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Body Control Modules Chevrolet Impala VIII

Communication Devices 45 illustrations ~29489 words

DESCRIPTION & OPERATION

WARNINGVehicles are equipped with Supplemental Inflatable Restraint (SIR) system. Before attempting ANY repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may be present until computer systems have completed a relearn cycle. See POWERTRAIN CONTROL MODULE under PROGRAMMING before disconnecting battery.

BODY CONTROL MODULE FUNCTIONS

Body Control Module (BCM) performs multiple body control functions. BCM can control devices directly connected to its outputs based on input information obtained from two sources

  1. Sensors and switches that are directly connected to BCM.
  2. Information received from other vehicle systems connected to class 2 serial data link.

BCM evaluates this information and controls certain body control systems by commanding outputs on or off.

BCM is also capable of controlling other vehicle systems that are not directly wired to BCM. BCM does this by sending specific messages on class 2 serial data link. Vehicle system capable of performing a required function will respond to BCM message.

BCM controls following functions

  1. Audible warnings.
  2. Interior lighting.
  3. Automatic door locks.
  4. Automatic headlight control.
  5. Keyless entry (if equipped).
  6. Passlock theft deterrent.
  7. Content theft deterrent.
  8. Retained Accessory Power (RAP).

SERIAL DATA POWER MODE

On vehicles that have several control modules connected by serial data circuits, one module is Power Mode Master (PMM). On this vehicle PMM is Body Control Module (BCM). BCM receives 3 signals/circuits from ignition switch: ACC/RUN/CRANK (ignition 0), RUN/CRANK (ignition 1) and ACC/RUN (accessory).

To determine correct power mode, BCM uses following information

  1. State of these signals/circuits, either switch closed (battery voltage = 1) or switch open (open = 0).
  2. Sequence of switch closures received by BCM.
  3. Status of engine run flag.

FAIL-SAFE OPERATION

Since operation of vehicle systems depends on power mode, there is a fail-safe plan in place should BCM fail to send a power mode message. 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

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

Discrete Ignition Signals

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

DATA LINK CONNECTOR

The Data Link Connector (DLC) is a standardized 16-pin connector located below instrument panel, right of steering column. Both connector design and location are dictated by industry wide agreement to follow SAE J1962 standards.

All DLCs are required to provide a power supply, hot at all times, to Pin 16. This circuit is used to power scan tool. All DLCs provide a power ground at Pin 4 and a clean signal ground at Pin 5. Class 2 serial data communications circuit is provided at Pin 2 of DLC.

CLASS 2 SERIAL DATA LINK

The class 2 serial data link allows a scan tool to communicate with following modules for diagnostic and testing purposes and allows following modules to communicate and share data with each other

  1. Auxiliary power drop connector.
  2. Body Control Module (BCM).
  3. Driver Information Center (DIC).
  4. Electronic Brake Control Module (EBCM).
  5. Instrument Panel Cluster (IPC).
  6. Powertrain Control Module (PCM).
  7. Radio.
  8. Remote CD player (if equipped with performance-enhanced audio).
  9. Inflatable restraint Sensing and Diagnostic Module (SDM).
  10. Vehicle Interface Unit (VIU), if equipped.

SERIAL DATA CONTROL OF RETAINED ACCESSORY POWER

Retained Accessory Power (RAP) is a vehicle power mode that permits operation of selected customer convenience items after ignition switch is turned OFF. These selected items will remain in operation until a passenger compartment door is opened or until RAP function timer reaches its shut-off limit.

Modules listed below all receive a RAP message from Body Control Module (BCM) over serial data circuits. BCM monitors ignition switch position, battery problem and passenger compartment door status to determine whether RAP should be initiated. BCM sends a message to listed modules telling them that they are in RAP power mode. Modules support operation of systems under their control as required by their RAP power mode strategy.

RAP will end when one of following conditions are met

  1. BCM receives an input (as a hard wired input from door switches) indicating opening of a passenger compartment door.
  2. BCM receives a message from its internal timer indicating end of RAP period after 10 minutes.
  3. BCM detects a decrease in battery capacity below a prescribed limit.
  4. Transition from OFF to RUN or ACC of ignition switch.

The BCM sends a serial data message to listed devices ending RAP function.

The devices receiving serial data messages for RAP functions are

  1. Auxiliary power drop connector.
  2. Driver Information Center (DIC).
  3. Instrument Panel Cluster (IPC).
  4. Radio.
  5. Remote CD player (if equipped).
  6. Vehicle Interface Unit (VIU), if equipped.

RELAY CONTROL OF RETAINED ACCESSORY POWER

Retained Accessory Power (RAP) is a vehicle power mode that permits operation of selected customer convenience items after ignition switch is turned to OFF position. These selected items will remain in operation until a passenger compartment door is opened or until RAP function timer reaches its shut-off limit.

BCM closes RAP relay in either RAP function as described above or if BCM detects a RUN or ACC power mode. This provides power for following

  1. Power windows.
  2. Sunroof control module (if equipped).

BCM opens RAP relay to end RAP function when it ends RAP function as outlined in previous text.

COMPONENT LOCATIONS

ComponentLocation
Auxiliary Power Drop ConnectorTaped In Instrument Panel Wiring Harness, Behind Right Side Of Instrument Panel
Battery Rundown Protection RelayRight Instrument Panel Fuse Block
Body Control ModuleBehind Left Side Of Instrument Panel, Above Parking Brake
Data Link ConnectorBottom Left Side Instrument Panel, Right Of Steering Column
Driver Information CenterIn Overhead Console
Electronic Brake Control ModuleLeft Side Of Engine Compartment, Mounted On ABS Hydraulic Modulator
Ignition SwitchPart Of Ignition Lock Cylinder
Inflatable Restraint & Sensing Diagnostic ModuleBelow Front Passenger Seat, Under Carpet
Instrument Panel Fuse BlockLeft Or Right Side Of Instrument Panel, In Door Opening
Intake Air Temperature SensorLeft Side Of Engine Compartment, On Air Intake Duct
Powertrain Control ModuleLeft Side Of Engine Compartment, Inside Air Filter Box
Rear Window Defogger RelayRight Instrument Panel Fuse Block
Retained Accessory Power RelayLeft Instrument Panel Fuse Block
Splice Pack SP205Next To Left Instrument Panel Fuse Block Wiring Harness, Taped To Harness
Underhood Fuse BlockOn Right Front Strut Tower

COMPONENT LOCATIONS

BODY CONTROL MODULE PROGRAMMING/REGULAR PRODUCTION OPTION CONFIGURATION

During Body Control Module (BCM) related service, use the procedures below to set-up the BCM correctly. Read these procedures carefully and completely before starting the setup procedure.

Setup New Body Control Module (BCM)

Note. Read this procedure carefully and completely. The BCM will not function properly if the Setup New BCM procedure is not performed. Perform the Programming Theft Deterrent System Components procedure after successfully finishing the Setup New BCM procedure. Refer to Programming Theft Deterrent System Components in Theft Deterrent. See PROGRAMMING THEFT DETERRENT SYSTEM COMPONENTS . If the procedure is not performed after a BCM replacement, the following conditions may occur: The vehicle will not be protected against theft by the Passlock system. The engine will not crank or start.

  1. Connect a Scan Tool (Tech 2) to the Data Link Connector (DLC).
  2. Turn the ignition switch on.
  3. Select Diagnostics and input all of the required data when prompted by the Scan Tool (Tech 2).
  4. Select BODY CONTROL MODULE.
  5. Select SPECIAL FUNCTIONS.
  6. Select Setup New BCM. NOTE: Input all of the required data when prompted by the scan tool.
  7. Select Setup SDM Part Number in BCM, and follow the onscreen directions.
  8. Select New VIN, and follow the onscreen directions.
  9. Select Option Configuration, and follow the onscreen directions.
  10. Select Point of Sale, and follow the onscreen directions.
  11. Exit back to the SPECIAL FUNCTIONS menu.
  12. When the BCM, VIN, Point of Sale and Option Configuration have been entered, proceed with the Theft Deterrent Re-learn procedure.
  13. If the scan tool displays UNABLE TO PROGRAM BCM. BCM IS SECURED, then the BCM must be replaced and this procedure must be repeated on a new BCM.

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.

Programming Replacement Passlock(tm) Sensor, BCM, or PCM

  1. The body control module (BCM) must be programmed with the proper RPO configurations before performing learn procedures. Refer to «BODY CONTROL MODULE PROGRAMMING/REGULAR PRODUCTION OPTION CONFIGURATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__body-control-module-programmingregular-production-option) .
  2. If replacing the BCM with a GM Service Parts Operations (SPO) replacement part, the module will learn Passlock(tm) sensor data code immediately. The existing PCM however, must learn the new fuel continue password when the BCM is replaced.
  3. If replacing a PCM with a GM Service Parts Operations (SPO) replacement part, after programming, these modules will learn the incoming fuel continue password immediately upon receipt of a password message. Once a password message is received, and a password is learned, a learn procedure must be performed to change this password again. A PCM which has been previously installed in another vehicle will have learned the other vehicle's fuel continue password and will require a learn procedure after programming to learn the current vehicle's password.

Conditions

Use this procedure after replacing any of the following

  1. Passlock(tm) Sensor
  2. BCM
  3. PCM

Learn Procedures

There are two available methods to perform the programming procedure

  1. A 10 minute procedure which requires a Tech 2 and a techline terminal.
  2. A 30 minutes procedure which does not require the use of any tools.

10 Minute Learn Procedure

Note. Tools Required: Tech 2, and Techline terminal with current SPS (Service Programming System) software.

  1. Connect the Tech 2 to the vehicle.
  2. Select "Request Information" under "Service Programming".
  3. Disconnect the Tech 2 from the vehicle and connect it to a techline terminal.
  4. On the techline terminal, select "Theft Module Re-Learn" under "Service Programming".
  5. Disconnect the Tech 2 from the techline terminal and connect it to the vehicle.
  6. Turn ON the ignition, with the engine OFF.
  7. Select "VTD Re-Learn" under "Service Programming".
  8. Attempt to start the engine, then release the key to ON (vehicle will not start).
  9. Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF (the vehicle is now ready to relearn the Passlock(tm) Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK).
  10. Turn OFF the ignition, and wait 5 seconds.
  11. Start the engine (the vehicle has now learned the password).
  12. With the Tech 2 (scan tool), clear any DTCs.

30 Minute Learn Procedure

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to start the engine, then release the key to ON (vehicle will not start).
  3. Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
  4. Turn OFF the ignition, and wait 5 seconds.
  5. Repeat steps 1 - 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the Passlock(tm) Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK). NOTE: The vehicle learns the Passlock(tm) Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
  6. Start the engine (the vehicle has now learned the Passlock(tm) Sensor Data Code and/or password).
  7. With a scan tool, clear any DTCs if needed (history DTCs will self clear after 100 ignition cycles).

COMPASS CALIBRATION

Note. Before calibrating compass, drive vehicle to an area that is magnetically clean (free of large metallic objects). Ensure there are no magnetic objects inside or outside of vehicle.

Compass is self calibrating. If CAL symbol is displayed on Driver Information Center (DIC). Drive vehicle in circles at a speed of less than 5 MPH for 3 complete revolutions. CAL symbol should turn off. If CAL symbol turned off, calibration is complete. If CAL symbol did not turn off, compass must be calibrated manually using following procedure

  1. Turn ignition switch to RUN position.
  2. Press MODE button until compass/temperature mode is displayed.
  3. Press and hold RESET button for about 10 seconds, or until CAL symbol is displayed.
  4. Release RESET button. Start and drive vehicle in circles at a speed of less than 5 MPH for 3 complete revolutions. When CAL symbol is no longer displayed, calibration procedure is complete.

If compass displays a constant error in heading, magnetic variation adjustments are required. See

COMPASS MAGNETIC VARIATION ADJUSTMENT

Magnetic variation adjustments are required when compass displays a constant error in heading. Variation is difference between magnetic north and true north due to geographical location.

  1. Locate your current geographic location. Refer to variation zone map. (Scheme 1)
  2. Turn ignition switch to RUN position.
  3. Press MODE button until compass/temperature mode is displayed.
  4. Press and hold RESET button for about 5 seconds, or until last entered variation zone is displayed.
  5. Press MODE button until correct zone number is displayed.
  6. Press RESET button to set new variation zone. All segments will illuminate briefly to acknowledge change in zone number.

Scheme 1

Scheme 1
Scheme 1

ENABLING AIR BAG SYSTEM

  1. Ensure left side impact air bag module connector is connected, located under driver seat. (Scheme 2)
  2. Ensure right instrument panel air bag module connector is connected, located at right side of instrument panel. (Scheme 3)
  3. Ensure steering wheel air bag module connector is connected, located at left side of instrument panel. (Scheme 4)
  4. Ensure SIR fuse is installed. Staying well away from all air bag modules, turn ignition switch to RUN position. AIR BAG indicator will flash 7 times. AIR BAG indicator will turn off. If AIR BAG indicator does not operate as described, perform air bag system diagnostic system check. See «AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__air-bag-system-diagnostic-system-check).

Scheme 2

Scheme 2
Scheme 2

Scheme 3

Scheme 3
Scheme 3

Scheme 4

Scheme 4
Scheme 4

PASSLOCK(tm) SYSTEM

Note. Body Control Module (BCM) must be programmed with proper Regular Production Option (RPO) configurations before performing learn procedures. RPO are printed on service parts identification label, located on inside of rear compartment lid. See BODY CONTROL MODULE PROGRAMMING/REGULAR PRODUCTION OPTION CONFIGURATION under PROGRAMING.

Note. When replacing BCM with original equipment GM replacement part, BCM will learn Passlock(tm) sensor data code automatically, but Powertrain Control Module (PCM) must be manually programed to new password (in order to allow crank relay and fuel injectors operation) using following procedures.

Note. When replacing PCM with original equipment GM replacement part, PCM will learn new password (in order to allow crank relay and fuel injectors operation) automatically. Once password is learned, any procedure requiring PCM to learn a new password, such as replacing BCM or Passlock(tm) sensor will require new password to be programed manually using following procedures. If a PCM is used in another vehicle, PCM will have to be manually programmed to new vehicles password using following procedures.

With Scan Tool

Note. This procedure requires a Tech 2 scan tool and a Techline(R) terminal with current Service Programming System (SPS) software.

  1. Connect Tech 2 scan tool to vehicle. Select REQUEST INFORMATION under SERVICE PROGRAMMING menu. Disconnect Tech 2 from vehicle and connect to Techline(R) terminal.
  2. On Techline(R) terminal, select THEFT MODULE RE-LEARN under SERVICE PROGRAMMING menu. Disconnect Tech 2 from Techline(R) terminal and connect to vehicle. Turn ignition switch to RUN position.
  3. Select VTD RE-LEARN under SERVICE PROGRAMMING menu. Attempt to start engine and release key to RUN position (vehicle should not start).
  4. Observe SECURITY indicator. After about 10 minutes indicator will turn OFF. Vehicle is now ready to relearn Passlock(tm) sensor data code and/or password on next ignition switch transition from OFF to CRANK position.
  5. Turn ignition switch to OFF position, and wait 5 seconds. Start engine. Vehicle has now learned password. Using scan tool, clear any DTCs.

Without Scan Tool

  1. Turn ignition switch to RUN position. Attempt to start engine and release key to RUN position, vehicle will not start.
  2. Observe SECURITY indicator, after about 10 minutes, indicator will turn OFF. Turn ignition switch to OFF position, and wait 5 seconds.
  3. Repeat steps 1 and 2 two more times for a total of 3, 30 minute, cycles. Vehicle is now ready to relearn Passlock(tm) sensor data code and/or passwords on next ignition switch transition from OFF to CRANK position.
  4. Start engine. Vehicle has now learned Passlock(tm) sensor data code and/or password. Using scan tool, clear any DTCs if needed. History DTCs will self clear after 100 ignition cycles.

POWERTRAIN CONTROL MODULE

Note. Read all procedures listed to determine why and when each procedure is to be performed before proceeding.

Crankshaft Position Sensor Variation Learn Procedure (3.4L)

  1. Procedure must be performed if any of following have been done or is present: Electronically Erasable Programmable Read Only Memory (EEPROM) was reprogrammed. If Diagnostic Trouble Code (DTC) P1336 is present. If crankshaft, crankshaft position sensor, engine, Powertrain Control Module (PCM) or vibration damper have been replaced.
  2. Crankshaft Position (CKP) sensor variation compensating values are stored in PCM after a learn procedure has been performed. If actual CKP sensor values are not within specification, DTC P0300 will be stored in PCM.
  3. Using scan tool, check for stored DTCs. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) under SELF-DIAGNOSTIC SYSTEM. Repair as necessary. If no DTCs are present, or if DTC P1336 is present, go to next step. If any DTCs are present, except for P1336, perform test procedures for specified DTC and repair as necessary. Ensure all DTCs are cleared from PCM. Go to next step.
  4. Ensure ignition is off. Apply parking brake. Block front wheels. Ensure hood is closed. Start engine and warm engine until engine coolant temperature is at least 158°F (70°C). Turn ignition switch to OFF position. NOTE: Ensure engine coolant temperature is at least 158°F (70°C) before performing CKP sensor variation learn procedure.
  5. Using scan tool, select and enable CKP sensor variation learn procedure. Start engine. Apply parking brake. Ensure transaxle is in Park.
  6. Increase accelerator pedal position until CKP system variation learn fuel cut-off is reached. CKP system variation learn fuel cut-off is reached at 5150 RPM. DO NOT release accelerator pedal until second fuel cut-off is reached. Crankshaft position system variation compensating values are learned when RPM decreases back to idle.
  7. Check scan tool for status of DTC P1336. If scan tool indicates DTC P1336 ran and passed, CKP sensor variation learn procedure is complete. If scan tool indicates DTC P1336 failed or was not run, check for any other DTCs. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If any other DTCs are present, perform test procedures for specified DTC and repair as necessary. If no other DTCs are present, repeat CKP sensor variation learn procedure.

Crankshaft Position Sensor Variation Learn Procedure (3.8L)

  1. This procedure must be performed if any of following have been done or is present: Electronically Erasable Programmable Read Only Memory (EEPROM) was reprogrammed. Diagnostic Trouble Code (DTC) P1336 is present. Crankshaft, Crankshaft Position (CKP) sensor, engine, Powertrain Control Module (PCM) or vibration damper have been replaced.
  2. Crankshaft Position (CKP) sensor variation compensating values are stored in PCM after a learn procedure has been performed. If actual CKP sensor values are not within specification, DTC P0300 will be stored in PCM.
  3. Using scan tool, check for stored DTCs. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If no DTCs are present, or if DTC P1336 is present, go to next step. If any DTCs are present, except for P1336, perform test procedures for specified DTC and repair as necessary. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. Ensure all DTCs are cleared from PCM. Go to next step.
  4. Ensure ignition is off. Apply parking brake. Block front wheels. Ensure hood is closed. Start engine and warm engine until engine coolant temperature is at least 158°F (70°C). Turn ignition switch to OFF position. NOTE: Ensure engine coolant temperature is at least 158°F (70°C) before performing CKP sensor variation learn procedure.
  5. Using scan tool, select and enable CKP sensor variation learn procedure. Start engine. Apply parking brake. Ensure transaxle is in Park.
  6. Increase accelerator pedal position until CKP system variation learn fuel cut-off is reached. CKP system variation learn fuel cut-off is reached at 4050 RPM (3.5L) or 5150 RPM (3.8L). DO NOT release accelerator pedal until second fuel cut-off is reached. Crankshaft position system variation compensating values are learned when RPM decreases back to idle.
  7. Check scan tool for status of DTC P1336. If scan tool indicates DTC P1336 ran and passed, CKP sensor variation learn procedure is complete. If scan tool indicates DTC P1336 failed or was not run, check for any other DTCs. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If any other DTCs are present, perform test procedures for specified DTC and repair as necessary. If no other DTCs are present, repeat CKP sensor variation learn procedure.

Electronically Erasable Programmable Read Only Memory Programming

  1. If Powertrain Control Module (PCM) was replaced, Electronically Erasable Programmable Read Only Memory (EEPROM) in PCM must be programmed. If EEPROM is not programmed, a Diagnostic Trouble Code (DTC) will be set in PCM.
  2. Ensure battery is fully charged. If battery is being charged, ensure battery charger is disconnected before performing EEPROM programming procedure.
  3. Ensure scan tool is properly connected on Data Link Connector (DLC). Turn ignition switch to RUN position. Perform EEPROM programming using Techline(R) equipment manufacturer's instructions and latest software applicable for vehicle model.
  4. Once EEPROM is reprogrammed, perform powertrain On-Board Diagnostic (OBD) system check. See POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. Ensure engine is idling for one minute before checking for DTCs when performing powertrain OBD system check. After EEPROM is reprogrammed, proper Crankshaft Position (CKP) sensor variation learn procedure must be performed. For 3.4L, see CRANKSHAFT POSITION (CKP) SENSOR VARIATION LEARN PROCEDURE (3.4L). For 3.8L, see CRANKSHAFT POSITION (CKP) SENSOR VARIATION LEARN PROCEDURE (3.8L). NOTE: If EEPROM programming fails, ensure all electrical connections on PCM are okay. Check Techline(R) for latest software. If EEPROM programming still fails, replace PCM.

Vehicle Driveability Computer Relearn Procedure

Manufacturer does not provide a specified computer relearn procedure for obtaining proper driveability. If vehicle battery was disconnected or Powertrain Control Module (PCM) was replaced, driving vehicle will enable PCM to perform a computer relearn procedure for obtaining proper driveability. Inform customer that driveability may differ from what they are accustomed to until PCM completes computer relearn procedure.

RADIO SETUP

  1. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. Using scan tool, select DIAGNOSTICS in MAIN MENU screen. Select MODEL YEAR and PASSENGER CAR in VEHICLE IDENTIFICATION screen. Select BODY in SYSTEM SELECTION MENU screen.
  2. Select W (for platform type), No. 1 (for Chevrolet) and appropriate vehicle in VEHICLE IDENTIFICATION screen. Select RADIO in BODY screen. Select RADIO SETUP in SPECIAL FUNCTION screen. Select appropriate radio (select up-level radio if vehicle is equipped with anything other than a base AM/FM radio). RADIO SETUP option does not contain sub-menu. RADIO SETUP will configure following systems: Steering Wheel Controls Learn VIN DTCs Class 2 Radio Messages Country Code Chime Volume Chime Level 12/24 Hour Clock

Tuner Calibration

Note. COUNTRY CODE option does not contain a sub-menu. COUNTRY CODE sets point of sale or origin of radio, in order to calibrate tuner for country that vehicle will be used in.

To calibrate radio tuner, using scan tool, go to SPECIAL FUNCTIONS screen. Select COUNTRY CODE in SPECIAL FUNCTIONS screen.

Chime Volume Selection

Note. LOUD CHIME VOLUME option does not contain a sub-menu. LOUD CHIME VOLUME is used for setting volume when radio is replaced.

To set chime volume, using scan tool, go to SPECIAL FUNCTIONS screen. Select SET OPTIONS in SPECIAL FUNCTIONS screen. Select CHIME SETTINGS in SET OPTIONS. Select LOUD CHIME VOLUME and select appropriate voltage/volume level in CHIME SETTINGS.

Chime Level Selection

Note. CHIME LEVEL option does not contain a sub-menu. CHIME LEVEL has an option of setting a normal chime or a loud chime when radio is replaced.

To set chime volume, using scan tool, go to SPECIAL FUNCTIONS screen. Select SET OPTIONS in SPECIAL FUNCTIONS screen. Select CHIME SETTINGS in SET OPTIONS. Select CHIME LEVEL in CHIME SETTINGS.

RKE TRANSMITTER PROGRAMMING

Note. All RKE transmitters recognized by RCDLR must be programmed during programming sequence. If system is placed in program mode it will erase all previously programmed RKE transmitters upon receipt of programming signal from first transmitter.

Note. Scan tool must stay connected until all of transmitters are programmed.

  1. Install a scan tool. Turn ignition switch to RUN position. Using scan tool, access Body Control Module (BCM) SPECIAL FUNCTION in PROGRAM KEY FOBS menu.
  2. Press and hold LOCK button and UNLOCK button simultaneously on one transmitter. After 15 seconds, BCM will chime in order to confirm programming of that transmitter.
  3. Repeat previous step in order to program up to 4 transmitters. Remove scan tool. Operate transmitter functions in order to verify correct system operation.
  4. Remove scan tool. Operate transmitter functions in order to verify correct system operation.

TRANSMITTER SYNCHRONIZATION

Synchronization may be necessary due to security method used by remote keyless entry system. Transmitter does not send same signal twice to Remote Control Door Lock Receiver (RCDLR). RCDLR will not respond to a signal that has been sent previously. This prevents anyone from recording and playing back signal from transmitter. Resynchronization may be necessary when, battery in transmitter is very weak, battery in transmitter was replaced, or battery in vehicle has been in a low or no charge condition for an extended period of time.

In order to synchronize transmitter with RCDLR, perform following steps

  1. Stand within 1.5 m (5 ft) from vehicle.
  2. Simultaneously press and hold LOCK and UNLOCK buttons on transmitter for 7 seconds.

Horn will chirp in order to confirm synchronization.

PRELIMINARY INSPECTION

Verify customer's complaint by operating suspect system. Visually inspect for obvious signs of electrical and/or mechanical damage. Check for blown fuses. For fuse and/or relay identification, refer to illustrations. (Scheme 5)- (Scheme 8). Check for, loose or corroded connections, damaged wiring harnesses and/or switches. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Pay special attention to harness routing where wires are hinged or make sharp bends. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. If fault is not found, perform self-diagnostics. See SELF-DIAGNOSTIC SYSTEM.

Scheme 5

Scheme 5: PRELIMINARY INSPECTION
Scheme 5: PRELIMINARY INSPECTION

Scheme 6

Scheme 6
Scheme 6

Scheme 7

Scheme 7
Scheme 7

Scheme 8

Scheme 8
Scheme 8

PROBLEM DIAGNOSIS

CAUTIONElectronic modules are sensitive to static electrical charges. Proper grounding of technician and workplace is essential to prevent damage.

Intermittent problem diagnosis requires duplication of circuit or component failure in order to identify problem. See TEST PROCEDURES . These procedures may lead to Powertrain Control Module (PCM) recording a Diagnostic Trouble Code (DTC) which may help diagnosis.

If system does not set a DTC, use scan tool or Digital Volt-Ohmmeter (DVOM) to monitor voltage or resistance values while attempting to reproduce conditions which will create an intermittent problem. See INTERMITTENT SIMULATION under TEST PROCEDURES.

When monitoring voltage, ensure specified test conditions are met. When monitoring resistance, ensure ignition switch is in LOCK position or negative battery cable is disconnected. A status change on scan tool or DVOM while performing test procedures indicates area of problem.

Intermittent Simulation

Use following methods to reproduce conditions causing intermittent problem(s)

  1. Apply light vibration to components.
  2. Apply small amount of heat to component.
  3. Wiggle or bend wiring harness.
  4. Apply/remove vacuum supply source.

Monitor circuit/component voltage or resistance while attempting to simulate intermittent. If vehicle is running, monitor for DTCs. Use test results to identify problem component or circuit.

TROUBLE SHOOTING INTERMITTENTS

Note. SERVICE ENGINE SOON light may also be referred to as Malfunction Indicator Light (MIL).

Symptom Definition

MIL comes on but does not stay on. A stored DTC may or may not be present.

Possible Causes & Corrections

Use following procedures to determine possible causes of intermittent MIL operation

  1. Check for poor mating of one connector to another. Terminals may not be fully seated. Check for improperly formed or damaged terminals. Check wire-to-terminal connections.
  2. Check for poor connection from ignition coil to ground or arcing at spark plug wires or plugs.
  3. Check for poor connections at Powertrain Control Module (PCM) ground terminals.
  4. Check for electrical system interference caused by defective relay, PCM-driven solenoid or switch, which may cause sharp electrical surge. This type of problem will normally occur when problem component is operated.
  5. Check for aftermarket parts which may not have been produced to manufacturer's specifications. Solenoids without original equipment diodes for circuit protection or voltage regulators using transistors instead of silicone-chip circuitry may cause voltage surges (up to 300 volts) in PCM wiring, causing temporary PCM shutdown. PCM shutdown is a normal response to system over voltage (over 16 volts on most models). PCM powers when problem ceases to be present. A rapid shutdown and re-power could cause a flickering MIL with no DTCs set in memory.
  6. Check for improper installation of electrical accessories such as auxiliary lights, cell phones or 2-way radios.
  7. Ensure ground wire from PCM to distributor or ignition module is connected to a good ground.
  8. Check for intermittent short to ground on data circuits of data link connector or in MIL circuit. See ENGINE PERFORMANCE article in WIRING DIAGRAMS.
  9. On vehicles not equipped with a driver information center, use scan tool to check for intermittent wiring problem. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

SELF-DIAGNOSTIC SYSTEM

CAUTIONElectronic modules are sensitive to static electrical charges. Proper grounding of technician and workplace is essential to prevent damage.

Note. Diagnostic Trouble Code (DTC) tests are written specifically for use with GM Tech 2 scan tool. Generic scan tool can be used but may have limited functions. This article only covers portion of those systems which relates to Body Control Module (BCM) system diagnosis.

BODY CONTROL MODULE SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any body control module system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Try to establish scan tool communication with Body Control Module (BCM). If communication with BCM is established, go to next step. If communication with BCM is not established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select DISPLAY DTC function for BCM. Record all displayed DTCs and status of displayed DTCs. If any DTCs are displayed, go to next step. If no DTCs are displayed, attempt to diagnose suspect system. Go to appropriate diagnostic system check for suspect system. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTC B1000, B1013 or B1015. If scan tool does not display DTC B1000, B1013 or B1015, go to next step. If scan tool displays DTC B1000, B1013 or B1015, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  6. Check for DTC B1334, B1339, B1354 or B1422. If scan tool displays DTC B1334, B1339, B1354 or B1422, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If scan tool does not display DTC B1334, B1339, B1354 or B1422, attempt to diagnose suspect system. Go to appropriate diagnostic system check for suspect system. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table.
SystemPerform Test
Air BagAIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK
Anti-Lock BrakeANTI-LOCK BRAKE SYSTEM DIAGNOSTIC SYSTEM CHECK
Audible WarningsAUDIBLE WARNINGS SYSTEM DIAGNOSTIC SYSTEM CHECK
Body Rear EndBODY REAR END SYSTEM DIAGNOSTIC SYSTEM CHECK
Cell PhoneCELLULAR COMMUNICATION SYSTEM DIAGNOSTIC SYSTEM CHECK
Cruise ControlCRUISE CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECK
DefoggersREAR WINDOW DEFOGGER SYSTEM DIAGNOSTIC SYSTEM CHECK
Engine CoolingENGINE COOLING SYSTEM DIAGNOSTIC SYSTEM CHECK
HornsHORNS SYSTEM DIAGNOSTIC SYSTEM CHECK
Instrument ClusterINSTRUMENT PANEL CLUSTER SYSTEM DIAGNOSTIC SYSTEM CHECK
Lighting SystemsLIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK
Power Door LocksDOOR SYSTEM DIAGNOSTIC SYSTEM CHECK
Power Sun RoofsPOWER SUN ROOF SYSTEM DIAGNOSTIC SYSTEM CHECK
Powertrain ControlPOWERTRAIN CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECK
Remote Keyless EntryREMOTE KEYLESS ENTRY SYSTEM DIAGNOSTIC SYSTEM CHECK
Retained Accessory PowerRETAINED ACCESSORY POWER (RAP) SYSTEM DIAGNOSTIC SYSTEM CHECK
Theft DeterrentANTI-THEFT SYSTEM DIAGNOSTIC SYSTEM CHECK
Tire Pressure MonitoringTIRE PRESSURE MONITORING SYSTEM DIAGNOSTIC SYSTEM CHECK

DIAGNOSTIC SYSTEM CHECK

AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK

WARNINGVehicles are equipped with Supplemental Inflatable Restraint (SIR) system. Before attempting any repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.

Note. Use this check as starting point for any air bag system complaint.

  1. Observe air bag indicator while turning ignition switch to RUN position. If air bag indicator flashes 7 times, go to next step. If air bag indicator does not flash 7 times, diagnose air bag system problem.
  2. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  3. Turn ignition switch to RUN position. Try to establish scan tool communication with inflatable restraint Sensing and Diagnostic Module (SDM). If communication with SDM is established, go to next step. If communication with SDM is not established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  4. Select DISPLAY DTC function for SDM. Record all displayed DTCs and status of displayed DTCs. If any DTCs current are displayed, go to next step. If no current DTCs are displayed, system is okay.
  5. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  6. Check for DTC B1000. If scan tool displays DTC B1000, go to «DTC B1000: CONTROL MODULE MALFUNCTION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under DIAGNOSTIC TESTS. If scan tool does not display DTC B1000, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

ANTI-LOCK BRAKE SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. When using scan tool for diagnostics, Anti-Lock Brake System (ABS)/Enhanced Traction System (ETS) system is disabled by Electronic Brake Control Module (EBCM). ANTI-LOCK indicator will illuminate indicating only normal power assist braking is available. After diagnostics have been completed, disconnect scan tool from Data Link Connector (DLC) and turn ignition off for a least 10 seconds before road testing. This procedure is done to reset EBCM.

Note. Use this check as starting point for any anti-lock brake system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition on, with engine off. Using scan tool, attempt to establish communication with BCM, EBCM, IPC and PCM. If scan tool communicates with all control modules, go to next step. If scan tool does not communicate with all control modules, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select DTCs function on scan tool for BCM, EBCM, IPC or PCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, diagnose by symptom. See «SYSTEM TESTS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__system-tests) .
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTC B1000 or B1013. If scan tool displays DTC B1000 or B1013, diagnose affected DTCs. Go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If DTC B1000 or B1013 is not displayed, go to next step.
  6. Check for DTC P0560 or P0620. If scan tool displays DTC P0560 or P0620, diagnose affected DTCs. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If DTC P0560 or P0620 is not displayed, diagnose affected DTC(s) displayed.

ANTI-THEFT SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any anti-theft system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Connect scan tool to Data Link Connector (DLC). Using scan tool, attempt to establish communication with Body Control Module (BCM) and Powertrain Control Module (PCM). If scan tool communicates with BCM and PCM, go to next step. If scan tool does not communicate with BCM and PCM, see «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Using scan tool, retrieve DTCs. If BCM and PCM DTCs are present, go to next step. If scan tool does not display any DTCs, perform appropriate symptom test. See SYSTEM TESTS in appropriate ANTI-THEFT SYSTEM article.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Using scan tool, retrieve DTCs. If DTCs P0601 or P0602 is present, see appropriate BODY CONTROL MODULES article. If DTCs P0601 and P0602 are not present, go to next step.
  6. Check for DTCs B1000, B1007 or B1009. If DTCs B1000, B1007 or B1009 is present, see appropriate BODY CONTROL MODULES article. If DTCs B1000, B1007 and B1009 are not present, go to next step.
  7. Check for DTCs B1327 or B1328. If DTCs B1327 or B1328 is present, see appropriate BODY CONTROL MODULES article. If DTCs B1327 and B1328 are not present, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

AUDIBLE WARNINGS SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any audible warnings system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with following modules: Body Control Module (BCM) Powertrain Control Module (PCM) Electronic Brake Control Module (EBCM) Inflatable Restraint & Sensing Diagnostic Module (SDM) Radio If communication is established with all modules, go to next step. If communication cannot be established any module, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select scan tool display DTCs function for following control modules: Body Control Module (BCM) Powertrain Control Module (PCM) Electronic Brake Control Module (EBCM) Inflatable Restraint Sensing & Diagnostic Module (SDM) If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, perform appropriate procedure in appropriate ANALOG INSTRUMENT PANELS article.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTCs B1000, B1007, B1009, B1339, B1349 or B1440. If DTCs are not present, go to next step. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  6. Check for DTCs B1482, B1483, B1507, B1508, P0560 or P0620. If DTCs are not present, test is complete. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

BODY REAR END SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any body rear end system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Try to establish scan tool communication with Body Control Module (BCM). If communication with BCM is established, go to next step. If communication with BCM is not established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select DISPLAY DTC function for BCM. Record all displayed DTCs and status of displayed DTCs. If any DTCs are displayed, go to next step. If no DTCs are displayed, repair trunk release system as necessary. See appropriate POWER DOOR LOCKS & TRUNK RELEASE article.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTC B1000. If DTC is not present, go to next step. If DTC B1000 is present, go to «DTC B1000: CONTROL MODULE MALFUNCTION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under DIAGNOSTIC TESTS.
  6. Check for DTC B1295. If scan tool displays DTC C1295, perform appropriate test. See appropriate ANTI-LOCK article in BRAKES. If scan tool does not display DTC C1295, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

CELLULAR COMMUNICATION SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any cellular communication system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with Vehicle Interface Unit (VIU). If communication is established, go to next step. If communication cannot be established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select VIU DTCS function on scan tool. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair as necessary.
  4. Using scan tool, check for DTCs U1000-U1305. If DTCs are present, go to next step. If DTCs are not present, go to step 6 .
  5. Check for DTC B1500. If DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If DTC B1500 is not present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  6. Check for DTCs B1000, B1004, B1007 or B1009. If DTCs are not present, go to next step. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  7. Check for DTCs B1327 or B1328. If DTCs are not present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . If DTCs are present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

CRUISE CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any cruise control system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with Powertrain Control Module (PCM). If communication is established, go to next step. If communication cannot be established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select PCM DTCS function on scan tool. If scan tool displays any cruise control DTCs, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If scan tool does not display any cruise control DTCs, repair as necessary.

DOOR SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any door system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with Body Control Module (BCM). If communication is established, go to next step. If communication cannot be established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select BODY CONTROL MODULE DTCS function on scan tool. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, perform appropriate procedure in appropriate POWER DOOR LOCKS article.
  4. Using scan tool, check for DTCs U1000-U1305. If DTCs are not present, go to next step. If DTCs are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTC B1000. If DTC is not present, go to next step. If DTC B1000 is present, go to «DTC B1000: CONTROL MODULE MALFUNCTION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under DIAGNOSTIC TESTS.
  6. Check for DTCs B1339 or B1349. If DTCs are not present, go to next step. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  7. Check for DTCs beginning with a "P". If DTCs beginning with a "P" are not present, go to next step. If DTCs beginning with a "P" are present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  8. Check for DTCs B3069, B3127, B3128, B3132, B3133, B3137, B3138 or B3272. If DTCs are not present, perform appropriate symptom test. See SYSTEM TESTS in appropriate POWER DOOR LOCKS & TRUNK RELEASE article. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

DRIVER INFORMATION CENTER SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any driver information center system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with Driver Information Center (DIC). If communication is established, go to next step. If communication cannot be established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select DRIVER INFORMATION CENTER DISPLAY DTCS function on scan tool. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, perform appropriate procedure in appropriate ANALOG INSTRUMENT PANELS article.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTCs B1000, B1007, B1009, B1339, B1349 or B1440. If DTCs are not present, go to next step. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  6. Check for DTCs B1482, B1483, B1507, B1508, P0560 or P0620. If DTCs are not present, test is complete. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

ENGINE COOLING SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any engine cooling system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Try to establish scan tool communication with Instrument Panel Cluster (IPC) and Powertrain Control Module (PCM). If communication with IPC and PCM is established, go to next step. If communication with IPC and/or PCM is not established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select DISPLAY DTC function for PCM. Record all displayed DTCs and status of displayed DTCs. If any DTCs are displayed, go to next step. If no DTCs are displayed, repair cooling system as necessary.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.

ENGINE ELECTRICAL SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any engine electrical system complaint.

  1. Ensure battery is in good operating condition. See appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. Repair as necessary. If battery is okay, go to next step.
  2. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  3. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with following modules: Body Control Module (BCM) Powertrain Control Module (PCM) Electronic Brake Control Module (EBCM) Inflatable Restraint & Sensing Diagnostic Module (SDM) Radio If communication is established with all modules, go to next step. If communication cannot be established any module, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  4. Select scan tool display DTCs function for following control modules: Body Control Module (BCM) Powertrain Control Module (PCM) Electronic Brake Control Module (EBCM) Inflatable Restraint Sensing & Diagnostic Module (SDM) If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, perform appropriate symptom test. See SYSTEM TESTS in appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS.
  5. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  6. Check for DTC B1000, B2058, B2947, B2948, B2957, B2960, B3031 or B3032. If scan tool displays DTC B1000, B2058, B2947, B2948, B2957, B2960, B3031 or B3032, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If scan tool does not display DTC B1000, B2058, B2947, B2948, B2957, B2960, B3031 or B3032, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

HORNS SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any horns system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with Body Control Module (BCM). If communication is established, go to next step. If communication cannot be established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select BCM DTCS function on scan tool. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, perform appropriate symptom test. See SYSTEM TESTS in appropriate STEERING COLUMN SWITCHES article.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTCs B1000 or B1004. If DTCs are not present, go to next step. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  6. Check for DTCs B1339 or B1349. If DTCs are not present, go to next step. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  7. Check for DTCs B1482, B1483, B1507 or B1508. If DTCs are not present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

INSTRUMENT PANEL CLUSTER SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any instrument panel cluster system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with following modules: Body Control Module (BCM) Powertrain Control Module (PCM) Electronic Brake Control Module (EBCM) Inflatable Restraint & Sensing Diagnostic Module (SDM) If communication is established with all modules, go to next step. If communication cannot be established any module, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select scan tool display DTCs function for following control modules: Body Control Module (BCM) Powertrain Control Module (PCM) Electronic Brake Control Module (EBCM) Instrument Panel Cluster (IPC) Inflatable Restraint Sensing & Diagnostic Module (SDM) If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, perform appropriate symptom test. See SYSTEM TESTS in appropriate ANALOG INSTRUMENT PANELS article.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTCs B1000, B1007, B1009, B1339, B1349 or B1440. If DTCs are not present, go to next step. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  6. Check for DTCs B1482, B1483, B1507, B1508, P0560 or P0620. If DTCs are not present, test is complete. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any lighting system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with Driver Information Center (DIC). If communication is established, go to next step. If communication cannot be established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select DISPLAY DTC function for BCM. Record all displayed DTCs and status of displayed DTCs. If any DTCs are displayed, go to next step. If no DTCs are displayed, attempt to diagnose suspect system. Go to appropriate system check for suspect system. See «SYSTEM TESTS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__system-tests) .
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTC B1000. If DTC is not present, go to next step. If DTC B1000 is present, go to «DTC B1000: CONTROL MODULE MALFUNCTION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under DIAGNOSTIC TESTS.

POWER SEATS SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any power seats system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with Body Control Module (BCM) and Powertrain Control Module (PCM). If communication is established, go to next step. If communication cannot be established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select scan tool display DTCs function for BCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, perform appropriate symptom. See SYSTEM TESTS in appropriate POWER SEATS article.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  5. Check for DTC B1000 or B1339. If scan tool displays DTC B1000 or B1339, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If scan tool does not display DTC B1000 or B1339, go to next step.
  6. Check for DTC B0506. If scan tool displays DTC B0506, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If scan tool does not display DTC B0506, perform appropriate symptom test. See SYSTEM TESTS in appropriate POWER SEATS article.

POWER SUN ROOF SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any power sun roof system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to communicate with Body Control Module (BCM). If communication with BCM is possible, go to next step. If communication with BCM is not possible, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select BCM display DTCs function. Scan tool should display NO DTCS FOUND. If any DTCs are listed, go to next step. If scan tool does not display any DTCs, perform appropriate symptom test. See SYSTEM TESTS in appropriate POWER SUN ROOFS article.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  5. Check for DTC B1000. If scan tool displays DTC B1000, go to «DTC B1000: CONTROL MODULE MALFUNCTION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under DIAGNOSTIC TESTS. If scan tool does not display DTC B1000, go to next step.
  6. Check for DTC B1477 or B1478. If scan tool displays DTC B1477 or B1478, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If scan tool does not display DTC B1477 or B1478, go to next step.
  7. Check for DTC B1507 or B1508. If scan tool displays DTC B1507 or B1508, perform appropriate test. See appropriate GENERATORS & REGULATORS article. If scan tool does not display any DTCs, perform appropriate symptom test. See SYSTEM TESTS in appropriate POWER SUN ROOFS article.

POWERTRAIN CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. DO NOT perform this diagnostic if there is not a driveability condition, unless another procedure directs you to this diagnostic. Before you proceed with diagnosis, search for applicable service bulletins. Unless a diagnostic procedure instructs you, DO NOT clear DTCs. If there is a problem with starting system, see ENGINE ELECTRICAL SYSTEM DIAGNOSTIC SYSTEM CHECK . Ensure battery is fully charged. Ensure battery cables are clean and tight. Ensure Powertrain Control Module (PCM) grounds are clean, tight, and in correct location.

Note. Use this check as starting point for any powertrain control system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Try to establish scan tool communication with Powertrain Control Module (PCM), Body Control Module (BCM), Instrument panel cluster and Electronic Brake Control Module (EBCM). If communication with all modules is established, go to next step. If communication with all modules is not established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Attempt to start and idle engine. If engine starts and idles, go to next step. If engine does not start and idle, repair by symptom. See appropriate TROUBLE SHOOTING - NO CODES article in ENGINE PERFORMANCE.
  4. Select DISPLAY DTC function for each module. Record all displayed DTCs and status of displayed DTCs. If any DTCs are displayed, go to next step. If no DTCs are displayed, go to step 9 .
  5. Using scan tool, select CAPTURED INFO function to store PCM DTC information. After storing PCM DTC information, go to next step.
  6. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  7. Check for DTCs P0601 or P0602. If scan tool does not display DTCs, go to next step. If scan tool displays DTCs, perform appropriate test. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
  8. Check for DTCs P0560 or P0620. If scan tool displays DTCs, see appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. If scan tool does not display DTCs, perform appropriate test. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
  9. Is customer's concern transmission-related. If customer's concern is not transmission-related, go to next step. If customer's concern is transmission-related, see appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS or MANUAL TRANSMISSIONS.
  10. Is customer's concern Inspection/Maintenance (I/M) testing-related. If customer's concern is not Inspection/Maintenance (I/M) testing-related, go to next step. If customer's concern is I/M testing-related, repair by symptom. See appropriate TROUBLE SHOOTING - NO CODES article in ENGINE PERFORMANCE.
  11. If customer's concern is hard start surges, lack of power, sluggishness, sponginess, detonation/spark knock hesitation, sag, stumble, cuts out, misses poor fuel economy, poor fuel fill quality, rough idle, unstable idle, incorrect idle, stalling, dieseling, run-on, backfire, MIL always on or MIL inoperative, repair by symptom. See appropriate TROUBLE SHOOTING - NO CODES article in ENGINE PERFORMANCE. If no symptoms are present, system is okay.

RADIO/AUDIO SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any radio/audio system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Connect scan tool to Data Link Connector (DLC). Try to establish scan tool communication with radio and remote CD changer (if equipped). If communication with radio and remote CD changer (if equipped) is established, go to next step. If communication with radio and remote CD changer (if equipped) is not established, see «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Using scan tool, select DISPLAY DTCs function for radio and remote CD changer (if equipped). If any DTCs are listed, go to next step. If no DTCs are listed, go to repair as necessary.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If DTCs U1000-U1305 are present, see «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.

REAR WINDOW DEFOGGER SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any rear window defogger system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with Body Control Module (BCM). If communication is established, go to next step. If communication cannot be established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select BODY CONTROL MODULE DTCS function on scan tool. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, perform appropriate symptom test. See SYSTEM TESTS in appropriate REAR WINDOW & MIRROR DEFOGGERS article.
  4. Using scan tool, check for DTCs U1000-U1305. If DTCs are not present, go to next step. If DTCs are present, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTC B1000. If DTC is not present, go to next step. If DTC B1000 is present, go to «DTC B1000: CONTROL MODULE MALFUNCTION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under DIAGNOSTIC TESTS.
  6. Check for DTCs B1327, B1328, B1507 or B1508. If scan tool does not display any DTCs, perform appropriate symptom test. See SYSTEM TESTS in appropriate REAR WINDOW & MIRROR DEFOGGERS article. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

REMOTE KEYLESS ENTRY SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any remote keyless entry system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Connect scan tool to Data Link Connector (DLC). Try to establish scan tool communication with Body Control Module (BCM). If communication with BCM is established, go to next step. If communication with BCM is not established, see «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Using scan tool, select DISPLAY DTCs function for BCM. Record all displayed DTCs and status of displayed DTCs. If DTCs are present, go to next step. If scan tool does not display any DTCs, perform appropriate symptom test. See SYSTEM TESTS in appropriate REMOTE KEYLESS ENTRY SYSTEMS article.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, see «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  5. Check for DTC B1000 or B1004. If scan tool does not display DTC B1000 or B1004, go to next step. If scan tool displays DTCs B1000 or B1004, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  6. Check for DTC B1339 or B1349. If scan tool does not display DTC B1339 or B1349, go to next step. If scan tool displays DTCs B1339 or B1349, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  7. Check for DTC B1482, B1483, B1507 or B1508. If scan tool does not display DTC B1482, B1483, B1507 or B1508, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . If scan tool displays DTC B1482, B1483, B1507 or B1508, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

RETAINED ACCESSORY POWER SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any retained accessory power system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to establish communication with Body Control Module (BCM). If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select DISPLAY DTCs function for BCM. If any DTCs are present, go to next step. If no DTCs are present, go to appropriate symptom test. See «SYSTEM TESTS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__system-tests) .
  4. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  5. Check for DTCs B1000, B1339 or B1349. If DTCs are not present, go to next step. If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.
  6. Check for DTCs B1477 or B1478. If DTCs are not present, go to appropriate symptom test. See «SYSTEM TESTS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__system-tests) . If any DTC is present, go to «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary.

TIRE PRESSURE MONITORING SYSTEM DIAGNOSTIC SYSTEM CHECK

Note. Use this check as starting point for any tire pressure monitoring system complaint.

  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Try to establish scan tool communication with Electronic Brake Control Module (EBCM). If communication with EBCM is established, go to next step. If communication with EBCM is not established, go to «TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under SYSTEM TESTS.
  3. Select DISPLAY DTC function for DRP/ABS/TCS/TIM/VSES (if equipped). If scan tool does not display any DRP/ABS/TCS/TIM/VSES DTCs, go to next step. If scan tool displays any DRP/ABS/TCS/TIM/VSES DTCs, go to «ANTI-LOCK BRAKE SYSTEM DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__anti-lock-brake-system-diagnostic-system-check) .
  4. Using scan tool check for DTCs. If scan tool displays DTC C1245, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) . Repair as necessary. If scan tool does not display DTC C1245, system is okay.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DTCDescription(1) Perform Test
B0012Right Instrument Panel Air Bag Stage 2 Deployment Loop Resistance Low(2)
B0013Right Instrument Panel Air Bag Stage 2 Deployment Loop Voltage Low(2)
B0014Right Instrument Panel Air Bag Stage 2 Deployment Loop Voltage High(2)
B0016Right Instrument Panel Air Bag Stage One Deployment Loop Resistance Low(2)
B0017Right Instrument Panel Air Bag Stage One Deployment Loop Voltage Low(2)
B0018Right Instrument Panel Air Bag Stage One Deployment Loop Voltage High(2)
B0022Steering Wheel Air Bag Stage One Deployment Loop Resistance Low(2)
B0024Steering Wheel Air Bag Stage One Deployment Loop Voltage High(2)
B0026Steering Wheel Air Bag Stage One Deployment Loop Voltage Low(2)
B0034Left Side Impact Air Bag Deployment Commanded(2)
B0040Left Side Impact Air Bag Deployment Loop Resistance Low(2)
B0041Left Side Impact Air Bag Deployment Loop Voltage Low(2)
B0042Steering Wheel Air Bag Stage 2 Deployment Loop Resistance Low(2)
B0043Steering Wheel Air Bag Stage 2 Deployment Loop Voltage Out Of Range(2)
B0044Steering Wheel Air Bag Stage 2 Deployment Loop Voltage Low(2)
B0045Left Side Impact Air Bag Deployment Loop Voltage Out Of Range(2)
B0051Air Bag Deployment Commanded(2)
B0053Air Bag Deployment Commanded With Loop Malfunctions Present(2)
B0077No Communication Between Inflatable Restraint Sensing & Diagnostic Module, & Side Impact Sensor(2)
B0079Incorrect ID Sent To Inflatable Restraint Sensing & Diagnostic Module By Side Impact Sensor(2)
B0080Not Okay Message Sent To Inflatable Restraint Sensing & Diagnostic Module By Side Impact Sensor(2)
B0100No Communication Between Inflatable Restraint Sensing & Diagnostic Module, & Electronic Frontal Sensor(2)
B0101Not Okay Message Sent To Inflatable Restraint Sensing & Diagnostic Module By Electronic Frontal Sensor(2)
B0102Incorrect ID Sent To Inflatable Restraint Sensing & Diagnostic Module By Electronic Frontal Sensor(2)
B0160Ambient Air Temperature Sensor Circuit Low(3)
B0162Temperature Sensor Circuit Open(3)
B0931Compass Sensor Circuit Malfunction(3)
B1000Control Module MalfunctionB1000
B1001Incorrect Setup Information(3)
B1003Programming Mode Active Message Not Received(6)
B1007Electronically Erasable Programmable Read Only Memory Write ErrorB1007
B1009Checksum Error In Control ModuleB1009
B1339Device Power No. 3 Circuit OpenB1339
B1349Device Ground No. 1 (Chassis Ground No. 1) Circuit OpenB1349
B1440Power Mode Master Input Circuit MismatchB1440
B1447Retained Accessory Power Circuit LowB1447
B1478Retained Accessory Power Circuit HighB1478
B1482Battery Rundown Protection Circuit Low(14)
B1483Battery Rundown Protection Circuit High(14)
B1507High Power Control Circuit Low(14)
B1508High Power Control Circuit High(14)
B1780Incorrect VIN Information(7)
B2462Vehicle Interface Unit Does Not Detect GPS Signal(8)
B2476Low OnStar(R) Keypad Voltage, Ignition Switch In RUN Or ACC Position(9)
B2532Short Or Open In Fog Light Relay Coil Control Circuit, Relay Not Energized(4)
B2533Short To Power In Fog Light Relay Coil Control Circuit, Relay Energized(4)
B2552Short To Ground Or Open In Backup Light Relay Coil Control Circuit, Relay Not Energized(4)
B2553Short To Power In Backup Light Relay Coil Control Circuit, Relay Energized(4)
B2577Short To Ground Or Open In Headlight Relay Coil Control Circuit, Relay Not Energized(4)
B2578Short To Power In Headlight Relay Coil Control Circuit, Relay Energized(4)
B2582Short To Ground Or Open In High Beam Indicator Control Signal Circuit, Headlights & DRL Off(4)
B2587Short To Ground Or Open In Park Light Relay Coil Control Circuit, Relay Not Energized(4)
B2588Short To Power In Park Light Relay Coil Control Circuit, Relay Energized(4)
B2602Short To Ground Or Open In DRL Relay Coil Control Circuit(4)
B2603Short To Power In DRL Relay Coil Control Circuit(4)
B2617Footwell Lights Dimming Control Circuit Output, Low(5)
B2618Footwell Lights Dimming Control Circuit Output, High(5)
B2647Short To Ground In Headlight Auto Control Ambient Light Ground Reference Circuit(4)
B2648Open DRL Ambient Light Sensor Signal Circuit, Automatic headlight On(4)
B2650Short To Ground Or Open In High Bear Indicator Control Signal Circuit(4)
B2651Short To Ground Or Open In High Beam Indicator Control Signal Circuit, Headlights & DRL Off(4)
B2654Theater Dimming Ground Circuit Output, Low(5)
B2655Short To Power In Interior Lights Dimming Control Output Circuit(5)
B2665Short To Power Or Open In Park Light Circuit, Headlight Switch Is In HEAD Position(4)
B2742Short To Ground In Fog Light Switch Signal Circuit(4)
B2753Horn Relay Coil Circuit High(10)
B2823Trip Odometer Reset Switch Circuit Low(3)
B2947Passlock(tm) Sensor Power Circuit Low(12)
B2948Passlock(tm) Sensor Power Circuit High(12)
B2957Passlock(tm) Sensor Data Circuit Low(12)
B2958Passlock(tm) Sensor Data Circuit High(12)
B2960Passlock(tm) Sensor Data Incorrect But Valid(12)
B2964Incorrect Ignition Lock Cylinder Signal Voltage Input(3)
B3031Controller In Learn Mode(12)
B3033System Indicates Tamper(12)
B3069Driver Door Lock Cylinder Switch Signal Circuit Low(11)
B3102Keyless Entry Data Link Circuit Low(6)
B3103Keyless Entry Data Link Circuit Low(6)
B3106Keyless Entry Data Link Parity Error(6)
B3127Door Lock Actuator Circuit Low(11)
B3128Door Lock Actuator Circuit High(11)
B3132Door Lock Actuator Circuit Low(11)
B3133Door Lock Actuator Circuit High(11)
B3137Door Lock Actuator Circuit Low(11)
B3138Door Lock Actuator Circuit High(11)
B3247Short To Ground In Trunk Release Circuit(11)
B3248Short To Power In Trunk Release Circuit(11)
B3272Driver Door Lock Switch Unlock Signal Circuit Low(11)
B3895Short To Ground In Trunk Open Switch Circuit(11)
B3896Open Or Short To Power In Trunk Release Circuit(11)
B3898No Communication To Body Control Module From Rear Compartment Occupant Sensor(11)
B3904Body Control Module Receives An Invalid Signal From Rear Compartment Occupant Sensor(11)
CXXXXAnti-Lock Brake System Fault(13)
C1245Low Tire Pressure Detected(3)
P0462Fuel Level Signal Voltage Low(3)
P0463Fuel Level Signal Voltage High(3)
P1189Oil Pressure Switch Signal Voltage Is High(3)
P1554PCM Inhibiting Cruise Control Operation(15)
P1585Cruise Control Inhibit Signal Circuit, Improper Voltage(15)
P1626No Or Incorrect Fuel Enable Signal, With Engine Running(12)
P1629No Or Incorrect Fuel Enable Signal, With Engine Cranking(12)
P1630PCM Remains In Password Learn Mode For More Than 2 Seconds(12)
P1631PCM Detects Incorrect Password, Anti-Theft System Failure Or Attempted Vehicle Theft(12)
PXXXXPowertrain Control Module Fault(16)
DTC U1000 & U1255Class 2 Communication MalfunctionDTC U1000 & U1255
U1001-U1254Loss Of XXX CommunicationsU1001-U1254
U1300Class 2 Data Link Shorted To GroundU1300
U1301Class 2 Data Link Shorted To PowerU1301
Class 2 Data Link Shorted To Ground/PowerU1305
U1500No Communication Between Vehicle Interface Unit & Vehicle Communication Unit, Ignition Switch In RUN Of ACC Position(9)
(1) Unless otherwise instructed, perform appropriate test under DIAGNOSTIC TESTS. (2) For information on air bag DIAGNOSIS & TESTING or DISPOSAL PROCEDURES, see MITCHELL(R) AIR BAG SERVICE & REPAIR MANUAL, DOMESTIC & IMPORTED MODELS. (3) See appropriate ANALOG INSTRUMENT PANELS article. (4) See appropriate EXTERIOR LIGHTS article. (5) See appropriate ILLUMINATION/INTERIOR LIGHTS article. (6) See appropriate REMOTE KEYLESS ENTRY SYSTEMS article. (7) Repair entertainment system as necessary. (8) Repair global positioning system as necessary. (9) Repair cellular phone system as necessary. (10) See appropriate STEERING COLUMN SWITCHES article. (11) See appropriate POWER DOOR LOCKS & TRUNK RELEASE article. (12) See appropriate ANTI-THEFT SYSTEMS article. (13) See appropriate ANTI-LOCK article in BRAKES. (14) See appropriate Generators & Regulators article in STARTING & CHARGING SYSTEMS. (15) See appropriate CRUISE CONTROL SYSTEMS article. (16) For powertrain control module diagnostic trouble code descriptions and testing procedures not listed, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
(1)Unless otherwise instructed, perform appropriate test under DIAGNOSTIC TESTS.
(2)For information on air bag DIAGNOSIS & TESTING or DISPOSAL PROCEDURES, see MITCHELL(R) AIR BAG SERVICE & REPAIR MANUAL, DOMESTIC & IMPORTED MODELS.
(3)See appropriate ANALOG INSTRUMENT PANELS article.
(4)See appropriate EXTERIOR LIGHTS article.
(5)See appropriate ILLUMINATION/INTERIOR LIGHTS article.
(6)See appropriate REMOTE KEYLESS ENTRY SYSTEMS article.
(7)Repair entertainment system as necessary.
(8)Repair global positioning system as necessary.
(9)Repair cellular phone system as necessary.
(10)See appropriate STEERING COLUMN SWITCHES article.
(11)See appropriate POWER DOOR LOCKS & TRUNK RELEASE article.
(12)See appropriate ANTI-THEFT SYSTEMS article.
(13)See appropriate ANTI-LOCK article in BRAKES.
(14)See appropriate Generators & Regulators article in STARTING & CHARGING SYSTEMS.
(15)See appropriate CRUISE CONTROL SYSTEMS article.
(16)For powertrain control module diagnostic trouble code descriptions and testing procedures not listed, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DIAGNOSTIC TESTS

WARNINGVehicles are equipped with Supplemental Inflatable Restraint (SIR) system. Before attempting ANY repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.
CAUTIONElectronic modules are sensitive to static electrical charges. Proper grounding of technician and workplace is essential to prevent damage.

Note. DO NOT replace Body Control Module (BCM) unless a DTC remains current after all DTC repairs have been performed. DO NOT replace BCM if only history DTCs are set.

Note. Always check module ground and power circuits prior to replacing a control module. See GROUND DISTRIBUTION and/or POWER DISTRIBUTION articles in WIRING DIAGRAMS.

Description

Internal fault detection is handled inside control module. No external circuits are involved. DTC B1000 is set when, control module detects an internal write error or an internal check-sum error. When DTC B1000 is set, microprocessor refuses all additional inputs. Current DTC B1000 will clear and become a history DTC when microprocessor makes a successful write to Electronically Erasable Programmable Read Only Memory (EEPROM) and check-sum maneuver. History DTC B1000 will clear after 100 consecutive ignition cycles if problem for malfunction is no longer present.

Code Enable Criteria

Following criteria must be met to enable DTC; control module runs a program to detect an internal fault when power up is commanded. Only requirements are voltage and ground.

Conditions For Setting The DTC

  1. The control module detects an internal write malfunction.
  2. The control module detects an internal checksum malfunction.

Action Taken When The DTC Sets

  1. 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.

Testing

  1. Perform diagnostic system check for suspect system control module. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table under SELF-DIAGNOSTIC SYSTEM. Repair as necessary and go to step 4 . If diagnostic system check has been performed for suspect system control module, go to next step.
  2. Check if DTC B1000 was set as a current DTC. If DTC B1000 was set as a current DTC, go to next step. If DTC B1000 was not set as a current DTC go to «DIAGNOSTIC AIDS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-aids) before proceeding to next step.
  3. Replace, suspect control module. Program and configure new control module. Go to next step.
  4. Using scan tool, clear DTCs. Operate vehicle within «CODE ENABLE CRITERIA»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__code-enable-criteria) conditions. Using scan tool, retrieve DTCs. If DTC B1000 resets, return to step 2 . If DTC B1000 does not reset, system is okay.

Diagnostic Aids

This DTC may be stored as a history DTC without affecting operation of module. If stored only as a history DTC and not set as a current DTC, DO NOT replace module. If this DTC is set as both a Current and History DTC, replace module.

Internal fault detection is handled inside control module. No external circuits are involved. DTC B1007 is set when, control module detects an internal write error. When DTC B1007 is set, microprocessor refuses all additional inputs. Current DTC B1007 will clear and become a history DTC when microprocessor makes a successful write to Electronically Erasable Programmable Read Only Memory (EEPROM). History DTC B1007 will clear after 100 consecutive ignition cycles if problem for malfunction is no longer present.

Following criteria must be met to enable DTC; control module runs a program to detect a write error to memory when a power mode change is commanded. Only requirements are voltage and ground.

  1. 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.
  1. 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.
  1. Perform diagnostic system check for suspect system control module. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table under SELF-DIAGNOSTIC SYSTEM. Repair as necessary and go to step 4 . If diagnostic system check has been performed for suspect system control module, go to next step.
  2. Check if DTC B1007 was set as a current DTC. If DTC B1007 was set as a current DTC, go to next step. If DTC B1007 was not set as a current DTC go to «DIAGNOSTIC AIDS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) before proceeding to next step.
  3. Replace, suspect control module. Program and configure new control module. Go to next step.
  4. Using scan tool, clear DTCs. Operate vehicle within «CODE ENABLE CRITERIA»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) conditions. Using scan tool, retrieve DTCs. If DTC B1007 resets, return to step 2 . If DTC B1007 does not reset, system is okay.

This DTC may be stored as a history DTC with out affecting operation of module. If stored only as a history DTC and not set as a current DTC, DO NOT replace module. If this DTC is set as both a Current and History DTC, replace module.

Internal fault detection is handled inside control module. No external circuits are involved. DTC B1009 is set when control module detects a check-sum error in internal memory. When DTC B1009 is set, microprocessor refuses all additional inputs. Current DTC B1009 will clear and become a history DTC when microprocessor makes a successful check-sum maneuver with Electronically Erasable Programmable Read Only Memory (EEPROM). History DTC B1009 will clear after 100 consecutive ignition cycles if problem for malfunction is no longer present.

Following criteria must be met to enable DTC; control module runs a program to detect a check-sum error in memory when a power mode change is commanded. Only requirements are voltage and ground.

  1. 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.
  1. 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.
  1. Perform diagnostic system check for suspect system control module. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table under SELF-DIAGNOSTIC SYSTEM. Repair as necessary and go to step 4 . If diagnostic system check has been performed for suspect system control module, go to next step.
  2. Check if DTC B1009 was set as a current DTC. If DTC B1009 was set as a current DTC, go to next step. If DTC B1009 was not set as a current DTC go to «DIAGNOSTIC AIDS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) before proceeding to next step.
  3. Replace, suspect control module. Program and configure new control module. Go to next step.
  4. Using scan tool, clear DTCs. Operate vehicle within «CODE ENABLE CRITERIA»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) conditions. Using scan tool, retrieve DTCs. If DTC B1009 resets, return to step 2 . If DTC B1009 does not reset, system is okay.

This DTC may be stored as a history DTC with out affecting operation of module. If stored only as a history DTC and not set as a current DTC, DO NOT replace module. If this DTC is set as both a Current and History DTC, replace module.

Body Control Module (BCM) monitors condition of load battery voltage supply circuits. When BCM receives 9-16 volts from CLSTR/BCM fuse, BCM tests to verify voltage and grounds are present for BCM outputs. Battery feed circuit, from HTD SEAT fuse, provides power for following items

  1. Heated Seats
  2. Retained Accessory Power (RAP) Relay Coil
  3. Rear Defogger Relay Coil

Battery feed circuit, from DR LK fuse to BCM, provides power for following items

  1. Door Locks
  2. Trunk Release Motor

Following criteria must be met to enable DTC; voltage on battery feed circuit, from CLSTR/BCM fuse to BCM must be between 9-16 volts.

The BCM must detect

  1. The B+ supply circuit for load and RAP functions is less than 1 volt
  2. The B+ supply circuit for the lock and trunk release functions is less than 1 volt
  3. The above conditions last for more than 300 milliseconds
  1. The lock and release functions may not operate.
  2. The defrost functions for the rear window and the exterior mirrors may not operate.
  3. The heated seats may not operate.
  4. The BCM stores DTC B1339 in memory.
  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. Perform diagnostic system check for suspect system control module. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table under SELF-DIAGNOSTIC SYSTEM. Repair as necessary and go to step 6 . If diagnostic system check has been performed for suspect system control module, go to next step.
  2. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Switch to BCM input data list on scan tool. Using scan tool, monitor LOADS BATTERY FD parameter and DOORS BATTERY FD parameter. If both parameters are active, go to «DIAGNOSING INTERMITTENTS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) . If either parameter is not active, go to next step.
  3. Check battery feed circuit that did not display ACTIVE in previous step for an open. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams) . If open is not found, go to next step. If open is found, Repair as necessary and go to step 6 .
  4. Check for poor terminal contact at BCM harness connector. Repair as necessary and go to step 6 . If connection is okay, go to next step.
  5. Replace BCM. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under REMOVAL & INSTALLATION. Program BCM. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__body-control-module-programmingregular-production-option) under PROGRAMMING. After repair, go to next step.
  6. Turn ignition switch to OFF position. Reconnect any disconnected components and harness connectors. Using scan tool, clear DTCs. Operate vehicle within «CODE ENABLE CRITERIA»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) conditions. Using scan tool, retrieve DTCs. If DTC B1339 resets, return to step 2 . If DTC B1339 does not reset, system is okay.

Body Control Module (BCM) ground circuits provide ground for 2 theater dimming systems for interior lamps, Brake Transmission Shift Interlock (BTSI) solenoid, BCM electronics and door locks. DTC B1349 is set when BCM detects that any of its ground circuits are greater than 4 volts for longer than 30 seconds. When DTC B1349 is set, interior lamps do not function correctly. Brake-transmission safety interlock may not function correctly. Door lock features may not operate correctly and BCM stores DTC B1349 in memory. Current DTC B1349 will clear and become a history DTC when BCM no longer detects fault. History DTC B1349 will clear after 100 consecutive ignition cycles if problem for malfunction is no longer present.

Following criteria must be met to enable DTC; BCM electronics ground must be connected to ground.

  1. The BCM detects that any of its ground circuits are greater than 4 volts for longer than 300 milliseconds.
  1. The interior lamps do not function correctly.
  2. The brake-transmission safety interlock may not function correctly.
  3. The door lock features may not operate correctly.
  4. The BCM stores DTC B1349 in memory.
  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. Perform diagnostic system check for suspect system control module. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table under SELF-DIAGNOSTIC SYSTEM. Repair as necessary and go to step 6 . If diagnostic system check has been performed for suspect system control module, go to next step.
  2. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. Switch to BCM input data list on scan tool. Using scan tool, monitor THEATER DIM 1 GROUND, THEATER DIM 2 GROUND, DOORS SYSTEM GND, LOADS SYSTEM GND and ELECTRONIC SYSTEM GND. If all parameters are active, go to «DIAGNOSING INTERMITTENTS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) . If any parameter is not active, go to next step.
  3. Check ground circuit that did not display ACTIVE in previous step for an open. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams) . If open is not found, go to next step. If open is found, Repair as necessary and go to step 6 .
  4. Check for poor terminal contact at BCM harness connector. Repair as necessary and go to step 6 . If BCM harness connector terminal contact is okay, go to next step.
  5. Replace BCM. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under REMOVAL & INSTALLATION. Perform new BCM setup. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__body-control-module-programmingregular-production-option) under PROGRAMMING. After programming BCM, go to next step.
  6. Turn ignition switch to OFF position. Reconnect any disconnected components and harness connectors. Using scan tool, clear DTCs. Operate vehicle within «CODE ENABLE CRITERIA»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) conditions. Using scan tool, retrieve DTCs. If DTC B1349 resets, return to step 2 . If DTC B1349 does not reset, system is okay.

Body Control Module (BCM) monitors Ignition 0, Ignition 1 and accessory signals from ignition switch. BCM uses voltage state (battery voltage or 0) and sequence of state changes to determine power mode called for by ignition switch. DTC B1440 is set when one of ignition switch circuits is shorted to either battery voltage or ground. Sequence of change of circuit is incorrect for expected power mode.

When DTC B1440 is set, BCM stores DTC B1440 to memory. BCM operates in a fail-safe power mode dependent on last valid power mode detected and state of engine run flag data on class 2 serial data communications circuits. Other modules on vehicle operate in a fail safe power mode dependent on last valid power mode transmitted by BCM and state of engine run flag on class 2 serial data communications circuits.

Current DTC B1440 will clear and become a history DTC when BCM detects a sequence of ignition switch inputs that match expected power mode. History DTC will clear after 100 ignition cycles with no repeated malfunction.

Following criteria must be met to enable DTC; BCM must be powered and must detect a change in ignition switch circuit states.

  1. One of the ignition switch circuits may be shorted to either B+ or ground.
  2. The sequence of the change of the circuit is incorrect for the expected power mode.
  1. The BCM stores the DTC B1440 to memory.
  2. The BCM operates in a fail-safe power mode dependent on the last valid power mode detected and the state of the engine run flag data on the class 2 serial data communications circuits.
  3. The other modules on the vehicle operate in a fail safe power mode dependent on the last valid power mode transmitted by the BCM and the state of the engine run flag on the class 2 serial data communications circuits.
  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. Perform diagnostic system check for suspect system control module. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table under SELF-DIAGNOSTIC SYSTEM. Repair as necessary and go to step 15 . If diagnostic system check has been performed for suspect system control module, go to next step.
  2. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Switch to BCM data display inputs on scan tool. Using scan tool, monitor IGNITION 0, IGNITION 1 and ACCESSORY SWITCH. All parameters should be off or inactive. If all parameters are not as specified, go to next step. If any parameter is not as specified, go to step 7 .
  3. Turn ignition switch to ACCESSORY position. Ensure scan tool is in BCM data display inputs screen. Using scan tool, monitor IGNITION 0, IGNITION 1 and ACCESSORY SWITCH. IGNITION 0 and ACCESSORY SWITCH parameters should be active. If parameters are as specified, go to next step. If either parameter is not as specified, go to step 9 .
  4. Turn ignition switch to RUN position. Ensure scan tool is in BCM data display inputs screen. Using scan tool, monitor IGNITION 0, IGNITION 1 and ACCESSORY SWITCH. All parameters should be on or active. If all parameters are as specified, go to next step. If any parameter is not as specified, go to step 9 .
  5. Turn ignition switch to START position. Ensure scan tool is in BCM data display inputs screen. Using scan tool, monitor IGNITION 0, IGNITION 1 and ACCESSORY SWITCH. IGNITION 0 and IGNITION 1 parameters should be active. If parameters are as specified, go to next step. If either parameter is not as specified, go to step 9 .
  6. If any BCM data display inputs were not as specified in steps 2 - 5 , go to next step. If all BCM data display inputs were as specified, in steps 2 - 5 , go to step 12 .
  7. Turn ignition switch to OFF position. Disconnect ignition switch connectors. Ensure scan tool is in BCM data display inputs screen. Using scan tool, monitor IGNITION 0, IGNITION 1 and ACCESSORY SWITCH. If IGNITION 0, IGNITION 1 or ACCESSORY SWITCH parameter is active, go to next step. If IGNITION 0, IGNITION 1 and ACCESSORY SWITCH parameters are not active, go to step 10 .
  8. Disconnect BCM connectors. Check for short to power in suspect circuit (parameter indicated active). Repair as necessary and go to step 15 . If short to power is not found, go to step 12 .
  9. Turn ignition switch to OFF position. Disconnect ignition switch connectors. Connect a fused jumper wire (3-amp) between Black ignition switch harness connector terminal "A" (Red wire) and suspect circuit. Ensure scan tool is in BCM data display inputs screen. Using scan tool, monitor suspect circuit parameter (IGNITION 0, IGNITION 1 or ACCESSORY SWITCH). If suspect circuit is active, go to next step. If suspect circuit is still not active, go to step 11 .
  10. Check for poor terminal contact at ignition switch harness connector. Repair as necessary and go to step 15 . If ignition switch harness connector terminal contact is okay, go to step 13 .
  11. Disconnect BCM connectors. Check for short to ground or open in suspect circuit (parameter indicated not active). Repair as necessary and go to step 15 . If short to ground or open is not found, go to next step.
  12. Check for poor terminal contact at BCM harness connector. Repair as necessary and go to step 15 . If BCM harness connector terminal contact is okay, go to step 14 .
  13. Replace ignition switch and go to step 15 . See «IGNITION SWITCH»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under REMOVAL & INSTALLATION.
  14. Replace and reprogram BCM. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under REMOVAL & INSTALLATION. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__body-control-module-programmingregular-production-option) under PROGRAMMING. After repairs, go to next step.
  15. Turn ignition switch to OFF position. Reconnect any disconnected components and harness connectors. Using scan tool, clear DTCs. Operate vehicle within «CODE ENABLE CRITERIA»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) conditions. Using scan tool, retrieve DTCs. If DTC B1440 resets, return to step 2 . If DTC B1440 does not reset, system is okay.

Body Control Module (BCM) interfaces with vehicle's power distribution system through Retained Accessory Power (RAP) relay. RAP relay allows BCM to control application of power to feed circuits to sunroof and power windows. When ignition switch is in either ACC or RUN position, BCM energizes RAP relay by applying battery voltage to RAP relay control circuit.

BCM turns off RAP relay when ignition switch is in START position. RAP feature therefore disables during engine cranking. When ignition switch turns from RUN or ACC to LOCK or OFF, with all of vehicle doors closed, BCM leaves RAP relay energized for 10 minutes, or until any vehicle door opens and BCM detects a ground signal in one of door ajar circuits.

DTC B1477 is set when BCM detects no voltage at RAP relay control circuit when BCM is trying to energize RAP relay. Problem must be present for more than 30 seconds.

When DTC B1477 is set, BCM stores DTC B1477 in memory. RAP relay powered functions will not operate. Circuits powered by RAP relay will never be powered if relay control circuit is open.

Current DTC B1477 clears and becomes a history DTC when malfunction is no longer present. History DTC clears when module ignition cycle counter reaches reset threshold, without a repeat of malfunction.

Following criteria must be met to enable DTC; information is not available from manufacturer.

  1. The BCM detects no voltage at the RAP relay control circuit when the BCM is trying to energize the RAP relay.
  2. The above condition must be present for more than 300 milliseconds.
  1. The BCM stores DTC B1477 in memory.
  2. The RAP relay powered functions will not operate.
  3. The circuits powered by the RAP relay will never be powered if the relay control circuit is open.
  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. Perform Retained Accessory Power (RAP) system diagnostic system check. See «RETAINED ACCESSORY POWER (RAP) SYSTEM DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__retained-accessory-power-system-diagnostic-system) under SELF-DIAGNOSTIC SYSTEM. If Retained Accessory Power (RAP) system diagnostic system check has been performed, go to next step.
  2. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. Using scan tool, command RAP relay ON and OFF. If RAP relay does not operate as commanded, go to next step. If RAP relay operates as commanded, check for intermittent problem. See «DIAGNOSING INTERMITTENTS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules). Repair or replace as necessary and go to step 13.
  3. Turn ignition switch to OFF position. Remove RAP relay from left instrument panel fuse block. Turn ignition switch to RUN position. Connect a test light between ground and RAP relay connector terminal No. 707 in left instrument panel fuse block. (Scheme 9) Using scan tool, command RAP relay ON and OFF. If test light turns on and off as commanded, go to next step. If test light does not turn on and off as commanded, go to step 5.
  4. Connect a test light between RAP relay connector terminals No. 707 and No. 1050 in left instrument panel fuse block. (Scheme 9) Using scan tool, command RAP relay ON and OFF. If test light turns on and off as commanded, go to step 8. If test light does not turn ON and OFF as commanded, go to step 10.
  5. If test light remains illuminated with both commands, go to step 7. If test light does not remain illuminated with both commands, go to next step.
  6. Check short to ground in circuit between RAP relay connector terminal No. 707 in left instrument panel fuse block and BCM Gray, 24-pin harness connector C2 terminal B9 (Black wire). See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and go to step 13. If circuit is okay, go to step 9.
  7. Check for short to power in circuit between RAP relay connector terminal No. 707 in left instrument panel fuse block and BCM Gray, 24-pin harness connector C2 terminal B9 (Black wire). See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and go to step 13. If circuit is okay, go to step 9.
  8. Check for poor connection at RAP relay connector. Repair as necessary and go to step 13. If connection is okay, go to step 11.
  9. Check for poor connection at BCM Gray, 24-pin connector C2. Repair as necessary and go to step 13. If connection is okay, go to step 12.
  10. Repair open or high resistance in circuit between RAP relay connector terminal No. 1050 in left instrument panel fuse block and ground connector G201. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and go to step 13.
  11. Replace RAP relay and go to step 13.
  12. Replace and program BCM. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under REMOVAL & INSTALLATION. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__body-control-module-programmingregular-production-option) under PROGRAMMING. After repair, go to next step.
  13. Using scan tool, clear DTCs. Operate vehicle within «CODE ENABLE CRITERIA»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) conditions. Using scan tool, retrieve DTCs. If DTC B1477 resets, return to step 2. If DTC B1477 does not reset, system is okay.

Scheme 9

Scheme 9
Scheme 9

Body Control Module (BCM) interfaces with vehicle's power distribution system through Retained Accessory Power (RAP) relay. RAP relay allows BCM to control application of power to feed circuits to sunroof and power windows. When ignition switch is in either ACC or RUN position, BCM energizes RAP relay by applying battery voltage to control circuit.

BCM turns off RAP relay when ignition switch is in START position. RAP feature therefore disables during engine cranking. When ignition switch turns from RUN or ACC to LOCK or OFF, with all of vehicle doors closed, BCM leaves RAP relay energized for 10 minutes, or until any vehicle door opens and BCM detects a ground signal in one of door ajar circuits.

DTC B1478 is set when BCM detects a short to battery in RAP relay control circuit when BCM is trying to de-energize RAP relay. Problem above must be present for more than 30 seconds.

When DTC B1478 is set, circuits powered by RAP relay remain powered at all times if RAP relay control circuit is shorted to battery voltage. BCM stores DTC B1478 in memory.

Current DTC B1478 clears and becomes a history DTC when malfunction is no longer present. History DTC B1478 clears when module ignition cycle counter reaches reset threshold, without a repeat of malfunction.

Following criteria must be met to enable DTC; BCM must be commanding RAP relay to energize.

  1. The BCM detects a short to battery in the RAP relay control circuit when the BCM is trying to de-energize the RAP relay.
  2. The condition above must be present for more than 300 milliseconds.
  1. The circuits powered by the RAP relay remain powered at all times if the RAP relay control circuit is shorted to battery voltage.
  2. The BCM stores DTC B1478 in memory.
  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.

Scheme 10

Scheme 10: Testing
Scheme 10: Testing
  1. Perform Retained Accessory Power (RAP) system diagnostic system check. See «RETAINED ACCESSORY POWER (RAP) SYSTEM DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__retained-accessory-power-system-diagnostic-system) under SELF-DIAGNOSTIC SYSTEM. If Retained Accessory Power (RAP) system diagnostic system check has been performed, go to next step.
  2. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. Using scan tool, command RAP relay ON and OFF. If RAP relay does not operate as commanded, go to next step. If RAP relay operates as commanded, check for intermittent problem. See «DIAGNOSING INTERMITTENTS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules). Repair or replace as necessary and go to step 13.
  3. Turn ignition switch to OFF position. Remove RAP relay from left instrument panel fuse block. Turn ignition switch to RUN position. Connect a test light between ground and RAP relay connector terminal No. 707 in left instrument panel fuse block. (Scheme 9) Using scan tool, command RAP relay ON and OFF. If test light turns on and off as commanded, go to next step. If test light does not turn on and off as commanded, go to step 5.
  4. Connect a test light between RAP relay connector terminals No. 707 and No. 1050 in left instrument panel fuse block. (Scheme 9) Using scan tool, command RAP relay ON and OFF. If test light turns on and off as commanded, go to step 8. If test light does not turn on and off as commanded, go to step 10.
  5. If test light remains illuminated with both commands, go to step 7. If test light does not remain illuminated with both commands, go to next step.
  6. Check for open in circuit between RAP relay connector terminal No. 707 in left instrument panel fuse block and BCM Gray, 24-pin harness connector C2 terminal B9 (Black wire). See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and go to step 13. If circuit is okay, go to step 9.
  7. Check for short to power in circuit between RAP relay connector terminal No. 707 in left instrument panel fuse block and BCM Gray, 24-pin harness connector C2 terminal B9 (Black wire). See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and go to step 13. If circuit is okay, go to step 9.
  8. Check for poor connection at RAP relay connector. Repair as necessary and go to step 13. If connection is okay, go to step 11.
  9. Check for poor connection at BCM Gray, 24-pin connector C2. Repair as necessary and go to step 13. If connection is okay, go to step 12.
  10. Repair open or high resistance in circuit between RAP relay connector terminal No. 1050 in left instrument panel fuse block and ground connector G201. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and go to step 13.
  11. Replace RAP relay and go to step 13.
  12. Replace and program BCM. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under REMOVAL & INSTALLATION. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__body-control-module-programmingregular-production-option) under PROGRAMMING. After repair, go to next step.
  13. Using scan tool, clear DTCs. Operate vehicle within «CODE ENABLE CRITERIA»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) conditions. Using scan tool, retrieve DTCs. If DTC B1478 resets, return to step 2. If DTC B1478 does not reset, system is okay.

Modules connected to class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among modules. When a module receives a message for a critical operating parameter, module records identification number of module which sent message for State of Health monitoring. A critical operating parameter is one which, when not received, requires that module use a default value for that parameter. When a module does not associate an identification number with at least 1 critical parameter within about 5 seconds of beginning serial data communication, DTC U1000 or U1255 is set. When more than one critical parameter does not have an identification number associated with it, DTC will only be reported once.

DTC U1000 or U1255 is set when, at least one critical operating parameter has not been associated with an identification number within about 5 seconds after beginning serial data communication. When U1000 or U1255 is set, module uses a default value for missing parameter.

Current DTC U1000 or U1255 clears and becomes a history DTC when malfunction is no longer present. History DTC U1000 or U1255 clears when module ignition cycle counter reaches reset threshold, without a repeat of malfunction.

Following criteria must be met to enable DTC

  1. Voltage supplied to module must be 9-16 volts.
  2. DTCs U1300, U1301 and U1305 must not be current.
  3. Ignition switch position requires serial data communication to occur.
  1. At least one critical operating parameter has not been associated with an identification number within about 5 seconds after beginning serial data communication.
  1. The module uses a default value for the missing parameter.
  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. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Start engine and wait at least 5 seconds. Using scan tool, retrieve DTCs. If history DTCs in range of U1001-U1254 are not set, go to next step. If history DTCs in range of U1001-U1254 are set, go to «DTC U1001-U1254: LOSS OF XXX COMMUNICATIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules).
  2. Turn engine off. Turn ignition switch to RUN position. Using CLASS 2 MESSAGE MONITOR of scan tool, try to establish scan tool communication with each module on class 2 serial data link. Record all modules communicating on class 2 serial data link. Compare list of modules communicating with scan tool to list of modules connected on class 2 serial data link. See appropriate DATA LINK CONNECTORS wiring diagram in WIRING DIAGRAMS. If any modules are not communicating, go to next step. If all modules are communicating, go to step 13.
  3. Test battery feed and ignition feed circuits for module(s) not communicating on class 2 serial data link for opens or shorts to ground. See appropriate POWER DISTRIBUTION wiring diagram in WIRING DIAGRAMS. If no opens or shorts to ground are found, go to next step. If opens or shorts to ground are found, repair as necessary and go to step 9.
  4. Turn ignition switch to OFF position. Test ground circuit for module(s) not communicating on class 2 serial data link for opens. See appropriate GROUND DISTRIBUTION wiring diagram in WIRING DIAGRAMS. If no opens are found, go to next step. If opens are found, repair as necessary and go to step 9.
  5. Disconnect splice pack SP205 connector. Splice pack SP205 connector is located behind DLC. (Scheme 11) Check splice pack SP205 connector for poor connection. If poor connection is not found, go to next step. If poor connection is found, repair as necessary and go to step 9.
  6. Test class 2 serial data link for module(s) not communicating on class 2 serial data link for opens. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). If no opens are found, go to next step. If opens are found, repair as necessary and go to step 9.
  7. Check for poor connections at battery feed, ignition feed, ground and class 2 serial data link at connectors for module(s) not communicating on class 2 serial data link. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). If no poor connections are found, go to next step. If poor connections are found, repair as necessary and go to step 9.
  8. Replace module(s) not communicating on class 2 serial data link. See appropriate removal and installation procedure under «REMOVAL & INSTALLATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__removal-installation). After repair, go to step 11.
  9. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. Using scan tool, select DISPLAY DTC function for module(s) not communicating on class 2 serial data link. If scan tool displays any DTC beginning with "U", go to next step. If scan tool displays any DTC not beginning with a "U", perform diagnostic system check for applicable system. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) under SELF-DIAGNOSTIC SYSTEM. Repair as necessary.
  10. Using scan tool, clear DTCs. After clearing DTCs, go to next step.
  11. Using scan tool, select DISPLAY DTC function for module(s) that had DTC U1000 set as current. If scan tool displays any DTC beginning with "U", go to next step. If scan tool displays DTCs not beginning with a "U", perform appropriate diagnostic system check for applicable system. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) under SELF-DIAGNOSTIC SYSTEM. Repair as necessary.
  12. Using scan tool, clear DTCs. After clearing DTCs, system is okay.
  13. If no other DTCs are recorded for module(s) that set DTC U1000, go to next step. If any other DTCs are recorded for module(s) that set DTC U1000, perform diagnostic system check for applicable system. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) under SELF-DIAGNOSTIC SYSTEM. Repair as necessary.
  14. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. Using scan tool, clear DTCs. Turn ignition switch to OFF position for at least 5 seconds. Turn ignition switch to RUN position. Using scan tool, select DISPLAY DTC function. If scan tool displays DTC U1000 or DTC U1255 as current, go to next step. If scan tool does not display DTC U1000 or DTC U1255 as a current, go to «DIAGNOSTIC AIDS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules).
  15. Replace module(s) that had DTC U1000 set as a current DTC. See appropriate removal and installation procedure under «REMOVAL & INSTALLATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__removal-installation). After repair, system is okay.

Scheme 11

Scheme 11
Scheme 11

When a malfunction such as an open fuse to a module occurs while modules are communicating, a lost communication DTC is set as a current DTC. When modules stop communicating (ignition is turned OFF) current lost communication DTC is cleared but history DTC remains. When modules begin to communicate again, module with open fuse will not be learned by other modules so DTC U1000 or U1255 is set current by other modules. If malfunction occurs when modules are not communicating, only DTC U1000 or U1255 is set.

Modules connected to class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among modules. When a module receives a message for a critical operating parameter, module records identification number of module which sent message for state of health messages monitoring. A critical operating parameter is one which, when not received, requires that module use a default value for that parameter. Once an identification number is learned by a module, it will monitor for that module's state of health message. Each module on class 2 serial data circuit which is powered and performing functions that require detection of a communications malfunction is required to send a state of health message every 2 seconds. When no message is detected from a learned identification number for 5 seconds, a DTC U1xxx, where xxx is equal to 3 digit identification number, is set.

Control module ID number list provides a method for determining which module is not communicating. A module with an internal class 2 serial data circuit malfunction or which loses power during current ignition cycle would have a lost communication DTC set by other modules. Modules that can communicate will set a DTC indicating module that cannot communicate. When no message is detected from a learned identification number for five seconds, a DTC U1xxx, where xxx is equal to 3 digit identification number, is set. See MODULE DTC IDENTIFICATION table.

Module ID NumberModule Not Communicating
016Powertrain Control Module
040Electronic Brake Control Module/Electronic Brake Traction Control Module
064Body Control Module
088Inflatable Restraint Sensing & Diagnostic Module
096Instrument Panel Cluster
128Radio

MODULE DTC IDENTIFICATION

If more than one loss of communication DTC is set in either one or multiple modules, perform diagnosis in following order

  1. Current DTCs before history DTCs, unless otherwise instructed in testing procedure.
  2. DTC which is reported most times.
  3. From lowest number DTC to highest number DTC.

DTC U1001-U1254 is set when, a message from a learned identification number has not been detected for past 5 seconds. Current DTCs U1001-U1254 will clear and become history DTCs when malfunction is no longer present. History DTCs U1001-U1254 will clear when module ignition cycle counter reaches reset threshold, without a repeat of malfunction.

Following criteria must be met to enable DTC

  1. Voltage supplied to module is in normal operating voltage range of 9 to 16 volts.
  2. Diagnostic trouble codes U1300, U1301 and U1305 do not have a current status.
  3. Vehicle power mode, ignition switch position, requires serial data communication to occur.
  1. A message from a learned identification number has not been detected for the past 5 seconds.
  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. Test battery feed and ignition feed circuits for module(s) not communicating on class 2 serial data link for opens or shorts to ground. See appropriate POWER DISTRIBUTION wiring diagram in WIRING DIAGRAMS. If open or short to ground is found, go to next step. If open or short to ground is found, repair as necessary and go to step 9.
  2. Turn ignition switch to OFF position. Test ground circuit for module(s) not communicating on class 2 serial data link for opens. See appropriate GROUND DISTRIBUTION wiring diagram in WIRING DIAGRAMS. If no open is found, go to next step. If open is found, repair as necessary and go to step 9.
  3. Disconnect splice pack SP205 connectors. Splice pack SP205 is located behind DLC. (Scheme 11) Check splice pack SP205 connectors for poor connections. If no poor connections are found, go to next step. If poor connections are found, repair as necessary and go to step 7.
  4. Test class 2 serial data link for module(s) not communicating on class 2 serial data link for opens. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). If no opens are found, go to next step. If opens are found, repair as necessary and go to step 7.
  5. Check for poor connections at battery feed, ignition feed, ground and class 2 serial data link at connectors for module(s) not communicating on class 2 serial data link. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). If no poor connections are found, go to next step. If poor connections are found, repair as necessary and go to step 7.
  6. Replace module(s) not communicating on class 2 serial data link. See appropriate procedure under «REMOVAL & INSTALLATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__removal-installation). After repair, go to step 9.
  7. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. Using scan tool, select DISPLAY DTC function for module(s) not communicating on class 2 serial data link. If scan tool displays any DTC beginning with "U", go to next step. If scan tool displays any DTC not beginning with a "U", perform diagnostic system check for applicable system. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) under SELF-DIAGNOSTIC SYSTEM. Repair as necessary.
  8. Using scan tool, clear DTCs. After clearing DTCs, go to next step.
  9. Using scan tool, select DISPLAY DTC function for module(s) that had DTC U1000 set as current. If scan tool displays any DTC beginning with "U", go to next step. If scan tool displays DTCs not beginning with a "U", perform diagnostic system check for applicable system. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__diagnostic-trouble-code-definitions) under SELF-DIAGNOSTIC SYSTEM. Repair as necessary.
  10. Using scan tool, clear DTCs. Continue diagnosing and/or clearing DTCs until all modules have been diagnosed and/or all DTCs are cleared. After repair, system is okay.

Modules connected to class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among modules. In addition to this, state of health messages are transmitted by each module on class 2 serial data circuit about once every 2 seconds. When a module detects no serial data messages and a low voltage on class 2 serial data circuit for about 3 seconds, U1300 is set. Setting of all other class 2 serial communication DTCs is inhibited.

DTC U1300 is set when, no valid messages are detected on class 2 serial data circuit. Voltage level detected on class 2 serial data circuit is low. Conditions are met for about 3 seconds.

When DTC U1300 is set, module inhibits setting of all other class 2 DTCs. Module uses default values for all parameters received on class 2 serial data circuit.

Current DTC U1300 will clear and become a history DTC when a valid class 2 message is detected on class 2 serial data circuit or at end of current ignition cycle. History DTC U1300 will clear after 100 ignition on/off cycles with no repeat of malfunction.

Following criteria must be met to enable DTC

  1. Voltage supplied to module is in normal operating voltage range of 9 to 16 volts.
  2. Vehicle power mode, ignition switch position, requires serial data communication to occur.

DTC U1300 indicates a short to ground or power in class 2 serial data line to a particular module. DTC U1300 will only be read as a history DTC. Check for intermittent connections and circuits by wiggling wires and connectors to suspect modules. See TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS to isolate intermittent condition.

Modules connected to class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among modules. In addition to this, state of health messages are transmitted by each module on class 2 serial data circuit about once every 2 seconds. When module detects no messages and a high voltage on class 2 serial data circuit for approximately 3 seconds, U1301 is set. Setting of all other class 2 serial communication DTCs is inhibited.

DTC U1301 is set when no valid messages are detected on class 2 serial data circuit. Voltage level detected on class 2 serial data circuit is high. Conditions are met for approximately 3 seconds.

When DTC U1301 is set module inhibits setting of all other class 2 DTCs. Module uses default values for all parameters received on class 2 serial data circuit.

Current DTC U1301 will clear and become a history DTC when a valid class 2 message is detected on class 2 serial data circuit or at end of current ignition cycle. History DTC U1301 will clear after 100 ignition on/off cycles with no repeated malfunction.

Following criteria must be met to enable DTC

  1. Voltage supplied to module is in normal operating voltage range of 9 to 16 volts.
  2. Vehicle power mode, ignition switch position, requires serial data communication to occur.
  1. No valid messages are detected on the class 2 serial data circuit.
  2. The voltage level detected on the class 2 serial data circuit is under one of the following conditions: Always high Always low
  3. The above conditions are met for approximately 3 seconds.
  1. The module inhibits the setting of all other class 2 DTCs.
  2. The module uses default values for all parameters received on the class 2 serial data circuit.
  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 U1301 indicates a short to ground or power in class 2 serial data line to a particular module. DTC U1301 will only be read as a history DTC. Check for intermittent connections and circuits by wiggling wires and connectors to suspect modules. See TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS to isolate intermittent condition.

Modules connected to class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among modules. In addition to this, state of health messages are transmitted by each module on class 2 serial data circuit about once every 2 seconds. When a module detects no messages on class 2 serial data circuit for approximately 3 seconds, with no low or high voltage detected, U1305 is set. Setting of all other class 2 serial communication DTCs is inhibited.

DTC U1305 is set when, no valid class 2 messages are detected on class 2 serial data circuit. Problem is met for approximately 3 seconds.

When DTC U1305 is set, module inhibits setting of all other class 2 DTCs. Module uses default values for all parameters received on class 2 serial data circuit.

Current DTC U1305 will clear and become a history DTC when a valid class 2 message is detected on class 2 serial data circuit or at end of current ignition cycle. History DTC U1305 will clear after 100 ignition on/off cycles with no repeated malfunction.

Following criteria must be met to enable DTC

  1. Voltage supplied to module is in normal operating voltage range of 9 to 16 volts.
  2. Vehicle power mode, ignition switch position, requires serial data communication to occur.
  1. No valid messages are detected on the class 2 serial data circuit.
  2. The voltage level detected on the class 2 serial data circuit is under one of the following conditions: Always high Always low
  3. The above conditions are met for approximately 3 seconds.
  1. The module inhibits the setting of all other class 2 DTCs.
  2. The module uses default values for all parameters received on the class 2 serial data circuit.
  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 U1305 indicates a short to ground or power in class 2 serial data line to a particular module. DTC U1305 will only be read as a history DTC. Check for intermittent connections and circuits by wiggling wires and connectors to suspect modules. See TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS to isolate intermittent condition.

SYSTEM TESTS

CAUTIONElectronic modules are sensitive to static electrical charges. Proper grounding of technician and workplace is essential to prevent damage.

Note. DO NOT replace Body Control Module (BCM) unless a DTC remains current after all DTC repairs have been performed. DO NOT replace BCM if only history DTCs are set.

Note. Always check module ground and power circuits prior to replacing a control module. See GROUND DISTRIBUTION and/or POWER DISTRIBUTION articles in WIRING DIAGRAMS.

SymptomPerform System Test
Retained Accessory Power InoperativeA
Retained Accessory Power On After Time-OutB
Scan Tool Does Not Communicate With Class 2 DeviceC
Scan Tool Does Not Power UpD
Power Mode MismatchE

SYMPTOM INDEX

TEST A: RETAINED ACCESSORY POWER INOPERATIVE

  1. Perform Retained Accessory Power (RAP) system diagnostic system check. See «RETAINED ACCESSORY POWER (RAP) SYSTEM DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__retained-accessory-power-system-diagnostic-system) under SELF-DIAGNOSTIC SYSTEM. If Retained Accessory Power (RAP) system diagnostic system check has been performed, go to next step.
  2. Close all doors. Turn ignition switch to RUN position and back to OFF position. Operate power windows and sun roof (if equipped). If power windows and sun roof (if equipped) operate properly, check for intermittent problem. See «DIAGNOSING INTERMITTENTS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules). Repair or replace as necessary and go to step 10. If power windows and sun roof (if equipped) doe not operate properly, go to next step.
  3. Remove RAP relay from left instrument panel fuse block. Connect a test light between RAP relay connector terminals No. 707 and No. 1050 in left instrument panel fuse block. (Scheme 9) Ensure all doors are closed. Turn ignition switch to RUN position and back to OFF position. If test light illuminates, go to step 6. If test light does not illuminate, go to next step.
  4. Check open in circuit between RAP relay connector terminal No. 707 in left instrument panel fuse block and BCM Gray, 24-pin harness connector C2 terminal B9 (Black wire). Also, check for open in circuit between RAP relay connector terminal No. 1050 in left instrument panel fuse block and ground connector G201. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and go to step 10. If circuit is okay, go to step 7.
  5. Check short to power in circuit between RAP relay connector terminal No. 707 in left instrument panel fuse block and BCM Gray, 24-pin harness connector C2 terminal B9 (Black wire). See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and go to step 10. If circuit is okay, go to step 9.
  6. Check for poor connection at RAP relay connector. Repair as necessary and go to step 10. If connection is okay, go to step 8.
  7. Check for poor connection at BCM Gray, 24-pin connector C2. Repair as necessary and go to step 10. If connection is okay, go to step 9.
  8. Replace RAP relay and go to step 10.
  9. Replace and reprogram BCM. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under REMOVAL & INSTALLATION. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__body-control-module-programmingregular-production-option) under PROGRAMMING. After repairs, go to next step.
  10. Check system operation. If system operates properly, system okay at this time. If system does not operate properly, go to step 3.

TEST B: RETAINED ACCESSORY POWER ON AFTER TIME-OUT

  1. Perform Retained Accessory Power (RAP) system diagnostic system check. See «RETAINED ACCESSORY POWER (RAP) SYSTEM DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__retained-accessory-power-system-diagnostic-system) under SELF-DIAGNOSTIC SYSTEM. If Retained Accessory Power (RAP) system diagnostic system check has been performed, go to next step.
  2. Turn ignition switch to LOCK position. Remove RAP relay from left instrument panel fuse block. Operate power windows and sun roof (if equipped). If power windows and sun roof (if equipped) operate properly, go to next step. If power windows and sun roof (if equipped) doe not operate properly, go to step 4.
  3. Check for short to power in circuit between RAP relay connector in left instrument panel fuse block and suspect component. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and go to step 7.
  4. Connect a test light between ground and RAP relay connector terminal No. 707 in left instrument panel fuse block. (Scheme 9) If test light illuminates, go to step 6. If test light does not illuminate, go to next step.
  5. Replace RAP relay and go to step 7.
  6. Replace and reprogram BCM. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) under REMOVAL & INSTALLATION. See «BODY CONTROL MODULE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__body-control-module-programmingregular-production-option) under PROGRAMMING. After repairs, go to next step.
  7. Check system operation. If system operates properly, system okay at this time. If system does not operate properly, go to step 2.
  1. Connect scan tool to Data Link Connector (DLC). If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST D: SCAN TOOL DOES NOT POWER UP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__test-d-scan-tool-does-not) under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Attempt to communicate with Auxiliary Power Drop Connector, BCM, Drive Information center (DIC), Electronic Brake Control Module (EBCM), Instrument Panel Cluster (IPC), Powertrain Control Module (PCM), Radio, Remote CD player (if equipped with performance-enhanced audio), inflatable restraint Sensing and Diagnostic Module (SDM) and Vehicle Interface Unit (VIU), if equipped. If scan tool communicates with any module, go to next step. If scan tool does not communicate with any module, go to step 5.
  3. Using scan tool, select DISPLAY DTCs function for each module. Record each DTC and DTC status. Also record which module set DTCs. If any DTC between U1000-U1255 are present, go to next step. If no DTCs between U1000-U1255 are present, see «DIAGNOSTIC AIDS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules).
  4. If DTC U1000 or U1255 are only DTCs displayed in step 3, go to appropriate DTC for testing. Repair as necessary. If DTC U1000 or U1255 are not displayed in step 3, check for DTC U1001-U1254. Repair as necessary.
  5. Turn ignition switch to OFF position. Disconnect scan tool from DLC. Inspect DLC connector terminals No. 2 (Purple wire) and 5 (Black/White wire) for poor terminal contact. (Scheme 19) Repair as necessary and preform appropriate diagnostic system check for suspect system. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table. If connection is okay, go to next step.
  6. Check for open or high resistance in Black/White wire between ground connector G203 and DLC terminal No. 5. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and preform appropriate diagnostic system check for suspect system. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table. If wire is okay, go to next step.
  7. Disconnect splice pack SP205. (Scheme 11) Check for poor terminal contact at splice pack SP205 connector. Repair as necessary and preform appropriate diagnostic system check for suspect system. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table. If connection is okay, go to next step.
  8. Check for open or high resistance in Purple wire between DLC terminal No. 2 and splice pack SP205 terminal "A". (Scheme 19)and (Scheme 14). See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). Repair as necessary and preform appropriate diagnostic system check for suspect system. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table. If wire is okay, go to next step.
  9. Connect a fused jumper wire between splice pack SP205 harness connector terminals "A" (Purple wire) and terminal "M" (Light Green wire). Turn ignition switch to RUN position. Using scan tool, attempt communication with BCM. If scan tool does not communicate with BCM, go to next step. If scan tool communicates with BCM, go to step 11.
  10. Disconnect fused jumper wire. Turn ignition switch to OFF position. Disconnect BCM Pink, 24-pin connector C1. (Scheme 20) Check for short or open in Light Green wire between splice pack SP205 harness connector terminal "M" and BCM Pink, 24-pin harness connector C1 terminal A5. (Scheme 14) See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and go to step 29. If wire is okay, go to step 27.
  11. With first fused jumper wire still connected, connected a second jumper wire between splice pack SP205 harness connector terminals "A" (Purple wire) and terminal "B" (Dark Green wire). Turn ignition switch to RUN position. Using scan tool, attempt communication with Powertrain Control Module (PCM). If scan tool does not communicate with BCM, go to next step. If scan tool communicates with PCM, go to step 13.
  12. Turn ignition switch to OFF position. Disconnect PCM Blue, 80-pin connector C1. (Scheme 15) Check for short to ground or power in Dark Green wire between splice pack SP205 harness connector terminal "B" and PCM Blue, 80-pin harness connector C1 terminal No. 59. (Scheme 15) See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and go to 29. If wire is okay, go to step 27.
  13. Disconnect one end of fused jumper wire from splice pack SP205 harness connector terminal "B" (Dark Green wire) and connect that end of fused jumper wire to splice pack SP205 harness connector terminal "C" (Purple wire). (Scheme 14) Turn ignition switch to RUN position. Using scan tool, attempt communication with auxiliary power drop connector and Vehicle Interface Unit (VID), is equipped. If scan tool does not communicate with auxiliary power drop connector or VID, go to next step. If scan tool communicates with auxiliary power drop connector and VID, go to step 15.
  14. Turn ignition switch to OFF position. Disconnect auxiliary power drop connector and VID Red, 32-pin connector C1. (Scheme 12) Check for short to ground or power in Purple wire between splice pack SP205 harness connector terminal "C" and auxiliary power drop connector harness connector terminal "D" or VID Red, 32-pin harness connector C1 terminal A2. (Scheme 13) See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and go to step 29. If wire is okay, go to step 27.
  15. Disconnect one end of fused jumper wire from splice pack SP205 harness connector terminal "C" (Purple wire) and connect that end of fused jumper wire to splice pack SP205 harness connector terminal "D" (Orange wire). (Scheme 14) Turn ignition switch to RUN position. Using scan tool, attempt communication with radio. If scan tool does not communicate with radio, go to next step. If scan tool communicates with radio, go to step 17.
  16. Turn ignition switch to OFF position. Disconnect radio Gray, 24-pin connector C1. Check for short to ground or power in Orange wire between splice pack SP205 harness connector terminal "D" and radio Gray, 24-pin harness connector C1 terminal A1. (Scheme 14) See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and go to step 29. If wire is okay, go to step 27.
  17. Disconnect one end of fused jumper wire from splice pack SP205 harness connector terminal "D" (Orange wire) and connect that end of fused jumper wire to splice pack SP205 harness connector terminal "E" (Light Blue wire). (Scheme 14) Turn ignition switch to RUN position. Using scan tool, attempt communication with Electronic Brake Traction Control Module (EBCM). If scan tool does not communicate with EBCM, go to next step. If scan tool communicates with EBCM, go to step 19.
  18. Turn ignition switch to OFF position. Disconnect EBCM connector. Check for short to ground or power in Light Blue wire between splice pack SP205 harness connector terminal "E" and EBCM harness connector terminal B7. (Scheme 14) See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and go to step 29. If wire is okay, go to step 27.
  19. Disconnect one end of fused jumper wire from splice pack SP205 harness connector terminal "E" (Light Blue wire) and connect that end of fused jumper wire to splice pack SP205 harness connector terminal "F" (Dark Blue wire). Turn ignition switch to RUN position. Using scan tool, attempt communication with inflatable restraint Sensing and Diagnostic Module (SDM). If scan tool does not communicate with SDM, go to next step. If scan tool communicates with SDM, go to step 21.
  20. Turn ignition switch to OFF position. Disconnect SDM connector. Check for short to ground or power in Dark Blue wire between splice pack SP205 harness connector terminal "F" and SDM harness connector terminal A5. (Scheme 14) See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and go to step 29. If wire is okay, go to step 27.
  21. Disconnect one end of fused jumper wire from splice pack SP205 harness connector terminal "F" (Dark Blue wire) and connect that end of fused jumper wire to splice pack SP205 harness connector terminal "G" (Gray wire). Turn ignition switch to RUN position. Using scan tool, attempt communication with Instrument Panel Cluster (IPC). If scan tool does not communicate with IPC, go to next step. If scan tool communicates with IPC, go to step 21.
  22. Turn ignition switch to OFF position. Disconnect IPC connector. Check for short to ground or power in Gray wire between splice pack SP205 harness connector terminal "G" and IPC harness connector terminal A7. (Scheme 14) See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and go to step 29. If wire is okay, go to step 27.
  23. If not equipped with remote CD player (if equipped with performance-enhanced audio), go to 25. If equipped with remote CD player (if equipped with performance-enhanced audio), disconnect one end of fused jumper wire from splice pack SP205 harness connector terminal "G" (Gray wire) and connect that end of fused jumper wire to splice pack SP205 harness connector terminal "H" (Gray wire). (Scheme 14) Turn ignition switch to RUN position. Using scan tool, attempt communication with remote CD player (if equipped with performance-enhanced audio). If scan tool communicates with remote CD player (if equipped with performance-enhanced audio), go to step 25. If scan tool does not communicate with remote CD player (if equipped with performance-enhanced audio), go to next step.
  24. Turn ignition switch to OFF position. Disconnect remote CD player (if equipped with performance-enhanced audio) connector. Check for short to ground or power in Gray wire between splice pack SP205 harness connector terminal "H" and remote CD player (if equipped with performance-enhanced audio) harness connector terminal No. 10. (Scheme 14) See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and go to step 29. If circuit is okay, go to step 27.
  25. If equipped with remote CD player (if equipped with performance-enhanced audio), disconnect jumper wire from splice pack SP205 connector terminal "H" (Gray wire) and connect that end of fused jumper wire to splice pack SP205 harness connector terminal "K" (Yellow wire). If not equipped with remote CD player (if equipped with performance-enhanced audio), disconnect jumper wire from splice pack SP205 connector terminal "G" (Gray wire) and connect that end of fused jumper wire to splice pack SP205 harness connector terminal "K" (Yellow wire). Turn ignition switch to RUN position. Using scan tool, attempt to communicate with Driver Information Center (DIC). If scan tool communicates with DIC, go to step 29. If scan tool does not communicate with DIC, go to next step.
  26. Turn ignition switch to OFF position. Disconnect DIC connector. Check for short to ground or power in Yellow wire between splice pack SP205 harness connector terminal "K" and DIC harness connector terminal No. 15. (Scheme 14) See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and go to step 29. If circuit is okay, go to step 27.
  27. Check for poor terminal contact at suspect module. Repair as necessary and go to step 29. See «WIRING DIAGRAMS»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__wiring-diagrams). If connection is okay, go to next step.
  28. Replace suspect module and go to next step.
  29. Reconnect all disconnected connectors. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. Wait 10 seconds. Select DISPLAY DTCs function for each module. Record any communication DTCs (DTCs beginning with a "U"). If no communication DTCs are present, go to next step. If any communication DTCs are present, and they have current status, go to step 31.
  30. If any non communication DTCs (do not begin with a "U") were recorded, go to next step. If no non communication DTCs (do not begin with a "U") were recorded, go to step 33.
  31. If any DTCs are present, go to appropriate system starting point for related system. Repair appropriate system as necessary and go to next step.
  32. If no DTCs are present, go to next step. If any DTCs are present, go to step 31.
  33. Using scan tool, clear DTCs. Operate vehicle within conditions for running DTC. If DTC does not reset, test is complete.

Scheme 12

Scheme 12
Scheme 12

Scheme 13

Scheme 13
Scheme 13

Scheme 14

Scheme 14
Scheme 14

Scheme 15

Scheme 15
Scheme 15

Scheme 16

Scheme 16
Scheme 16

Scheme 17

Scheme 17
Scheme 17

Scheme 18

Scheme 18
Scheme 18

BCM detects that ignition is on and send appropriate power mode message to other modules. BCM must be connected to DLC for any other module to communicate with scan tool. When class 2 serial data circuit is shorted to ground, DTC U1300 or U1305 will be set. If DTC U1300 or U1305 is present, go to DTC U1300: CLASS 2 DATA LINK SHORTED TO GROUND . When class 2 serial data circuit is shorted to power, DTC U1301 or U1305 will be set. If DTC U1301 or U1305 is present, go to DTC U1301: CLASS 2 DATA LINK SHORTED TO POWER .

TEST D: SCAN TOOL DOES NOT POWER UP

  1. Check for a blown CLSTER/BCM fuse (10-amp) located in fuse block located at left side of instrument panel. If fuse is okay, check for short to ground or open in Orange wire between DLC connector terminal No. 16 and CLSTER/BCM fuse (10-amp). See appropriate wiring diagram in DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and preform appropriate diagnostic system check for suspect system. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table. If fuse and wire are okay, go to next step.
  2. Check for open or high resistance in Black wire between ground and DLC terminal No. 4. (Scheme 19) Repair as necessary and preform appropriate diagnostic system check for suspect system. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table. If wire is okay, go to next step.
  3. Check for poor terminal contact at DLC connector terminals No. 4 (Black wire) and No. 16 (Orange wire). Repair as necessary and preform appropriate diagnostic system check for suspect system. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table. If connection is okay, go to next step.
  4. Connect scan tool to another vehicle. If scan tool operates on another vehicle, check for poor connection between scan tool and DLC. If connection is okay, check for faulty scan tool. See scan tool manufactures instructions and repair as necessary. If scan tool does not communicate with another vehicle, check for faulty scan tool. See scan tool manufacturer's instructions, repair as necessary and preform appropriate diagnostic system check for suspect system. See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) table.

Scheme 19

Scheme 19
Scheme 19

Circuit Description

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 DESCRIPTION & OPERATION to identify which module is the PMM and the applicable power mode look up table.

Test Description

For body control system wiring diagrams, see WIRING DIAGRAMS .

Note. Open the driver door and leave it open during this test. This will disable the RAP power mode and eliminate this power mode from the power mode parameter list.

  1. Install a scan tool. Turn OFF the ignition. With a scan tool, under the Diagnostic Circuit Check menu observe the Class 2 Power Mode parameter. Does the displayed power mode parameter match the actual ignition switch position? If yes, go to next step. If no, go to step 6 .
  2. Turn the ignition switch to the UNLOCK position. With a scan tool, under the Diagnostic Circuit Check menu observe the Class 2 Power Mode parameter. Does the displayed power mode parameter match the actual ignition switch position? If yes, go to next step. If no, go to step 6 .
  3. Turn ON the ignition, with the engine OFF. With a scan tool, under the Diagnostic Circuit Check menu observe the Class 2 Power Mode parameter. Does the displayed power mode parameter match the actual ignition switch position? If yes, go to next step. If no, go to step 6 . NOTE: The engine may start during this procedure. Turn the ignition OFF after verifying this power mode.
  4. Turn the ignition switch to the CRANK position. With a scan tool, under the Diagnostic Circuit Check menu observe the Class 2 Power Mode parameter. Does the displayed power mode parameter match the actual ignition switch position? If yes, go to next step. If no, go to step 6 .
  5. Turn the ignition switch to the ACCY position. With a scan tool, under the Diagnostic Circuit Check menu observe the Class 2 Power Mode parameter. Does the displayed power mode parameter match the actual ignition switch position? If yes, go to «TESTING FOR INTERMITTENT AND POOR CONNECTIONS»(/chevrolet/impala/viii-1999-2006/remont/body-electrical/#testing-wiring-systems-for-intermittent-poor-connections) . If no, go to next step. NOTE: The engine may start during this procedure. Turn the ignition OFF after verifying this power mode.
  6. This step tests for battery voltage on the signal circuits that are not required. Turn OFF the ignition. Disconnect the PMM. Hold the ignition switch in the position that indicated the incorrect power mode. With a test lamp attached to a good ground, test the PMM ignition switch inputs for voltage. Refer to «DESCRIPTION & OPERATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__description-operation) . Is voltage present on only the inputs specified for the ignition switch position? If yes, go to next step. If no, go to step 8 . NOTE: The engine may start during this procedure. Turn the ignition OFF after verifying this power mode.
  7. This step tests for no battery voltage on the required signal circuits. Hold the ignition switch in the position that indicated the incorrect power mode. With a test lamp attached to a good ground, test the PMM ignition switch inputs for voltage. Refer to «DESCRIPTION & OPERATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__description-operation) . Is voltage not present on any inputs specified for the ignition switch position? If yes, go to step 9 . If no, go to step 11 .
  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. Disconnect the ignition switch. Test the PMM ignition switch input circuits for a short to voltage. Test the PMM ignition switch circuits for a short between circuits. Did you find and correct the condition? If yes, go to step 14 . If no, go to step 10 .
  9. This step eliminates open circuits as the cause of the malfunction. Disconnect the ignition switch. Test the PMM ignition switch input circuits for an open. Did you find and correct the condition? If yes, go to step 14 . If no, go to next step.
  10. Inspect for poor connections and terminal tension at the harness connector of the ignition switch. Refer to «TESTING FOR INTERMITTENT AND POOR CONNECTIONS»(/chevrolet/impala/viii-1999-2006/remont/body-electrical/#testing-wiring-systems-for-intermittent-poor-connections) . Did you find and correct the condition? If yes, go to step 14 . If no, go to step 12 .
  11. Inspect for poor connections and terminal tension at the harness connector of the PMM. Refer to «TESTING FOR INTERMITTENT AND POOR CONNECTIONS»(/chevrolet/impala/viii-1999-2006/remont/body-electrical/#testing-wiring-systems-for-intermittent-poor-connections) . Did you find and correct the condition? If yes, go to step 14 . If no, go to step 13 .
  12. Replace the ignition switch. Refer to «IGNITION SWITCH»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules) . After replacement is complete, go to step 14 . NOTE: After replacement of the PMM perform the set up procedure if required.
  13. Replace the PMM. Refer to Control Module References. After replacement is complete, go to next step.
  14. Reconnect all disconnected components. With a scan tool, under the Diagnostic Circuit Check menu observe the Class 2 Power Mode parameter. Cycle the ignition switch through all possible positions one at a time. Does the displayed power mode parameter match the actual ignition switch position? If yes, system is okay. If no, go to step 1 .

Removal & Installation

CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.

Disconnect negative battery cable. Remove left instrument panel insulator. Disconnect BCM harness connectors. Push up on module, and pull bottom away from and out of mounting bracket slot. (Scheme 20) Remove module from vehicle. To install, reverse removal procedure. Ensure appropriate relearn procedures are performed. See BODY CONTROL MODULE under PROGRAMMING.

Scheme 20

Scheme 20
Scheme 20

Removal & Installation (Without Sunroof)

CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Disconnect negative battery cable. Remove overhead console cover retaining screw and remove cover. Release tabs on each side of overhead console assembly and remove overhead console assembly from headliner. (Scheme 21) Disconnect wiring harness connectors. Remove Driver Information Center (DIC) retaining screws and remove DIC.
  2. To install, reverse removal procedure. Calibrate compass on new DIC. See «COMPASS CALIBRATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__compass-calibration) under PROGRAMMING.

Removal & Installation (With Sunroof)

CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Disconnect negative battery cable. Remove overhead console cover retaining screw and remove cover. Release tabs on each side of overhead console assembly and remove overhead console assembly from headliner. (Scheme 21) Disconnect wiring harness connectors.
  2. Remove sunshade anchors. Lower headliner at sunroof opening. Reach between headliner and roof to remove foam tape from wiring harness on overhead console backing plate. Adjust wiring harness for access. Slide overhead console backing plate forward and remove backing plate from front of headliner. (Scheme 22)
  3. To install, reverse removal procedure. Calibrate compass on new DIC. See «COMPASS CALIBRATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__compass-calibration) under PROGRAMMING.

Scheme 21

Scheme 21
Scheme 21

Scheme 22

Scheme 22
Scheme 22

ELECTRONIC BRAKE CONTROL MODULE

Note. To prevent equipment damage, never connect or disconnect wiring harness connection from EBCM with ignition switch in RUN position.

Removal

  1. Clean area around oil fill cap before removing oil fill cap. Remove oil fill cap. Lift engine cover up at front and slide tab out of engine bracket. Replace oil fill cap.
  2. Remove electrical harness push-in connector from front end sheet metal diagonal brace. Remove bolt from front end sheet metal diagonal brace at inner fender. Remove bolts from front end sheet metal diagonal brace at radiator support. Remove front end sheet metal diagonal brace.
  3. Disconnect accelerator and cruise control cable from accelerator control cable bracket. From left strut tower, remove electrical connector from cruise control module. Remove cruise control module shock tower nuts. Disconnect cruise control module from left strut tower. It is not necessary to remove cable from module. Position module and cables aside.
  4. On 3.4L engine, loosen 2 intake air duct clamps from air cleaner assembly and throttle body. Disconnect Intake Air Temperature (IAT) sensor electrical connector. Remove intake air duct/Mass Air Flow (MAF) sensor from air cleaner assembly and throttle body. Loosen clamp on MAF sensor and separate intake air duct from MAF sensor.
  5. On 3.8L engine, disconnect IAT sensor electrical connector. Remove 3 bolts from inner fender brace and remove brace. Loosen clamp securing air intake duct to air cleaner housing. Carefully remove air intake duct from throttle body and air cleaner housing. Remove 2 screws from 2 air cleaner housing sections. Remove air cleaner housing cover assembly. Without disconnecting PCM connectors, remove PCM and harness from PCM housing. Carefully remove PCM housing by pulling housing from 2 rubber grommets in engine compartment. Inspect assembly for signs of damage and replace as necessary.
  6. On all engines, disengage red locking tab from connector lock tab. Push down lock tab and move sliding connector cover to open position. Disconnect EBCM harness connector. Remove any dirt/debris from assembly. Remove four EBCM to BPMV retainers. Separate EBCM from BPMV by gently pulling apart until separated.

Installation

CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Install EBCM to BPMV. Install four retainers that attach EBCM to BPMV. Connect EBCM harness connector. Push down lock tab and move sliding connector cover back in home position to lock. Reengage red locking tab to connected lock tab. Connect accelerator and cruise control cable to accelerator control cable bracket.
  2. On 3.4L engine, assemble intake air duct and MAF sensor. Install assembly to throttle body and air cleaner assembly. Secure 3 clamps on intake air duct/MAF sensor assembly.
  3. On 3.8L engine, carefully install PCM housing by pushing housing into 2 rubber grommets in engine compartment. Carefully reinstall PCM and harness into PCM housing. Install air cleaner housing cover assembly. Install 2 screws into 2 air cleaner housing sections. Carefully install air intake duct to throttle body and air cleaner housing. Install air intake duct to air cleaner housing. Position inner fender brace and reinstall 3 bolts. Connect IAT Sensor electrical connector.
  4. On all engines, if cruise control cable has been disconnected from cruise control module, perform following: On Impala, disengage cruise control cable adjuster lock by spreading adjuster lock tabs and pulling adjuster lock out. Slide cruise control cable adjuster forward, away from cruise control module. Remove as much cruise control cable slack as possible without moving throttle lever. Engage cruise control cable adjuster lock by pushing adjuster lock in. On Monte Carlo, disengage cruise control cable adjuster lock by clamping side of cruise control cable adjuster lock with a pair of pliers and pull adjuster lock out. Slide adjuster forward to take slack out of cable or slide adjuster backward to slacken cable. Make adjustments without moving throttle lever. Engage cruise control cable adjuster lock by pushing adjuster lock in towards throttle lever.
  5. On all models, install cruise control module on mounting studs located on shock tower. Install cruise control module mounting nuts. Install electrical connector to cruise control module. If cruise control cable had been removed, install cable and adjust as follows.
  6. Align front end sheet metal diagonal brace to radiator support and to inner fender. Install bolts to front end sheet metal diagonal brace at radiator support. Tighten front end sheet metal diagonal brace at radiator support bolts to 18 ft. lbs (25 N.m). Install bolts to front end sheet metal diagonal brace at inner fender. Tighten front end sheet metal diagonal brace to inner fender bolts to 35 ft. lbs (47 N.m). Install electrical harness push-in connector to brace. Close hood.
  7. Remove oil fill cap. Insert tab of fuel injector sight shield under engine bracket. Place hole of engine cover. Install oil fill cap.
  8. Turn ignition switch to RUN position, DO NOT start engine. Perform anti-lock brake system diagnostic system check. See «ANTI-LOCK BRAKE SYSTEM DIAGNOSTIC SYSTEM CHECK»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__anti-lock-brake-system-diagnostic-system-check) .

Removal (Impala)

  1. Remove instrument panel cluster trim plate. See «INSTRUMENT PANEL CLUSTER TRIM PLATE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules).
  2. Apply park brake. Place transaxle shift lever in 2nd gear. Open storage compartment door. Carefully pry rear of trim plate away from front floor console. Pull trim plate towards rear of vehicle in order to disengage front of trim plate. (Scheme 23) Remove console shift control bezel. Disconnect electrical connector at rear of front floor console trim plate. Rotate trim plate 180 degrees. Lift trim plate over shift control handle. Disconnect wiring harness retainers from trim plate. Disconnect ashtray lamp and wiring harness. Disconnect cigar lighter electrical connector. Remove ashtray. Remove front floor console trim plate.
  3. Remove front floor console bolts near instrument panel, at transaxle shift control lever and under mat in rear bin. Pull console rearward in order to disengage clips from instrument panel. (Scheme 24) Disconnect electrical connectors. Remove front floor console.
  4. Remove retaining screws from HVAC control module. Pull HVAC control module out from instrument panel. Disconnect electrical connectors from HVAC control module. Disconnect vacuum connectors from HVAC control module. Remove HVAC control module from instrument panel.

Scheme 23

Scheme 23
Scheme 23

Scheme 24

Scheme 24
Scheme 24

Removal (Monte Carlo)

  1. Remove instrument panel cluster trim plate. See «INSTRUMENT PANEL CLUSTER TRIM PLATE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules).
  2. Apply park brake. Place transaxle shift lever in 2nd gear. Remove front floor console trim plate screw located between instrument panel and shift lever. (Scheme 25)
  3. Open storage compartment door. Lift trim plate up and slightly rearward. Remove wiring harnesses from retainers. Disconnect traction control switch electrical connector. Remove shift lever trim plate. Disconnect heated seat switches from trim plate. Remove trim plate by lifting trim plate slightly and rotating trim plate 180 degrees. Lift trim plate over shift control handle. (Scheme 26) Disconnect electrical connector from cigarette lighter.
  4. Disconnect wiring harness connector and retainer. Open console storage compartment. Remove storage compartment mat. Remove bolts from bottom of storage compartment. Remove console bolts forward of shift control lever. Remove front floor console. (Scheme 27)
  5. Remove retaining screws from HVAC control module. Pull HVAC control module out from instrument panel. Disconnect electrical connectors from HVAC control module. Disconnect vacuum connectors from HVAC control module. Remove HVAC control module from instrument panel.

Scheme 25

Scheme 25
Scheme 25

Scheme 26

Scheme 26
Scheme 26

Scheme 27

Scheme 27
Scheme 27

Installation (Impala)

CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Connect electrical connectors HVAC control module. Connect vacuum connectors to HVAC control module. Install HVAC control module into instrument panel. Install retaining screws to secure HVAC control module.
  2. Position front floor console to vehicle. Connect electrical connectors. Install front floor console. Engage clips at instrument panel. Install front floor console bolts to near instrument panel, at transaxle shift control lever and under mat in rear bin.
  3. Install front floor console trim plate. Install ashtray. Connect cigar lighter electrical connector. Install ashtray lamp and wiring harness. Connect wiring harness retainers to trim plate. Lower trim plate over shift control handle. Rotate trim plate 180 degrees. Connect electrical connector at rear of trim plate. Install console shift control bezel. Engage trim plate. Ensure that retainers are completely engaged. Close storage compartment door. Place transaxle shift lever in Park. Release park brake.

Installation (Monte Carlo)

  1. Connect electrical connectors HVAC control module. Connect vacuum connectors to HVAC control module. Install HVAC control module into instrument panel. Install retaining screws to secure HVAC control module.
  2. Install front floor console. Install console bolts forward of shift control lever and at bottom of storage bin. Install storage compartment mat. Close console storage compartment. Connect wiring harness connector and retainer.
  3. Install trim plate screw located between instrument panel and shift lever. Position transaxle shift lever in Park. Release park brake.
  4. Lower front floor console trim plate over shift control handle as shown. Rotate trim plate 180 degrees. Connect electrical connector to cigarette lighter. Connect heated seat switches to trim plate. Install shift lever trim plate. Connect traction control switch electric connector. Install wiring harnesses to retainers. Install trim plate by pressing down on retainers until fully seated.

Note. Door, trunk and ignition are operated by one key. If procedure requires ignition switch lock cylinder to be replaced, new ignition switch lock cylinder should be recorded to old key.

Note. Passlock(tm) sensor is an integral part of ignition switch assembly.

  1. Disconnect negative battery cable. Remove access cover from left instrument panel fuse block. Release left instrument panel insulator tabs from lower instrument panel trim pad retainers for access. Remove bolts from steering column filler panel. Release steering column filler panel retainers from instrument panel lower trim panel. Carefully lower panel away from instrument panel lower trim panel. Disconnect electrical connector from rear compartment release switch. Remove rear compartment release switch. Remove steering column filler panel. (Scheme 28)
  2. Remove bracket bolts from instrument panel driver knee bolster. (Scheme 29) Remove bracket bolts from instrument panel knee bolster at instrument carrier. Remove knee bolster bracket.
  3. Remove instrument panel cluster trim plate. See «INSTRUMENT PANEL CLUSTER TRIM PLATE»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules). Remove ignition switch retaining bolts. (Scheme 30) Lower ignition switch away from instrument carrier.
  4. Insert key into ignition switch and turn to RUN position. If ignition switch lock cylinder rotates, go to step 8. If ignition switch lock cylinder will not rotate or is seized, go to next step.
  5. Protect immediate work area with clean shop towels or a clean fender cover. Locate surface for ignition switch lock cylinder release button (2) on plastic ignition switch housing and center punch a location (1) on rib approximately 3/8 inch toward key entry end from cylinder release button. (Scheme 31)
  6. Carefully drill a pilot hole through plastic housing with a 1/8 inch drill bit. Carefully drill a larger hole at pilot location, and slightly into ignition switch lock cylinder surface to break release button retaining spring using a 9/32 inch drill bit. Remove portions of broken spring from hole using a small suitable tool.
  7. Grasp ignition switch lock cylinder and remove it from switch housing. Remove any plastic from drilling operation, and using compressed air blow out ignition switch assembly. Go to next step.
  8. Depress transaxle park/lock cable retainer to release. Pull to remove park/lock cable from ignition switch. Depress detent on bottom of ignition switch in order to release ignition lock cylinder. Remove ignition lock cylinder with key. Disconnect Passlock(tm) electrical connector. Disconnect electrical connectors.
CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Connect electrical connectors. Connect Passlock(tm) electrical connector. Connect park/lock cable to ignition switch. Turn key to run position. Install ignition lock cylinder into ignition switch. If ignition switch lock cylinder rotated, go to step 3. If ignition switch lock cylinder did not rotate or was seized, go to next step.
  2. Install new ignition switch lock cylinder by rotating both cylinder and ignition switch to RUN position. Push ignition switch lock cylinder into ignition switch housing until fully seated. It may be necessary to slightly depress release button as it passes by 9/32" hole previously drilled in ignition switch housing. Remove key.
  3. Ensure to tighten knee bolster bracket bolt in sequence, as illustrated. (Scheme 29) To complete installation, reverse removal procedure.

Scheme 28

Scheme 28
Scheme 28

Scheme 29

Scheme 29
Scheme 29

Scheme 30

Scheme 30
Scheme 30

Scheme 31

Scheme 31
Scheme 31

Removal & Installation (Impala)

CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Apply parking brake. Using a small flat-bladed tool, remove bezel from ignition switch cylinder. If vehicle is equipped with a column shift, shift transaxle in to first gear. Ensure ignition key is in ignition lock cylinder.
  2. Adjust steering wheel to gain access. Remove access covers from right and left instrument panel fuse block, as required. Remove screws from instrument cluster trim plate.
  3. Starting at right end of instrument panel cluster, pull trim plate rearward. (Scheme 32) Continue working around instrument cluster trim plate until all retainers are released from instrument trim pad. Disconnect electrical connector from hazard switch and from traction control switch (if equipped). Remove instrument panel cluster trim plate. To install, reverse removal procedure.

Scheme 32

Scheme 32
Scheme 32

Removal & Installation (Monte Carlo)

CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Adjust steering when to gain access. Using a small flat-bladed tool, remove bezel from ignition switch cylinder. Remove access covers from left instrument panel fuse block. Release left instrument panel insulator tabs from lower instrument panel trim pad retainer for access. Remove bolts fro steering column filler panel.
  2. Release steering column filler panel retainers fro instrument panel lower trim panel. Carefully lower panel away from instrument panel lower trim panel. Disconnect electrical connector from rear compartment release switch. Remove rear compartment release switch. Remove steering column filler panel.
  3. Open instrument panel compartment door. Remove screw from left side of instrument panel cluster trim plate. (Scheme 33) Remove screw from right side of instrument panel cluster trim plate. (Scheme 34) If vehicle is equipped with a front floor console, position transaxle shift control lever to rear most position.
  4. Remove trim plate stating at right side of instrument panel cluster and pulling rearward, continuing until all retainers are released. (Scheme 35) Disconnect electrical connector from hazard switch. Moderately twist left side of instrument panel cluster trim plate in order to clear cluster aria from instrument panel. Remove instrument panel cluster trim plate. To install, reverse removal procedure.

Scheme 33

Scheme 33
Scheme 33

Scheme 34

Scheme 34
Scheme 34

Scheme 35

Scheme 35
Scheme 35
CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.

Note. Multifunction alarm module programing procedure is not available from manufacturer.

  1. Apply parking brake. Using a small flat-bladed tool, remove bezel from ignition switch cylinder. If vehicle is equipped with a column shift, shift transaxle in to "1" position. Ensure ignition key is in ignition lock cylinder.
  2. Adjust steering column to gain access. Remove access covers from right and left instrument panel fuse block, as required. Remove screws from instrument cluster trim plate.
  3. Starting at right end of instrument panel cluster, pull trim plate rearward. Continue working around instrument cluster trim plate until all retainers are released from instrument trim pad. Disconnect electrical connector from hazard switch and from traction control switch (if equipped). Remove instrument panel cluster trim plate.
  4. Remove screws from radio delete plate. Remove radio delete plate. Disconnect multifunction alarm module connector. Remove multifunction alarm module from instrument panel by lifting up and out. To install, reverse removal procedures.
CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.

Note. Multifunction alarm module programing procedure is not available from manufacturer.

  1. Adjust steering column to gain access. Using a small flat-bladed tool, remove bezel from ignition switch cylinder. Remove access covers from left instrument panel fuse block. Release left instrument panel insulator tabs from lower instrument panel trim pad reinter for access. Remove bolts fro steering column filler panel.
  2. Release steering column filler panel retainers fro instrument panel lower trim panel. Carefully lower panel away from instrument panel lower trim panel. Disconnect electrical connector from rear compartment release switch. Remove rear compartment release switch. Remove steering column filler panel.
  3. Open instrument panel compartment door. Remove screw from left side of instrument panel cluster trim plate. Remove screw from right side of instrument panel cluster trim plate. If vehicle is equipped with a front floor console, position transaxle shift control lever to rear most position.
  4. Remove trim plate stating at right side of instrument panel cluster and pulling rearward, continuing until all retainers are released. Disconnect electrical connector from hazard switch. Moderately twist left side of instrument panel cluster trim plate in order to clear cluster aria from instrument panel. Remove instrument panel cluster trim plate.
  5. Remove screws from radio delete plate. Remove radio delete plate. Disconnect multifunction alarm module connector. Remove multifunction alarm module from instrument panel by lifting up and out. To install, reverse removal procedures.
CAUTIONElectronic components used in control systems are designed to carry very low voltages. As little as a 30-volt charge created by static electricity can cause a total or degrading failure in PCM or other electronic components containing integrated circuits. Before servicing Powertrain Control Module (PCM), technician must ground himself and work area to discharge static electricity.
CAUTIONDO NOT remove part from packaging until ready to install. Ground any static-proof package before opening. DO NOT touch electrical terminals of components unless properly grounded. DO NOT lay electrical components on car seat, carpeting or instrument panel. Use electrostatic protection mat and ground strap whenever possible.

Note. Before replacing PCM, carefully inspect all wiring and control components. Failure to test for short circuits may result in repeated PCM failure due to shorts. To prevent internal damage to PCM, ensure ignition is off when connecting or disconnecting PCM harness connectors or any electrical components.

Note. If diagnostic procedures call for PCM replacement, check PCM first to see if part is correct. If PCM is faulty, remove PCM and install new service PCM.

CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Disconnect negative battery. Disconnect Intake Air Temperature (IAT) sensor electrical connector. Remove 3 bolts from inner fender brace and remove brace.
  2. Loosen clamp securing air intake duct to air cleaner housing. Carefully remove air intake duct from throttle body and air cleaner housing. Remove 2 screws from 2 air cleaner housing sections.
  3. Remove air cleaner housing cover assembly. Without disconnecting PCM connectors, remove PCM and harness from PCM housing. Disconnect PCM connectors.
  4. To install, reverse removal procedure. Replacement PCM will not allow secondary air pump operation until a total of 10 miles (16 km) have been accumulated. New PCM must be programmed. See POWERTRAIN CONTROL MODULE under PROGRAMMING.
CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Apply parking brake. Using a small flat-bladed tool, remove bezel from ignition switch cylinder. If vehicle is equipped with a column shift, shift transaxle in to "1". Ensure ignition key is in ignition lock cylinder.
  2. Adjust steering wheel to gain access. Remove access covers from right and left instrument panel fuse block, as required. Remove screws from instrument cluster trim plate.
  3. Starting at right end of instrument panel cluster, pull trim plate rearward. Continue working around instrument cluster trim plate until all retainers are released from instrument trim pad. Disconnect electrical connector from hazard switch and from traction control switch (if equipped). Remove instrument panel cluster trim plate.
  4. Remove screws from radio. Pull radio out of instrument panel. Disconnect instrument panel wiring harness connector and antenna cable connector from radio. Remove radio from instrument panel.
  5. To install, reverse removal procedures. Align radio locator tab to instrument panel locator opening while pressure radio into instrument panel until fully seated. After installation, preform radio set up procedure. See «RADIO SETUP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__radio-setup) under PROGRAMMING.
CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Adjust steering when to gain access. Using a small flat-bladed tool, remove bezel from ignition switch cylinder. Remove access covers from left instrument panel fuse block. Release left instrument panel insulator tabs from lower instrument panel trim pad retainer for access. Remove bolts fro steering column filler panel.
  2. Release steering column filler panel retainers fro instrument panel lower trim panel. Carefully lower panel away from instrument panel lower trim panel. Disconnect electrical connector from rear compartment release switch. Remove rear compartment release switch. Remove steering column filler panel.
  3. Open instrument panel compartment door. Remove screw from left side of instrument panel cluster trim plate. Remove screw from right side of instrument panel cluster trim plate. If vehicle is equipped with a front floor console, position transaxle shift control lever to rear most position.
  4. Remove trim plate stating at right side of instrument panel cluster and pulling rearward, continuing until all retainers are released. Disconnect electrical connector from hazard switch. Moderately twist left side of instrument panel cluster trim plate in order to clear cluster from instrument panel. Remove instrument panel cluster trim plate.
  5. Remove screws from radio. Pull radio out of instrument panel. Disconnect instrument panel wiring harness connector and antenna cable connector from radio. Remove radio from instrument panel.
  6. To install, reverse removal procedures. Align radio locator tab to instrument panel locator opening while pressure radio into instrument panel until fully seated. After installation, preform radio set up procedure. See «RADIO SETUP»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__radio-setup) under PROGRAMMING.
  1. Remove windshield pillar garnish molding from clip retainers on upper side rail. (Scheme 39) Slide roof leg of windshield pillar garnish molding out from under center pillar trim panel. Remove windshield pillar garnish molding from windshield pillar. Remove windshield pillar garnish molding from front door carpet retainer by pulling up and back. Remove windshield pillar garnish molding. Remove upper side rail clip retainers if damaged during removal of windshield pillar garnish molding, remove screw and replace retainer from upper side rail.
  2. Starting at right side of windshield, carefully lift upwards on defroster grille in order to release retainers. (Scheme 36) Continue working to left until all of retainers are released. Disconnect Daytime Running Lights (DRL) sensor from defroster grille. (Scheme 37) Remove defroster grille.
  3. Disengage Remote Control Door Lock Receiver (RCDLR) retainers. Disconnect RCDLR electrical connectors. Remove RCDLR. (Scheme 38)
CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Position RCDLR to upper instrument panel. Connect RCDLR electrical connectors.
  2. Position defroster grille to upper instrument panel. Connect DRL sensor to defroster grille. Verify that DRL sensor wiring harness will not be pinched when defroster grille is installed. Starting at left side, install defroster grille retainers into upper instrument panel. Continue working to right until all of retainers are installed.
  3. Install a new clip retainer to upper side rail, if necessary. Align windshield pillar garnish molding to front door carpet retainer and to front door weatherstrip. Align windshield pillar garnish molding to trough on upper instrument panel trim panel. Align windshield pillar garnish molding retainers to windshield pillar. Slide roof leg under center pillar trim panel. Align windshield pillar garnish molding to clip retainers on upper side rail. Install windshield pillar garnish molding, applying pressure at all retainers until fully seated.
  4. To complete installation, reverse removal procedure. Program and synchronize transmitters to new RCDLR. See «RKE TRANSMITTER PROGRAMMING»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__rke-transmitter-programming) and «TRANSMITTER SYNCHRONIZATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__transmitter-synchronization) under PROGRAMMING.

Scheme 36

Scheme 36
Scheme 36

Scheme 37

Scheme 37
Scheme 37

Scheme 38

Scheme 38
Scheme 38

Scheme 39

Scheme 39
Scheme 39

Removal (Monte Carlo, With Folding Rear Seat)

  1. Pull tabs on rear seat cushion retainers in order to release rear seat cushion. (Scheme 40) Remove rear seat cushion by lifting up and pulling out of retainer. Remove rear seat cushion from vehicle.
  2. Remove nuts from rear seat retainer at bottom of rear seat back. (Scheme 41) Fold rear seat back cushions down. Remove bolts from rear seat latches. (Scheme 42) Remove rear seat latches from rear seat back. Fold rear seat back cushions up. Reposition seat belts from rear seat back. Remove rear seat back from vehicle.
  3. Remove push-in retainers from front of rear window trim panel. Lift rear window trim panel and remove seat belts through slots in rear window trim panel. Slide rear window trim panel forward to disengage integral hook from retaining hole and remove rear window trim panel. Remove rear shelf. (Scheme 43)
  4. Remove rear seat belt retractor bolt. Remove rear seat belt anchor bolt. Remove rear seat belt retractor from vehicle.
  5. Remove push-in retainer from center of coat hook using a small flat-bladed tool. Remove coat hook from headliner. Remove rear quarter upper trim in by disengaging push-in retainers. (Scheme 44)
  6. Remove windshield pillar garnish molding from clip retainers on upper side rail. (Scheme 39) Remove windshield pillar garnish molding from windshield pillar. Remove windshield pillar garnish molding from front door carpet retainer, pulling up and back. Remove windshield pillar garnish molding from vehicle. Remove upper side rail clip retainer if damaged in removal of windshield pillar garnish molding.
  7. Starting at right side of windshield, carefully lift upwards on defroster grille in order to release retainers. (Scheme 36) Continue working to left until all of retainers are released. Disconnect Daytime Running Lights (DRL) sensor from defroster grille. (Scheme 37) Remove defroster grille.
  8. Disengage Remote Control Door Lock Receiver (RCDLR) retainers. Disconnect RCDLR electrical connectors. Remove RCDLR. (Scheme 38)
CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.

Note. When installing rear seat bolts on Monte Carlo, anti-rotation tab must be in proper hole in rear shelf.

  1. Position RCDLR to upper instrument panel. Connect RCDLR electrical connectors. Engage RCDLR retainers.
  2. Position defroster grille to upper instrument panel. Connect DRL sensor to defroster grille. Verify that DRL sensor wiring harness will not be pinched when defroster grille is installed. Starting at left side, install defroster grille retainers into upper instrument panel. Continue working to right until all of retainers are installed.
  3. Install new upper side rail clip retainer and screw if removed, to upper side rail. Align windshield pillar garnish molding to front door carpet retainer and front door weatherstrip. Align windshield pillar garnish molding to trough on upper instrument panel trim panel. Align windshield pillar garnish molding retainers to windshield pillar. Align windshield pillar garnish molding to clip retainers on upper side rail. Install windshield pillar garnish molding, applying pressure at all retainers locations until fully seated.
  4. Install coat hook into headliner. Install push-in retainer pressing into place until fully seated.
  5. Install rear seat belt retractor bolt. Tighten rear seat belt retractor bolt to 50 lbs ft (68 Nm). Install rear seat belt anchor bolt. Tighten rear seat belt anchor bolt to 31 lbs ft (42 Nm).
  6. Align rear quarter upper trim panel slotted retainers to rear quarter lower trim panel. Align rear quarter upper trim panel push-in retainers to rear quarter inner upper panel. Install rear quarter upper trim panel push-in retainers, applying pressure to secure at all push-in retainers locations.
  7. Slide rear window trim panel rearward to engage integral hook in retaining hole. Lift rear window trim panel and route seat belts through slots in rear window trim panel. Install push-in retainers in front of rear window trim panel.
  8. Position rear seat back to vehicle. Reposition seat belts to rear seat back. Install nuts to rear seat retainer at bottom of rear seat back. Fold rear seat back cushions down. Install rear seat latches to rear seat back. Install rear seat back latch bolts to rear seat latches. Fold rear seat back cushions up. Inspect rear seat for proper operation.
  9. Align seat belts to notches in rear seat cushion. Position rear seat cushion to retainers. Install rear seat cushion to retainers, engaging right side first. Inspect rear seat cushion for proper installation.
  10. To complete installation, reverse removal procedure. Program and synchronize transmitters to new RCDLR. See «RKE TRANSMITTER PROGRAMMING»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__rke-transmitter-programming) and «TRANSMITTER SYNCHRONIZATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__transmitter-synchronization) under PROGRAMMING.

Scheme 40

Scheme 40
Scheme 40

Scheme 41

Scheme 41
Scheme 41

Scheme 42

Scheme 42
Scheme 42

Scheme 43

Scheme 43
Scheme 43

Scheme 44

Scheme 44
Scheme 44

Removal (Monte Carlo, Without Folding Rear Seat)

  1. Pull tabs on rear seat cushion retainers in order to release rear seat cushion. (Scheme 40) Remove rear seat cushion by lifting up and pulling out of retainer. Remove rear seat cushion from vehicle.
  2. Remove nuts from rear seat retainer at bottom of rear seat back. (Scheme 41) Grasp bottom of rear seat back and lift upward to disengage offsets on upper frame bar from hangers. Lift rear seat back upwards to remove from rear shelf. Remove rear seat back from vehicle.
  3. Remove push-in retainers from front of rear window trim panel. Lift rear window trim panel and remove seat belts through slots in rear window trim panel. Slide rear window trim panel forward to disengage integral hook from retaining hole and remove rear window trim panel. Remove rear shelf. (Scheme 43)
  4. Remove rear seat belt retractor bolt. Remove rear seat belt anchor bolt. Remove rear seat belt retractor from vehicle.
  5. Remove push-in retainer from center of coat hook using a small flat-bladed tool. Remove coat hook from headliner. Remove rear quarter upper trim in by disengaging push-in retainers. (Scheme 44)
  6. Remove windshield pillar garnish molding from clip retainers on upper side rail. (Scheme 39) Remove windshield pillar garnish molding from windshield pillar. Remove windshield pillar garnish molding from front door carpet retainer, by pulling up and back. Remove windshield pillar garnish molding from vehicle. Remove upper side rail clip retainer if damaged in removal of windshield pillar garnish molding.
  7. Starting at right side of windshield, carefully lift upwards on defroster grille in order to release retainers. (Scheme 36) Continue working to left until all of retainers are released. Disconnect Daytime Running Lights (DRL) sensor from defroster grille. (Scheme 37) Remove defroster grille.
  8. Disengage Remote Control Door Lock Receiver (RCDLR) retainers. Disconnect RCDLR electrical connectors. Remove RCDLR. (Scheme 38)
CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.

Note. When installing rear seat bolts on Monte Carlo, anti-rotation tab must be in proper hole in rear shelf.

  1. Position RCDLR to upper instrument panel. Connect RCDLR electrical connectors. Engage RCDLR retainers.
  2. Position defroster grille to upper instrument panel. Connect DRL sensor to defroster grille. Verify that DRL sensor wiring harness will not be pinched when defroster grille is installed. Starting at left side, install defroster grille retainers into upper instrument panel. Continue working to right until all of retainers are installed.
  3. Install new upper side rail clip retainer and screw if removed, to upper side rail. Align windshield pillar garnish molding to front door carpet retainer and front door weatherstrip. Align windshield pillar garnish molding to trough on upper instrument panel trim panel. Align windshield pillar garnish molding retainers to windshield pillar. Align windshield pillar garnish molding to clip retainers on upper side rail. Install windshield pillar garnish molding, applying pressure at all retainers locations until fully seated.
  4. Install coat hook into headliner. Install push-in retainer pressing into place until fully seated.
  5. Install rear seat belt retractor bolt. Tighten rear seat belt retractor bolt to 50 lbs ft (68 Nm). Install rear seat belt anchor bolt. Tighten rear seat belt anchor bolt to 31 lbs ft (42 Nm).
  6. Align rear quarter upper trim panel slotted retainers to rear quarter lower trim panel. Align rear quarter upper trim panel push-in retainers to rear quarter inner upper panel. Install rear quarter upper trim panel push-in retainers, applying pressure to secure at all push-in retainers locations.
  7. Slide rear window trim panel rearward to engage integral hook in retaining hole. Lift rear window trim panel and route seat belts through slots in rear window trim panel. Install push-in retainers in front of rear window trim panel.
  8. Position rear seat back to vehicle. Hook seat back upper frame to hangers on rear shelf.
  9. Align seat belts to notches in rear seat cushion. Position rear seat cushion to retainers. Install rear seat cushion to retainers, engaging right side first. Inspect rear seat cushion for proper installation.
  10. To complete installation, reverse removal procedure. Program and synchronize transmitters to new RCDLR. See «RKE TRANSMITTER PROGRAMMING»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__rke-transmitter-programming) and «TRANSMITTER SYNCHRONIZATION»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__transmitter-synchronization) under PROGRAMMING.

SUPPLEMENTAL INFLATABLE RESTRAINT SYSTEM SENSING & DIAGNOSTIC MODULE

CAUTIONBe careful when you handle a inflatable restraint Sensing and Diagnostic Module (SDM). DO NOT strike or jolt SDM. Before applying power to SDM: Remove any dirt, grease, etc. from mounting surface Position SDM horizontally on mounting surface Point arrow on SDM toward front of vehicle Tighten all of SDM fasteners and SDM bracket fasteners to specified torque value. Failure to follow correct procedure could cause air bag deployment, personal injury, or unnecessary SIR system repairs.
CAUTIONIf any water enters vehicle's interior up to level of carpet or higher and soaks carpet, SDM and SDM harness connector may need to be replaced. SDM could be activated when powered, which could cause deployment of air bag(s) and result in personal injury. Before attempting these procedures, SIR system must be disabled. See SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article. With ignition OFF, inspect SDM mounting area, including carpet. If any significant soaking or evidence of significant soaking is detected, you must perform following tasks: Remove all water. Repair water damage. Replace SDM harness connector. Replace SDM. Failure to follow these tasks could result in possible air bag deployment, personal injury, or otherwise unneeded SIR system repairs.
  1. Disable Supplemental Inflatable Restraint (SIR) system. See DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.
  2. Position seat forward and in full up position. Remove covers from front end of seat adjuster track by spreading two rear tabs and pulling forward. For manual seat, remove retaining screw from rear of seat adjuster track. Remove covers from track. For power seat, use a flat-bladed tool to lift retainer tab from rear of seat adjuster track. Remove covers from track.
  3. Remove seat belt nut from front seat track. Raise front seat head restraint to full up position. Press in release tab at side of head restraint retainer. Remove front seat head restraint from front seat.
  4. Remove bolts which secure seat adjuster to floor pan at rear of seat. Disengage seat hook attachments from floor pan. Tip seat back and disconnect power seat (if equipped), electrical seat heater (if equipped) and driver side air bag (if equipped) electrical connector. Remove front bucket seat.
  5. Remove passenger front carpet retainer and roll back carpet. Remove Connector Position Assurance (CPA) from inflatable restraint Sensing and Diagnostic Module (SDM) wiring harness connector. Disconnect SDM wiring harness connector from SDM. Remove SDM mounting fasteners. (Scheme 45) Remove SDM from floor pan.

Scheme 45

Scheme 45
Scheme 45
CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
  1. Install SDM to floor pan. Install SDM mounting fasteners. Tighten fasteners to 89 in. lbs (10 N.m).
  2. Install SDM wiring harness connector to SDM. Install CPA to SDM wiring harness connector. Install carpet and passenger front carpet retainer. Enable air bag system. See «ENABLING AIR BAG SYSTEM»(/chevrolet/impala/viii-1999-2006/remont/communication-devices/#body-control-modules__enabling-air-bag-system) under PROGRAMMING.
  3. Install bolts which secure front bucket seat adjuster to floor pan. Tighten bolts to 31 ft. lbs (42 N.m). Install seat belt nut to front seat stud. Tighten nut to 31 ft. lbs (42 N.m). Inspect seat for proper operation and adjustment. Position seat to original position.
  4. Position front bucket seat into place. Tip seat back and connect following connectors, if equipped. Power seat electrical connector electrical seat heater connector driver side air bag electrical connector Engage seat hook attachments to floor pan.
  5. Align head restraint to head restraint retainers in front seat back. Install head restraint to front seat, pressing down until fully seated. Raise head restraint to full up position to ensure head restraint stops at detent. Position head restraint to its original position.
  6. For power seat, install covers to rear of seat adjuster track. For manual seat, position covers to rear of seat adjuster track. Insert a screw to secure each track cover. Install covers to front of seat adjuster track.

VEHICLE INTERFACE UNIT

Note. DO NOT exchange OnStar(R) Vehicle Interface Unit (VIU), or Vehicle Communication Units (VCU) from other vehicles. Transfer of OnStar(R) components from other vehicles should not be done. Each OnStar(R) component has a unique identification number. VIU has a 10-digit specific Station Identification (STID) and VCU has a 11-digit specific Electronic Serial Number (ESN). These identification numbers are used by National Cellular Telephone Network and OnStar(R) systems, and are stored in General Motors vehicle history files by VIN.

  1. Open rear compartment. Remove cover from OnStar(R) Vehicle Communication Unit (VCU) by depressing retainer tabs. Remove cellular coaxial cable from VCU by pulling off. Remove screws from connector. Remove connector from VCU. Release retainer strap from VCU using a small flat-bladed tool. Remove VCU from rear compartment.
  2. Remove nuts from VIU/VCU bracket. Remove VIU from inner wheel housing. Disconnect Global Positioning System (GPS) antenna cable from VIU.
  3. Disconnect red 32-pin connector from VIU. Disconnect blue 32-pin connector from VIU. Remove mounting screws from VIU. Remove VIU from VIU/VCU bracket.
CAUTIONUse correct fastener in correct location. Replacement fasteners must be correct part number for application. Fasteners requiring replacement or fasteners requiring use of thread locking compound or sealant are identified in service procedures. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage fastener. Use correct tightening sequence and specifications when installing fasteners in order to avoid damage to part and systems.
CAUTIONIn order to avoid damage to circuit board, DO NOT over-tighten thumb screws. Using your fingers, apply only a light pressure.
  1. Record 10-digit STID number from label on VIU module. Position VIU to VIU/VCU bracket. Install OnStar(R) mounting bracket screws to VIU. Connect GPS antenna cable to VIU. Connect red 32-pin connector to VIU.
  2. Position VIU to inner wheel housing. Install OnStar(R) mounting bracket nuts to VIU/VCU bracket. Contact OnStar(R) Dealer Support line by pressing OnStar(R) button twice. 10-digit STID number recorded will be needed by OnStar(R) Dealer Support line.
  3. Record 11-Digit ESN number from label on new part. Install cellular coaxial cable to VCU pressing into place until fully seated. Install connector to VCU pressing into place until fully seated. Hand tighten screws to connector. Position VCU to top of VIU. Install retainer strap to VCU pressing into place until fully seated.
  4. Press and hold end call button, which is a black button with a white dot. OnStar status light will change from green to red to green. Contact OnStar Dealer support line by pressing blue OnStar button twice. ESN number will be needed by OnStar advisor. Close rear compartment.

WIRING DIAGRAMS

For 2001 wiring, see BODY COMPUTER in SYSTEM WIRING DIAGRAMS in ELECTRICAL.

For 2002 wiring, see BODY COMPUTER in SYSTEM WIRING DIAGRAMS in ELECTRICAL.

See also:
• TESTING FOR INTERMITTENT AND POOR CONNECTIONS
• PROGRAMMING THEFT DETERRENT SYSTEM COMPONENTS
• BODY CONTROL MODULE PROGRAMMING/REGULAR PRODUCTION OPTION CONFIGURATION
• COMPASS MAGNETIC VARIATION ADJUSTMENT
• AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK
• DIAGNOSTIC TROUBLE CODE DEFINITIONS
• SELF-DIAGNOSTIC SYSTEM
• INTERMITTENT SIMULATION
• TEST D: SCAN TOOL DOES NOT POWER UP
• ANTI-LOCK BRAKE SYSTEM DIAGNOSTIC SYSTEM CHECK
• AUDIBLE WARNINGS SYSTEM DIAGNOSTIC SYSTEM CHECK
• BODY REAR END SYSTEM DIAGNOSTIC SYSTEM CHECK
• CELLULAR COMMUNICATION SYSTEM DIAGNOSTIC SYSTEM CHECK
• CRUISE CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECK
• REAR WINDOW DEFOGGER SYSTEM DIAGNOSTIC SYSTEM CHECK
• ENGINE COOLING SYSTEM DIAGNOSTIC SYSTEM CHECK
• HORNS SYSTEM DIAGNOSTIC SYSTEM CHECK
• INSTRUMENT PANEL CLUSTER SYSTEM DIAGNOSTIC SYSTEM CHECK
• LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK
• DOOR SYSTEM DIAGNOSTIC SYSTEM CHECK
• POWER SUN ROOF SYSTEM DIAGNOSTIC SYSTEM CHECK
• POWERTRAIN CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECK
• REMOTE KEYLESS ENTRY SYSTEM DIAGNOSTIC SYSTEM CHECK
• RETAINED ACCESSORY POWER (RAP) SYSTEM DIAGNOSTIC SYSTEM CHECK
• ANTI-THEFT SYSTEM DIAGNOSTIC SYSTEM CHECK
• TIRE PRESSURE MONITORING SYSTEM DIAGNOSTIC SYSTEM CHECK
• SYSTEM TESTS
• ENGINE ELECTRICAL SYSTEM DIAGNOSTIC SYSTEM CHECK
• DIAGNOSTIC AIDS
• CODE ENABLE CRITERIA
• WIRING DIAGRAMS
• REMOVAL & INSTALLATION
• A
• B
• DESCRIPTION & OPERATION
• COMPASS CALIBRATION
• RADIO SETUP
• RKE TRANSMITTER PROGRAMMING
• TRANSMITTER SYNCHRONIZATION
• ENABLING AIR BAG SYSTEM

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