Part Information 12064871 10-Way F Metri-Pack 150 Series (BU) Pin Wire Color Circuit No. Function A-D - - Not Used E BK/WH 351 Ground F - - Not Used G RD/WH 1140 Battery Positive Voltage H YE 32 Instrument Panel Lamp Fuse Supply Voltage-1 J - - Not Used K YE 1491 Backlight Lamps Control

Dash Integration Module Terminal Identification (DIM) C2 Connector Part Information 12110088 24-Way F Micro-Pack 100 Series (GY) Pin Wire Color Circuit No. Function A1 - - Not Used A2 BN 4 Accessory Voltage A3 PK 3 Ignition 1 Voltage A4 L-GN/BK 592 DRL Relay Control A5 WH 111 Hazard Switch Signal A6 TN 28 Horn Relay Control A7 D-GN/WH 1317 Fog Lamp Relay Control A8 D-GN 1399 Cigar Relay Control (Early Production) A9-A11 - - Not Used A12 RD/WH 3340 Battery Positive Voltage B1-B3 - - Not Used B4 PK/WH 1970 Headlamp Low Beam Relay Control B5 WH 1080 Park Lamp Relay Control B6 TN 5052 Headlamp Washer Ground B7 TN/WH 1969 Headlamp High Beam Relay Control B8 D-GN 1483 Lighting Relay Coil Supply Voltage Control B9 TN 5026 Ignition Lock Cylinder Control Switch Signal (M82) B10-B11 - - Not Used B12 BK/WH 51 Ground

Dash Integration Module Terminal Identification (DIM) C3 Connector Part Information 12160778 24-Way F Micro-Pack 100 Series (BN) Pin Wire Color Circuit No. Function A1-A3 - - Not Used A4 D-GN 44 Instrument Panel Lamps Dimmer Switch Signal A5 - - Not Used A6 YE 5005 Instrument Panel Lamps Dimmer Switch Low Reference A7 L-BU/BK 1688 5-Volt Reference A8 TN/WH 99 Windshield Washer Fluid Level Signal A9 L-BU 1717 Hazard Request Signal A10 - - Not Used A11 PU 1807 Class 2 Serial Data A12 PU 1807 Class 2 serial Data B1 PK/BK 109 Hood Ajar Switch Signal (Export w/ UA2) B2 WH 103 Headlamp Switch Headlamps On Signal B3 BN/WH 301 Park Lamp Switch On Signal B4 WH 1538 Windshield Wiper Switch On Signal B5 PU 1783 Twilight Sentinel Delay Signal B6 OG 192 Front Fog Lamp Switch Signal B7 L-BU 187 Rear Fog Lamp Switch Signal (Export w/ T79) B8 BN 1356 Flash To Pass Switch Signal B9 PK/BK 1597 Courtesy Lamps Switch On Signal B10 L-GN 80 Key In Ignition Switch Signal B11-B12 - - Not Used

Rear Integration Module Terminal Identification (RIM) C1 Connector Part Information 12092632 16-Way F Micro-Pack 100 series (RD) Pin Wire Color Circuit No. Function A1 L-BU 5362 Inclination Sensor Signal (Export w/UA2) A2 BN/WH 1571 Traction Control Switch Signal A3 D-BU 2181 Passenger Heated Seat Control Module Status Signal (KA1) A4 PK 1339 Ignition 1 Voltage A5 D-BU/WH 149 Courtesy Lamp Supply Voltage A6 WH 111 Theft Deterrent Alarm Enable Signal (Export w/UA2) A7 L-BU/WH 181 Heated Seat Control Module Status Signal (KA1) A8 BK/WH 1051 Ground B1 PU 5059 Intrusion Sensor Alarm On Signal (Export w/ UA2/UA6) B2 GY 5054 Sport Mode Switch Signal (M82) B3 OG/BK 744 Rear Compartment Lid Ajar Switch Signal B4 - - Not Used B5 L-GN 5007 Backup Lamp Switch Signal (M35) 5053 Winter Mode Switch Signal (M82) B6-B7 - - Not Used B8 BK/WH 1051 Ground

Rear Integration Module Terminal Identification (RIM) C2 Connector Part Information 12160778 24-Way F Micro-Pack 100 Series (BN) Pin Wire Color Circuit No. Function A1 TN 755 RAP Relay Coil Control A2 - - Not Used A3 YE 1977 Rear Fog Lamp Relay Control (Export w/ T79) A4 - - Not Used A5 D-GN/WH 1135 A/T Shift Lock Control Solenoid Control (M82) A6 BN/WH 1429 Standing Lamp Relay Control (Export w/ T79) A7 - - Not Used A8 PK 5363 Inclination Sensor Low Reference (Export w/UA2) A9 - - Not Used A10 GY 157 Courtesy Lamp Control A11 RD/WH 540 Battery Positive Voltage A12 PU 1807 Class 2 Serial Data B1 WH 193 Rear Defog Relay Control B2 D-GN 646 Reverse Relay Control B3 BN 834 Vehicle Speed Signal (CF5) B4 L-BU 1344 Trunk Release Relay Control B5 D-BU 1393 Courtesy Lamp Relay Control B6 YE 5058 Intrusion Sensor Armed Signal (Export w/ UA2/UA6) B7 PK/BK 1503 Passenger Heated Seat High/Low Signal (KA1) B8 PK 1501 Driver Heated Seat High/Low Signal (KA1) B9 - - Not Used B10 GY 157 Courtesy Lamp Control B11 BK 1050 Ground B12 PU 1807 Class 2 Serial Data

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.

Scan Tool Data List

Dash Integration Module (DIM)

Rear Integration Module (RIM)

Diagnostic Trouble Code (DTC) List

Diagnostic Trouble Code (DTC) List

Circuit Description

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

Conditions for Running the DTC

The microprocessor 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.

Conditions for Setting the DTC

The microprocessor first writes information to a cell, or address, adds 0.25 to the value, calculates a check sum. If this check sum minus 0.25 is not equal to the cell value, the module sets the DTC.

Action Taken When the DTC Sets

The microprocessor 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

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.

DTC B1000

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 microprocessor and cannot be serviced separately.

The module microprocessor must be active/awake.

This DTC indicates the KAM in the module has been reset. It is a normal occurrence when battery positive voltage or ground is removed from the module, such as a battery disconnect.

The microprocessor 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.

1. Interruptions to either the battery positive voltage circuit or the module ground circuit will cause the DTC to set.
2. 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.
3. This DTC will never set as current during testing unless there is a non-recoverable memory failure.
4. If this DTC is retrieved as a current and history DTC, replace the module.

DTC B1004

As part of normal data processing, the module performs a data programming check on its writes to the electrically erasable read only memory (EEPROM). The EEPROM write error detection is handled inside the control module. No external circuits are involved.

The module runs the program to detect an EEPROM write error. The only requirements are battery positive voltage and ground. This program runs even if the battery positive voltage is out of the valid operating range.

The module writes information to a data block in the EEPROM. The module then reads the data and compares it to what was sent to the data block. If the data does not match after 3 consecutive attempts, the module sets the DTC.

The module writes to another area of the EEPROM, this becomes the new permanent area to store the data. The data location is allowed to change until all of the available EEPROM is used. If a B1004 DTC is also set, the module reverts to base operation values programmed for those blocks of data that have failed. The blocks of data that have not failed the checksum 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.

For modules other than the DIM

1. This DTC may be retrieved as a history DTC without affecting the operation of the module. If the DTC is retrieved 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.

DTC B1007

The electrically erasable read only memory (EEPROM) check sum error detection is handled inside the control module. No external circuits are involved.

The module runs the program to detect an EEPROM checksum error after each wake-up. The only requirements are battery positive voltage and ground. This program runs even if the voltage is out of the valid operating range.

The module retains an inverse copy of the digital value stored in certain blocks of memory in the EEPROM. The module then reads the information from those certain blocks and adds the stored inverse value to the current value. If they do not equal 0, the module sets the DTC.

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.

For modules other than the DIM

1. This DTC may be retrieved as a history DTC without affecting the operation of the module. If the DTC is retrieved 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.

DTC B1009

This test checks the validity of the module FLASH memory calibration values. Error detection is performed inside the control module. no external circuits are involved.

The module runs the program to detect a FLASH calibration error after each wake-up. The only requirements are battery positive voltage and ground.

The module retains a copy of the FLASH calibration checksum reference value in the FLASH memory. During wake-up the module shall compute the FLASH calibration value and compare it to the FLASH calibration checksum reference value. If the 2 values do not match the module sets this DTC.

The module may have limited functional operation depending on the severity of the FLASH calibration corruption. The module physical operation will allow for the module to be reprogrammed to correct the malfunction.

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 following are most likely cause for this DTC being set

1. Incorrect files downloaded to the module.
2. A module installed in the vehicle without the reprogramming procedure having been performed.

DTC B1013

This test checks the validity of the module FLASH memory application values. Error detection is performed inside the control module. No external circuits are involved.

The module runs the program to detect a FLASH application error after each wake-up. The only requirements are battery positive voltage and ground.

The module retains a copy of the FLASH application checksum reference value in the FLASH memory. During wake-up the module shall compute the FLASH application value and compare it to the FLASH application checksum reference value. If the 2 values do not match the module sets this DTC.

The module will enter boot mode when this DTC sets. In boot mode, only the program FLASH memory function will be available.

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 following are most likely cause for this DTC being set

1. Incorrect files downloaded to the module.
2. A module installed in the vehicle without the reprogramming procedure having been performed.

DTC B1014

Normal vehicle class 2 communication will not commence until the system power mode has been identified. The dash integration module (DIM) is the power mode master (PMM). The DIM communicates the system power mode to all the modules connected to the class 2 serial data circuit. The DIM monitors the state of the IGN 1 and Accessory voltage circuits in order to determine the present system power mode.

Anytime the DIM receives an input or message.

The DIM has detected the IGN 1 voltage circuit is low for greater than 1 minute when the Accessory voltage circuit is high and the engine run flag is true.

1. DTC B1372 is set in the DIM.
2. The malfunction indicator lamp (MIL) is illuminated.
3. The DIM along with other modules on the class 2 serial data circuit, will execute the power mode backup strategy.

Conditions for Clearing the MIL/DTC

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

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Device Power Moding

Test Description

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

1. 6: This step tests for a short to battery voltage on the active signal circuit.
2. 7: This step tests the inactive signal circuit for an open or a high resistance.
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.

DTC B1372

Normal vehicle class 2 communication will not commence until the system power mode has been identified. The dash integration module (DIM) is the power mode master (PMM). The DIM communicates the system power mode to all the modules connected to the class 2 serial data circuit. The DIM monitors the state of the IGN 1 and Accessory voltage circuits in order to determine the present system power mode.

Anytime the DIM receives an input or message.

The DIM has detected the Accessory voltage circuit is low for greater than 1 minute when the IGN 1 voltage circuit is high and the engine run flag is true.

1. DTC B1382 is set in the DIM.
2. The malfunction indicator lamp (MIL) is illuminated.
3. The DIM along with other modules on the class 2 serial data circuit, will execute the power mode backup strategy.

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

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Device Power Moding

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

1. 6: This step tests for a short to battery voltage on the active signal circuit.
2. 7: This step tests the inactive signal circuit for an open or a high resistance.
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.

DTC B1382

The DIM has an internal battery voltage sense input and a reference voltage input. 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 battery positive voltage 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. Setting of all loss of communication and low/high voltage DTCs are suspended.

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

DTC B1390

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the body control system. Refer to «Checking Aftermarket Accessories»(/cadillac/cts/i-2002-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__checking-aftermarket-accessories) in Wiring Systems.
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

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

Symptom List

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

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. 2: This step tests for proper circuit operation to permit communications.
2. 7: This step tests for battery voltage on the signal circuits that are not required.
3. 8: This step tests for no battery voltage on the required signal circuits.
4. 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.
5. 10: This step eliminates open circuits as the cause of the malfunction.

Power Mode Mismatch

Control Module References

Control Module References

Scheme 19

1. Remove the I/P closeout panel. Refer to «Closeout/Insulator Panel Replacement - Right»(/cadillac/cts/i-2002-2007/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges-and-console) .
2. Disconnect the closeout panel light electrical connector (1).
3. Remove the screws securing the dash integration module (DIM) to the I/P.
4. Disconnect the electrical connectors.

Installation Procedure

1. Connect the electrical connectors to the DIM.
2. Install the screws securing the DIM top the I/P. Tighten: Tighten the screws to 2 N.m (80 lb in).
3. Connect the closeout panel light electrical connector (1).
4. Install the I/P closeout panel. Refer to «Closeout/Insulator Panel Replacement - Right»(/cadillac/cts/i-2002-2007/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges-and-console) .
5. Program the module. Refer to «Body Control Module (BCM) Programming/RPO Configuration (RIM)»(/cadillac/cts/i-2002-2007/remont/communication-devices/#body-control-system) or «Body Control Module (BCM) Programming/RPO Configuration (DIM)»(/cadillac/cts/i-2002-2007/remont/communication-devices/#body-control-system) .

Scheme 20

1. Remove the rear shelf. Refer to «Shelf Carrier Replacement - Rear»(/cadillac/cts/i-2002-2007/remont/exteriorinterior-trim/#interior-trim) .
2. Remove the push pins securing the Rear Integration Module (RIM) (1) to the electrical carrier assembly.
3. Disconnect the electrical connectors.
4. Remove the RIM.

1. Install the RIM (1) to the electrical carrier.
2. Reinstall the push pin fasteners.
3. Reinstall the rear shelf. Refer to «Shelf Carrier Replacement - Rear»(/cadillac/cts/i-2002-2007/remont/exteriorinterior-trim/#interior-trim)
4. Program the module. Refer to «Body Control Module (BCM) Programming/RPO Configuration (RIM)»(/cadillac/cts/i-2002-2007/remont/communication-devices/#body-control-system) or «Body Control Module (BCM) Programming/RPO Configuration (DIM)»(/cadillac/cts/i-2002-2007/remont/communication-devices/#body-control-system) .

Procedure to Set Up a Rear Integration Module (RIM)

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 dash integration module (DIM) main menu, select Special Functions. Under the Special Functions menu, one of the choices is Set Options.
7. Under the Set Options menu, the user selects from the following as available. All listed options are for export only, and the selection should be NO for domestic vehicles. GM Trap Alert, to continue with the procedure follow the scan tool on screen instructions to deactivate GM Trap Alert. Intrusion Sensor Part A, to continue with the procedure follow the scan tool on screen instructions to select the intrusion sensor. Intrusion Sensor Part B, to continue with the procedure follow the scan tool on screen instructions to select the intrusion sensor. Inclination Sensor Part A, to continue with the procedure follow the scan tool on screen instructions to select the inclination sensor. Inclination Sensor Part B, to continue with the procedure follow the scan tool on screen instructions to select the inclination sensor. Alarm Siren Module Part A, to continue with the procedure follow the scan tool on screen instructions to select the alarm siren module. Alarm Siren Module Part B, to continue with the procedure follow the scan tool on screen instructions to select the alarm siren module. Exit, to go back to Special Functions menu.
8. Cycle the ignition key OFF for 5 seconds, then ON to complete the procedure.

1. Turn the ignition OFF for 10 seconds.
2. Connect the scan tool to the data link connector.
3. Turn the ignition ON with the engine OFF.
4. Use the scan tool in order to retrieve history DTCs from all modules.
5. Clear all history DTCs.

Procedure to Set Up a Dash Integration Module (DIM)

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: New VIN, to continue with the procedure. 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: Point of Sale, to continue with the procedure follow the scan tool on screen instructions to select the Point of Sale. Miscellaneous Options #2, should be turned ON. Variable Effort Steering, to continue with the procedure follow the scan tool on screen instructions to select Variable Effort Steering Right Hand Drive, to continue with the procedure follow the scan tool on screen instructions to select Right Hand Drive Personalization Option, to continue with the procedure follow the scan tool on screen instructions to select the RPO option configuration. Universal Theft Deterrent, to continue with the procedure follow the scan tool on screen instructions to select the RPO option configuration. Headlamp Type Option, to continue with the procedure follow the scan tool on screen instructions to select Headlamp Type Option Intrusion Sensor Part A, to continue with the procedure follow the scan tool on screen instructions to select the intrusion sensor. Intrusion Sensor Part B, to continue with the procedure follow the scan tool on screen instructions to select the intrusion sensor. Inclination Sensor Part A, to continue with the procedure follow the scan tool on screen instructions to select the inclination sensor. Inclination Sensor Part B, to continue with the procedure follow the scan tool on screen instructions to select the inclination sensor. Alarm Siren Module Part A, to continue with the procedure follow the scan tool on screen instructions to select the alarm siren module. Alarm Siren Module Part B, to continue with the procedure follow the scan tool on screen instructions to select the alarm siren module. Twilight Sentinel, to continue with the procedure follow the scan tool on screen instructions to select Twilight Sentinel Front Fog Lamp Type, to continue with the procedure follow the scan tool on screen instructions to select Front Foglamp Type DRL Option, to continue with the procedure follow the scan tool on screen instructions to select DRL Option Perimeter Lighting, to continue with the procedure follow the scan tool on screen instructions to select Perimeter Lighting TPM Option Enable, to continue with the procedure follow the scan tool on screen instructions to select TPM Option Enable. Exit, to go back to Special Functions menu.
17. Cycle the ignition key OFF for 5 seconds, then ON to complete the procedure.

1. Turn the ignition OFF for 10 seconds.
2. Connect the scan tool to the data link connector.
3. Turn the ignition ON with the engine OFF.
4. Use the scan tool in order to retrieve history DTCs from all modules.
5. Clear all history DTCs.

The body control system consists of the following 2 modules

1. The Dash Integration Module (DIM)
2. The Rear Integration Module (RIM)

Each of the 2 body control modules integrate a number of functional systems. Each module is connected to the class 2 serial data circuit, many of the control signals are implemented by class 2 messages.

Dash Integration Module (DIM)

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. cigar lighter relay control
2. class 2 communication requiring DIM interaction
3. exterior lighting control
4. headlamp washer control
5. hood ajar switch input w/export
6. horn relay control
7. interior lighting control
8. load management
9. low side temperature for HVAC compressor
10. park key lock output
11. power moding control over Class 2 serial data circuit
12. reverse lockout solenoid control
13. steering wheel controls input
14. storage of the clock settings and, sending a message out on the class 2 serial data circuit in response to requests from other modules
15. storage of vehicle options and configuration

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 2 signals from the ignition switch.

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

1. Accessory voltage
2. Run/Crank voltage

2-Wire Ignition Switch Table

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.

Electrical Load Management

The power management function is designed to monitor the vehicle electrical load and determine when the battery is potentially in a high discharge condition. This is accomplished by using a high accuracy battery voltage reading as an indicator of battery discharge rate. The following six levels of load management will execute in the load management control algorithm when there is a high discharge condition

1. The first action requests a vehicle idle speed increase to the engine control module (ECM) in order to raise alternator output.
2. The second action requests a greater vehicle idle speed increase to the ECM in order to raise alternator output.
3. The third action, begins to shed vehicle loads in an attempt to remedy the heavy discharge condition.
4. The fourth action requests another vehicle idle speed increase to the ECM in order to raise further the alternator output.
5. The fifth action, begins to shed further vehicle loads in an attempt to remedy the heavy discharge condition.
6. If the above five corrective actions fail, the sixth action of power management further sheds loads in a final attempt to remedy the high discharge condition.

Loads subject to reduction include the following

1. The A/C clutch
2. The heated mirrors
3. The heated seats
4. The rear defog
5. The HVAC blowers

The power mode master (PMM) calculates the battery temperature, voltage and charging rate at all times while the engine is running. The PMM calculates the battery temperature by factoring in

1. the current intake manifold air temperature compared to the last temperature recorded when the ignition switch was turned OFF
2. the current battery voltage compared to the last battery voltage recorded when the ignition switch was turned OFF
3. the length of time since the last battery temperature calculation

If the battery temperature is below set limits, the PMM institutes steps to control the load.

The PMM calculates the voltage of the battery by making constant measurements and using the measurements to calculate the true battery voltage. If the PMM detects a low voltage, the PMM institutes steps to control the load.

The PMM calculates the discharge rate, or draw, on the battery by making constant measurements and using the measurements to calculate the discharge rate in amp/hours. If the PMM detects a high current draw from the battery, the PMM institutes steps to control the load.

The PMM will either request an increase in the engine idle speed to the ECM or the PMM will cycle or turn off loads, called the load-shed function, in order to preserve the vehicle electrical system operation. The criteria used by the PMM to regulate this electrical load management are outlined below

Body Control System Description and Operation

Each load management function, either idle boost or load-shed, is discrete. No two functions are implemented at the same time.

During each load management function, the PMM checks the battery temperature, battery voltage and amp-hour calculations and determines if the PMM should implement a different power management function.

Idle Boost Functions

The PMM sends a serial data request to the ECM to increase the idle speed. The ECM then adjusts the idle speed by using a special program and idle speed ramp calculations in order to prevent driveability and safety concerns. The idle speed boost and cancel function will vary from vehicle to vehicle and from one moment to another on the same vehicle. This happens because the ECM responds to changes in the inputs from the sensors used to control the powertrain.

Load Shed Function

The PMM executes the load shed function, by controlling the relay coil of the following devices.

1. The A/C clutch
2. The heated mirrors
3. The heated seats
4. The rear defog
5. The HVAC blowers

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. Door ajar switch.
4. Headlamps are on.
5. Hood ajar switch.
6. Ignition is turned ON.
7. Key-in-ignition switch.
8. Parklamps are on.

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

1. Ignition switch is OFF.
2. No activity exists on the class 2 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.

Rear Integration Module (RIM)

The various RIM inputs and outputs are described in the corresponding functional areas as indicated on the RIM electrical schematics.

The RIM functions include the following

1. BTSI solenoid control
2. class 2 communication requiring RIM interaction
3. content theft deterrent
4. fuel door control
5. fuel level sensor input
6. heated seat control
7. intrusion sensor control
8. key in ignition chime control
9. performance shift control
10. position lamp control
11. park brake relay control
12. rear defog relay control
13. rear foglamp relay control
14. rear park assist chime control
15. retained accessory power (RAP) relay control
16. reverse lamp relay control
17. reverse switch input w/manual transmission
18. sunroof speed control
19. traction mode switch input
20. transmission shift inhibit
21. trunk ajar input
22. trunk entrapment sensor input
23. trunk release relay control
24. winter mode switch w/automatic transmission

See also:
• Testing for Intermittent Conditions and Poor Connections
• Circuit Testing
• Wiring Repairs
• Connector Repairs
• Ignition Switch Replacement
• Checking Aftermarket Accessories
• Amplifier Replacement
• Door Control Module Replacement
• Electronic Brake Control Module Replacement (CTS)
• Engine Control Module (ECM) Replacement
• Service Programming System (SPS)
• Diagnostic System Check - Engine Controls
• Engine Controls Schematics
• HVAC Control Module Replacement
• Inflatable Restraint Sensing and Diagnostic Module Replacement
• Diagnostic System Check - SIR
• Instrument Panel Cluster (IPC) Replacement
• Memory Seat Control Module Replacement
• Transmitter Programming
• Theft Deterrent Control Module Replacement
• Transmission Control Module (TCM) Replacement
• Diagnostic System Check - Automatic Transmission
• TV Antenna Module Replacement
• Communication Interface Module Replacement
• Fastener Notice
• Shelf Carrier Replacement - Rear
• DTC B1000
• Control Module References