Body Control Module Cadillac Catera I

DESCRIPTION & OPERATION

The Body Control Module (BCM) performs the following functions: battery guard, door lock and unlock (including keyless entry), various telltale controls in instrument cluster and headlight switch, retained accessory power, theft deterrent, exterior and interior lighting control, trunk release, fuel door release, and class 2 diagnostic protocol.

Signals that activate the BCM are known as "wake-up" signals. BCM wake-up signals include any ignition state transition, door switch activated or trunk opened with ignition switch in LOCK position, or any class 2 communication requiring BCM interaction. BCM also has a low power current sense feedback, which will wake-up BCM if current feedback sense is over 2.4 amps.

After BCM is awakened, it will enter a high power mode. If no further activity occurs within 15 minutes, it will enter a low power ("asleep") mode. After 3 days and 15 minutes, BCM will convert to a no controlled power mode. Both low and high power will be deactivated until a wake-up signal is received.

Battery guard feature provides protection from excessive battery drain caused by high current loads that are accidentally left on. BCM controls battery power regulation by using a low power driver and a high power control of battery guard relay to the following components: Radio receiver, Radio Interface Module (RIM), fuel door relay coil, trunk release relay coil and phone (dealer installed).

Retained Accessory Power (RAP) feature allows use of the radio and phone systems after ignition is turned off. If ignition switch is still in LOCK position after 10 minutes, RAP feature is disabled. If any door is opened or closed during the 10-minute period, RAP feature will be disabled. RAP feature will also disable if ignition switch is turned to START position.

BCM uses class 2 serial data line to communicate with the following modules: Cellular telephone, radio (including clock, tape player and CD player), remote control door lock receiver, and sound processor interface. Class 2 serial data uses the peer-to-peer method and message arbitration to manage data line traffic. Communication on the class 2 serial data line is performed on an "as needed" basis.

BCM acts as an interface between the optional OnStar vehicle communication system and the vehicle architecture. The Vehicle Interface Unit (VIU) will send the following class 2 messages to the BCM: Door unlock or lock activation, horn control, interior light control and exterior light control (will override daytime running light, twilight sentinel or wiper-on lighting modes). BCM is hard-wired to air bag restraint sensing module. If air bag is deployed, BCM will send a class 2 message to VIU to indicate a restraint system was activated.

COMPONENT LOCATIONS

COMPONENT LOCATIONS

Scheme 1

PROGRAMMING

Note. When BCM is replaced, it must be programmed with the Vehicle Identification Number (VIN). The VIN is used by radio theftlock feature to ensure that radio has not been removed and improperly installed.

To program BCM, enter VIN using scan tool. Scan tool will send a class 2 message to BCM, which will store VIN in its Electronically Erasable Programmable Read Only Memory (EEPROM). When BCM first communicates with radio, radio theftlock will be re-armed.

When ignition switch is turned to ON position, radio requests part of VIN from BCM. BCM sends requested VIN to radio, which compares it to VIN stored in radio EEPROM. If the VIN sent by BCM does not match, radio will disable all entertainment function and display a message indicating that it is in locked mode. Radio will remain locked until it receives a proper VIN.

When radio is replaced, location of VIN in its EEPROM must be in default mode (reset as necessary using scan tool). When BCM first communicates with radio, radio theftlock will be re-armed. If a power loss to BCM or radio occurs, radio theftlock will re-arm after initial communication between the 2 components. If class 2 communication does not resume, radio will enter locked mode.

INTRODUCTION

Body Control Module (BCM) is equipped with a self-diagnostic system, which detects system Diagnostic Trouble Codes (DTCs) or abnormalities. When a malfunction occurs, BCM will store a DTC. See BCM DTC DEFINITIONS . Malfunctions are recorded as history/intermittent failures or as current failures. Current DTCs indicate BCM has detected a fault which is currently present. A history DTC indicates that BCM has previously detected a malfunction that is not currently present.

A scan tool can be used to retrieve and clear DTCs. The scan tool also has several features that can be used to help locate an intermittent condition. When scan tool is used for system tests, it will display values actually seen or commanded by various systems (i.e., BCM, PCM). This will usually include the following types of information

1. Analog Data Input - Displays analog input seen by system.
2. Inputs/Outputs - Displays digital values as seen by system, and provides indication of whether input or output has cycled.
3. Special Functions (Output Controls) - Allows for outputs of system to be set at a desired value (ON or OFF). This will only indicate if BCM is sending the appropriate commands, not what action was actually taken.
4. Clear Codes - Will erase DTCs for system currently selected (if problem still exists in system, DTC may immediately reset).

CLEARING DTCS

If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. To manually clear DTCs, use scan tool or press RESET button on IPC's Driver Information Center (DIC).

BCM DTC DEFINITIONS

BCM DTC DEFINITIONS (1)

DIAGNOSTIC TESTS

Note. For wiring and connector terminal identification, see WIRING DIAGRAMS .

BCM SYSTEM CHECK

Note. Use this check as the starting point for any BCM complaint. BCM is a very reliable component, and is not likely the cause of malfunction. Most malfunctions are caused by faulty wiring, connectors or components.

1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Attempt to establish communication with BCM. If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, go to step 3).
2. Using scan tool, check for BCM DTCs. If any DTC exists, go to appropriate DTC test. If no DTCs exist, system is operating properly.
3. Attempt to establish communication with other systems connected to same serial data line (PCM, RFA, etc.). If scan tool communicates with other systems, go to next step. If scan tool does not communicate with other systems, locate and repair problem in serial data line. See DATA LINK CONNECTORS in «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) .
4. Ensure ignition is on. Using a test light, probe between each BCM fuse and ground. See «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) . If test light illuminates at all circuits, go to next step. If test light does not illuminate at all circuits, go to step 9).
5. Turn ignition off. Disconnect BCM 24-pin connector C1 and 32-pin connector C2. Turn ignition on. Using a test light connected to ground, probe each BCM power circuit. See «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) . If test light illuminates at all circuits, go to next step. If test light does not illuminate at all circuits, go to step 11).
6. Using a test light connected to battery, probe each BCM ground circuit. See «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) . If test light illuminates at all circuits, go to next step. If test light does not illuminate at all circuits, go to step 12).
7. Using DVOM, check for continuity between BCM 24-pin harness connector C1, terminal B9 (Brown/White wire) and Data Link Connector (DLC) terminal No. 2 (Brown/White wire). If continuity exists, go to next step. If continuity does not exist, go to step 10).
8. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming) . Go to step 13).
9. Repair open in ignition or battery feed to BCM fuse. If any fuse is open, locate and repair short in associated circuit. See «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) . Go to step 13).
10. Locate and repair open in Brown/White wire between BCM connector C1 and DLC. Go to step 13).
11. Locate and repair open in BCM power circuit. Go to step 13).
12. Locate and repair open in BCM ground circuit. Go to next step.
13. Turn ignition off. Reinstall all components or connectors. Clear DTCs. Ensure system is operating properly.

Diagnostic Aids

1. The following conditions may result in intermittent operation of BCM with no DTC stored: Any condition which results in interruption of power to BCM. Out of range battery or ignition voltage (normal BCM operating voltage is 9-16 volts). Loose or damaged ground(s). Open or shorted serial data line.
2. BCM tests for different malfunctions during different vehicle conditions. A thorough test drive may be necessary to repeat malfunction. Most intermittent problems are caused by faulty electrical connections or wiring. Check for: poor connections, backed-out terminals, dirty or corroded terminals, chafed wires, or damaged connectors.

DTC U1128: LOSS OF SERIAL COMMUNICATIONS - IRC

Note. To identify wire colors and components on class 2 serial data line, see DATA LINK CONNECTOR in WIRING DIAGRAMS .

Every 2 seconds while ignition switch is in RUN position, control modules that communicate on class 2 data bus transmit a performance condition signal to indicate system is operating properly. Signal is then transmitted to BCM.

DTC U1128 will set when voltage to Internal Radio Controller (IRC) is in normal operating range (9-16 volts), DTCs U1300 and U1301 are not current, and BCM does not receive signal from IRC for five seconds. DTC U1128 will clear when IRC transmits signal to BCM (current DTC) or when scan tool is used (history DTC).

Testing

1. Using scan tool, verify that communication can be established with radio receiver. Operate radio to ensure that entertainment system is powered properly. If radio system is powered properly, go to next step. If radio system is not powered properly, repair as necessary and go to step 6).
2. Turn ignition switch to OFF position. Disconnect radio receiver. Check for poor connection at radio receiver terminal F6 (Brown/White wire). Repair as necessary and go to step 6). If connection is okay, go to next step.
3. Using DVOM, check resistance of Brown/White wire between radio receiver terminal F6 and Data Link Connector (DLC) terminal No. 2. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, go to step 5)
4. Replace and program radio receiver. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming) . Go to step 6).
5. Repair open in Brown/White wire between radio and DLC. Go to next step.
6. Turn ignition switch to ON position. Check for loss of class 2 communication codes (U1000 through U1255) in radio receiver and BCM. Clear codes from both components. Recheck system operation.

DTC U1255: GENERIC LOSS OF CLASS 2 DEVICES

Note. To identify wire colors and components on class 2 serial data line, see DATA LINK CONNECTORS in WIRING DIAGRAMS .

During normal vehicle operation, modules on class 2 serial data line monitor data line to exchange operating information and commands. Modules on serial data line send a State Of Health (SOH) message about every 2 seconds to verify system is operating properly.

DTC U1255 will set when system voltage is in normal operating range (9-16 volts) and BCM and radio receiver detect no messages on class 2 serial data line. A current DTC U1255 will clear when a valid class 2 message is detected or at end of current ignition cycle. A history DTC U1255 will clear when scan tool is used.

A current DTC U1255 cannot be retrieved. Check for intermittent short to ground on class 2 serial data line. See DATA LINK CONNECTOR in WIRING DIAGRAMS .

DTC U1300: CLASS 2 SHORT TO GROUND

Note. To identify wire colors and components on class 2 serial data line, see DATA LINK CONNECTORS in WIRING DIAGRAMS .

During normal vehicle operation, modules on class 2 serial data line monitor data line to exchange operating information and commands. Modules on serial data line send a State Of Health (SOH) message about every 2 seconds to verify system is operating properly.

DTC U1300 will set when system voltage is in normal operating range (9-16 volts), BCM and radio receiver detect no messages on class 2 serial data line, and a low voltage level is detected for 3 seconds. When DTC U1300 is set, no other communication DTCs can be set. A current DTC U1300 will clear when a valid class 2 message is detected or at end of current ignition cycle. A history DTC U1300 will clear when scan tool is used.

A current DTC U1300 cannot be retrieved. Check for intermittent short to ground on class 2 serial data line. See DATA LINK CONNECTOR in WIRING DIAGRAMS .

DTC U1301: CLASS 2 SHORT TO BATTERY

Note. To identify wire colors and components on class 2 serial data line, see DATA LINK CONNECTOR in WIRING DIAGRAMS .

During normal vehicle operation, modules on class 2 serial data line monitor data line to exchange operating information and commands. Modules on serial data line send a State Of Health (SOH) message about every 2 seconds to verify system is operating properly.

DTC U1301 will set when system voltage is in normal operating range (9-16 volts), BCM and radio receiver detect no messages on class 2 serial data line, and a high voltage level is detected for 3 seconds. When DTC U1301 is set, no other communication DTCs can be set. A current DTC U1301 will clear when a valid class 2 message is detected or at end of current ignition cycle. A history DTC U1301 will clear when scan tool is used.

A current DTC U1301 cannot be retrieved. Check for intermittent short to ground on class 2 serial data line. See WIRING DIAGRAMS .

DTC B1552: LOSS OF BCM KEEP ALIVE MEMORY (KAM)

DTC B1552 indicates keep alive memory or long term memory has been reset. Keep alive memory or long term memory will reset when power or ground is removed from BCM. This is a normal occurrence when battery is disconnected and reconnected.

When DTC B1552 is set, BCM memory is reset to initial default values. DTC B1552 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

If DTC B1552 is set and battery was not disconnected, check for poor connections at BCM 24-pin connector C1, terminal B03 (Red wire) and BCM 32-pin connector C2, terminal C01 (Black wire).

DTC B1556: BCM EEPROM WRITE ERROR

DTC B1556 testing is run for each write block of writes to EEPROM. BCM writes to EEPROM cell and then reads data back. DTC B1556 will set when data read by BCM does not match data written to EEPROM after 3 consecutive attempts. DTC B1556 will clear when data read by BCM matches data written to EEPROM or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

If DTC B1556 is set, clear DTCs and cycle ignition. If DTC B1556 sets, replace BCM. See BODY CONTROL MODULE (BCM) under REMOVAL & INSTALLATION. Reprogram BCM. See PROGRAMMING . Perform BCM SYSTEM CHECK.

DTC B1558: BCM EEPROM CHECKSUM ERROR

When ignition switch is turned to RUN position, BCM adds the checksum of EEPROM block. DTC B1558 will set when running checksum does not match computed checksum. DTC B1558 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

If DTC B1558 is set, clear DTCs and cycle ignition. If DTC B1558 sets, replace BCM. See BODY CONTROL MODULE (BCM) under REMOVAL & INSTALLATION. Reprogram BCM. See PROGRAMMING . Perform BCM SYSTEM CHECK.

DTC B1970: EXTERIOR LIGHT POWER FAULT

BCM commands exterior lights on by energizing low beam and parking light relays. DTC B1970 will set when exterior lights have been commanded on and BCM detects a short to ground in Red/White wire between BCM and relays. When DTC B1970 is set, BCM will command exterior lights off, then attempt to turn exterior lights on until lights are no longer requested. DTC B1970 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. If DTC B1970 is a history code, problem may be intermittent. Wiggle wires while performing the following test.

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
2. Remove low beam relay from relay box located under instrument panel. (Scheme 1) Connect DVOM leads between low beam relay terminal No. 3 (Red/White wire) at relay box and ground. Connect scan tool. Select EXTERIOR LAMPS from light test menu in SPECIAL FUNCTIONS. While commanding exterior lights on and off, check voltage reading. Status should change as commanded, and battery voltage should exist when exterior lights are on. If voltage is as specified, go to next step. If voltage is not as specified, go to step 4).
3. Check for poor connection at BCM 32-pin connector C2, terminal B10 (Red/White wire). Check all BCM power and ground circuits. See WIRING DIAGRAMS. Using scan tool, clear codes. Check for codes. If DTC B1970 is set, go to step 5). If DTC B1970 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
4. Remove parking light relay from relay box located under instrument panel. (Scheme 1) Disconnect BCM 32-pin C2 connector. Using DVOM, check resistance between low beam relay terminal No. 3 (Red/White wire) at relay box and ground. If resistance is infinite, go to step 6). If resistance is not infinite, go to step 7).
5. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming). Perform BCM SYSTEM CHECK.
6. Leave DVOM connected as specified in step 4). While observing DVOM, wiggle wires between BCM and relay box. If DVOM indicates a short to ground, go to next step. If DVOM does not indicate a short to ground, go to step 3).
7. Repair short to ground in Red/White wire between BCM, parking light relay and low beam relay. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).

DTC B1971: INADVERTENT POWER FAULT

If interior lights are accidentally left on, a Delayed Interior Lighting (DIL) feature provides automatic shutoff. When ignition switch is in RUN position, BCM continuously keeps output to DIL relay active. When ignition switch is turned to OFF position, BCM will deactivate DIL relay output after 10 minutes. The 10-minute timeout period resets anytime BCM wakes up and any of the following states are detected

1. Illuminated Entry - A door is opened or closed; or driver door unlock message is received.
2. The trunk is opened or closed.
3. Interior lights are turned on.

When DIL relay is energized, power is supplied to interior lights and high side of interior light relay coil.

BCM continuously monitors output to DIL relay. DTC B1971 will set when output is commanded on or off, and short or open is detected for at least 2 seconds. When DTC B1971 is set, BCM will continue to command requested state of relay until it is achieved or no longer necessary. DTC B1971 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. If DTC B1971 is a history code, problem may be intermittent. Wiggle wires while performing the following test.

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
2. Connect scan tool. Select DELAY INTERIOR LIGHTS from light test menu in SPECIAL FUNCTIONS. While observing scan tool, command DIL relay on and off by pressing on and off buttons on scan tool. If status changes with commanded state, go to next step. If status does not change with commanded state, go to step 4).
3. Check for poor connection at BCM 32-pin connector C2 terminal C03 (Brown/Purple wire). Check all BCM power and ground circuits. See WIRING DIAGRAMS. Using scan tool, clear codes. Check for codes. If DTC B1971 is set, go to step 5). If DTC B1971 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
4. Disconnect multifunction relay module connector. (Scheme 1) Using DVOM, check resistance between multifunction relay module terminals No. 5 (Red wire) and No. 7 (Brown/Purple wire). If resistance is infinite, go to step 6). If resistance is not infinite, go to step 7).
5. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming). Perform BCM SYSTEM CHECK.
6. Replace multifunction relay module. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
7. Disconnect BCM 32-pin connector C2. Using DVOM, check resistance between multifunction relay module terminal No. 7 (Brown/Purple wire) and BCM connector C2, terminal C03 (Brown/Purple wire). If resistance is less than 2 ohms, go to next step. If resistance is not less than 2 ohms, go to step 9).
8. Move DVOM lead from multifunction relay module terminal No. 7 to ground. If resistance is infinite, go to step 10). If resistance is not infinite, go to step 11).
9. Repair open in Brown/Purple wire between BCM and multifunction relay module. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
10. Leave DVOM connected as specified in step 8). Switch DVOM to DC volts scale. Record voltage reading. Turn ignition switch to ON position. Record voltage reading. If both voltage readings are less than one volt, go to step 3). If both voltage readings are not less than one volt, go to step 12).
11. Repair short to ground in Brown/Purple wire between BCM and multifunction relay module. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
12. Repair short to battery in Brown/Purple wire between BCM and multifunction relay module. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).

DTC B1972: LOW POWER DRIVER FAULT

When ignition is turned to LOCK position, high power mode is activated for 15 minutes. After 15 minutes, high power mode is deactivated and low power driver output is turned on. Low power control output will supply 2 amps of current for up to 72 hours to the following components

1. Radio receiver.
2. Radio Interface Module (RIM).
3. Fuel tank filler door relay coil.
4. Rear compartment lid release relay coil.
5. Phone (dealer-installed).

DTC B1972 will set when low power control output is low for more than 300 milliseconds. When DTC B1972 is set, BCM will turn low power control output off until ignition state changes or BCM wakes-up. DTC B1972 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. If DTC B1972 is a history code, problem may be intermittent. Wiggle wires while performing the following test.

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
2. Disconnect BCM 24-pin C1 connector. Disconnect multifunction relay module connector. (Scheme 1) Disconnect all components on low power driver circuit (Red wire) between BCM and multifunction relay module. Using DVOM, check resistance between BCM connector C1, terminal B11 (Red wire) and ground. If resistance is infinite, go to next step. If resistance is not infinite, go to step 4).
3. Check for poor connection at BCM connector C1, terminal B11 (Red wire). Check all BCM power and ground circuits. See WIRING DIAGRAMS. Reinstall all disconnected components and connectors. Using scan tool, clear codes. Check for codes. If DTC B1972 is set, go to step 5). If DTC B1972 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
4. Disconnect C200B connector, located in instrument panel wiring harness-to-body wiring harness at lower left "A" pillar. Using DVOM, check resistance between BCM connector C1, terminal B11 (Red wire) and ground. If resistance is infinite, go to step 6). If resistance is not infinite, go to step 7).
5. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming). Perform BCM SYSTEM CHECK.
6. Repair short to ground in Red wire between multifunction relay module, radio and connector C200B. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
7. Repair short to ground in Red wire between connector C200B and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).

DTC B1973: HIGH POWER CONTROL FAULT

Battery guard relay supplies power to modules during controlled power usage. For 15 minutes after ignition is turned to LOCK position and BCM is awake, battery guard relay output coil is grounded. After 15 minutes, low power driver output is turned on.

DTC B1973 will set when BCM detects a short to battery in battery guard relay output circuit. When DTC B1973 is set, BCM will turn low power control output off if ignition is in LOCK position. DTC B1973 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. If DTC B1973 is a history code, problem may be intermittent. Wiggle wires while performing the following test.

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
2. Disconnect BCM 32-pin C2 connector. Disconnect multifunction relay module. (Scheme 1) Using DVOM, check voltage at BCM connector C2, terminal D01 (Brown/Blue wire). Turn ignition switch to ON position. Check voltage reading. If both voltage readings are less than one volt, go to next step. If both voltage readings are not less than one volt, go to step 4).
3. Check for poor connection at BCM connector C2, terminal D01 (Brown/Blue wire). Check all BCM power and ground circuits. See WIRING DIAGRAMS. Reinstall all disconnected components and connectors. Using scan tool, clear codes. Check for codes. If DTC B1973 is set, go to step 5). If DTC B1973 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
4. Repair short to battery in Brown/Blue wire between multifunction relay module and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
5. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming). Perform BCM SYSTEM CHECK.

DTC B1982: BATTERY VOLTAGE TOO HIGH

Battery voltage is supplied to BCM at 24-pin connector C1, terminal B03 (Red wire). BCM utilizes voltage to perform all BCM functions. BCM constantly measures this battery voltage signal. DTC B1982 will set when battery voltage measured is greater than 15.5 volts for 4 consecutive monitoring cycles. DTC B1982 will clear when battery voltage is less than 15 volts for 4 consecutive monitoring cycles or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. If DTC B1982 is set, check for overcharging condition in charging system. Ensure BCM power and ground connections are clean and tight. See WIRING DIAGRAMS .

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check) .
2. Connect scan tool to Data Link Connector (DLC). Select DATA. Start engine. If above 15 volts is displayed on scan tool, go to next step. If above 15 volts is not displayed on scan tool, go to step 4).
3. Locate and repair problem in charging system. See «GENERATOR & REGULATOR»(/cadillac/catera/i-1996-2001/remont/charging-system/#charging-system) article. Perform BCM SYSTEM CHECK.
4. Check all BCM power and ground circuits. See «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) . Using scan tool, clear codes. Check for codes. If DTC B1982 is set, go to next step. If DTC B1982 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check) .
5. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming) . Perform BCM SYSTEM CHECK.

DTC B1983: BATTERY VOLTAGE TOO LOW

Battery voltage is supplied to BCM at 24-pin connector C1, terminal B03 (Red wire). BCM utilizes voltage to perform all BCM functions. BCM constantly measures this battery voltage signal. DTC B1983 will set when voltage is less than 9 volts for 4 consecutive monitoring cycles. DTC B1983 will clear when battery voltage is greater than 9.5 volts for 4 consecutive monitoring cycles or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. Check battery condition, and replace if necessary. Ensure BCM ground connections are clean and tight. See WIRING DIAGRAMS .

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check) .
2. Connect scan tool to Data Link Connector (DLC). Select DATA. If less than 9 volts is displayed on scan tool, go to next step. If less than 9 volts is not displayed on scan tool, go to step 4).
3. Disconnect BCM 24-pin C1 connector. Check voltage at BCM connector C1, terminal B03 (Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, go to step 5).
4. Check for poor connection at BCM connector C1, terminal B03 (Red wire). Check for poor connection at BCM 32-pin connector C2, terminal C01 (Black wire). Using scan tool, clear codes. Check for codes. If DTC B1983 is set, go to step 6). If DTC B1983 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check) .
5. Repair high resistance or open in Red wire between BCM and power distribution fuse block (located in left front corner of engine compartment, attached to ECM housing, above battery). Perform procedures in «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check) .
6. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming) . Perform BCM SYSTEM CHECK.

DTC B2470: DAYTIME RUNNING LIGHTS FAULT

Daytime Running Lights (DRL) are commanded on and off by BCM through DRL relay. DRL are activated under one or all of the following conditions: When ignition switch is in ON position, twilight sentinel is not active, headlights and foglights are off, and transmission is not in Park. When DRL relay is energized, high beams are placed in a series circuit which provides lower illumination for DRL.

DTC B2470 will set when BCM detects an open or short circuit for 2 seconds. When DTC B2470 is set, BCM will continue to command state requested until it is achieved or changes. DTC B2470 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. If DTC B2470 is a history code, problem may be intermittent. Wiggle wires while performing the following test.

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
2. Connect scan tool. Select DAYTIME RUNNING LIGHTS from light test menu in SPECIAL FUNCTIONS. While observing scan tool, press on and off buttons on scan tool several times. If status changes and DRL operates with commanded state, go to next step. If status does not change or DRL does not operate with commanded state, go to step 4).
3. Check for poor connection at BCM 32-pin, connector C2, terminal C05 (Brown/Purple wire). Check all BCM power and ground circuits. See «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module). Ensure all connectors and components are connected. Using scan tool, clear codes. Check for codes. If DTC B2470 is set, go to step 12). If DTC B2470 is not set, see procedures in «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
4. Disconnect BCM 32-pin C2 connector. Check voltage at BCM connector C2, terminal C05 (Brown/Purple wire). If battery voltage exists, go to step 3). If battery voltage does not exist, go to next step.
5. Remove DRL relay. (Scheme 1) Using DVOM, check resistance between DRL relay terminal No. 1 (Brown/Purple wire) at relay box and BCM connector C2, terminal C05 (Brown/Purple wire). If resistance is less than 2 ohms, go to next step. If resistance is not less than 2 ohms, go to step 7).
6. Move DVOM lead from DRL relay terminal No. 1 (Brown/Purple wire) at relay box to ground. If resistance is infinite, go to step 8). If resistance is not infinite, go to step 9).
7. Repair open in Brown/Purple wire between DRL relay and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
8. Leaving DVOM connected as specified in step 6), switch DVOM to DC volts scale. Record voltage reading. Turn ignition switch to ON position. Record voltage reading. If both voltage readings are less than one volt, go to step 10). If both voltage readings are not less than one volt, go to step 11).
9. Repair short to ground in Brown/Purple wire between DRL relay and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
10. Replace DRL relay. Reinstall all connectors and components. Using scan tool, clear codes. Check for codes. If DTC B2470 is set, go to step 12). If DTC B2470 is not set, see procedures in «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
11. Repair short to battery in Brown/Purple wire between DRL relay and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
12. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming). Perform BCM SYSTEM CHECK.

DTC B2471: INTERIOR LIGHTS FAULT

Interior lights are commanded by BCM through an output to interior lights relay. When interior lights relay is energized, ground is provided for interior lights.

DTC B2471 will set when BCM detects an open or short in output circuit to interior lights relay. When DTC B2471 is set, BCM will continue to command state requested until it is achieved or changes. DTC B2471 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. If DTC B2471 is a history code, problem may be intermittent. Wiggle wires while performing the following test.

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
2. Connect scan tool. Select INTERIOR LIGHTS from light test menu in SPECIAL FUNCTIONS. While observing scan tool, press on and off buttons on scan tool several times. If status changes and interior lights operate with commanded state, go to next step. If status does not change or interior lights do not operate with commanded state, go to step 4).
3. Check for poor connection at BCM 32-pin, connector C2, terminal C13 (Brown/Purple wire). Check all BCM power and ground circuits. See «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module). Ensure all connectors and components are connected. Using scan tool, clear codes. Check for codes. If DTC B2471 is set, go to step 14). If DTC B2471 is not set, see procedures in «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
4. Select DELAY INTERIOR LIGHTS from light test menu in SPECIAL FUNCTIONS. Press on button on scan tool to command delay interior lights on. Check voltage at BCM 32-pin, connector C2, terminal C13 (Brown/Purple wire). If battery voltage exists, go to step 3). If battery voltage does not exist, go to next step.
5. Disconnect multifunction relay module connector. (Scheme 1) Check voltage at multifunction relay module connector terminal No. 5 (Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, go to step 7).
6. Disconnect BCM 32-pin C2 connector. Using DVOM, check resistance between BCM connector C2, terminal C13 (Brown/Purple wire) and multifunction relay module terminal No. 9 (Brown/Purple wire). If resistance is less than 2 ohms, go to step 8). If resistance is not less than 2 ohms, go to step 9).
7. Repair open in Red wire between multifunction relay module and instrument panel fuse block.
8. Move DVOM lead from multifunction relay module terminal No. 9 (Brown/Purple wire) to ground. If resistance is infinite, go to step 10). If resistance is not infinite, go to step 11).
9. Repair open in Brown/Purple wire between multifunction relay module and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
10. Leaving DVOM connected as specified in step 8), switch DVOM to DC volts scale. Record voltage reading. Turn ignition switch to ON position. Record voltage reading. If both voltage readings are less than one volt, go to step 12). If both voltage readings are not less than one volt, go to step 13).
11. Repair short to ground in Brown/Purple wire between multifunction relay module and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
12. Replace multifunction relay module. Reinstall all connectors and components. Using scan tool, clear codes. Check for codes. If DTC B2471 is set, go to step 14). If DTC B2471 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
13. Repair short to battery in Brown/Purple wire between multifunction relay module and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
14. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming). Perform BCM SYSTEM CHECK.

DTC B2472: LOW BEAM OUTPUT FAULT

Low beams are commanded by BCM by supplying power and ground to low beam relay. BCM continuously monitors output to low beam relay when exterior lights power is active and DTC B1970 is not set as current.

DTC B2472 will set when headlight switch is not active and BCM detects a short to ground or open in output circuit to low beam relay for at least 3 seconds. A short to ground in Brown/Red wire between low beam relay and BCM may cause low beams to illuminate at all times when ignition switch is in ON or RUN position and headlight switch is off. When DTC B2472 is set, BCM will continue to command state requested until it is achieved or changes. DTC B2472 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. If DTC B2472 is a history code, problem may be intermittent. Wiggle wires while performing the following test.

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
2. Connect scan tool. Select LOW BEAMS from light test menu in SPECIAL FUNCTIONS. While observing scan tool, press on and off buttons on scan tool several times. If status changes and low beam lights operate with commanded state, go to next step. If status does not change or low beam lights do not operate with commanded state, go to step 4).
3. Check for poor connection at BCM 32-pin, connector C2, terminal C09 (Brown/Red wire). Check all BCM power and ground circuits. See «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module). Ensure all connectors and components are connected. Using scan tool, clear codes. Check for codes. If DTC B2472 is set, go to step 9). If DTC B2472 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
4. Remove low beam relay. (Scheme 1) Disconnect BCM 32-pin C2 connector. Using DVOM, check resistance between BCM connector C2, terminal C09 (Brown/Red wire) and low beam relay terminal No. 1 (Brown/Red wire) at relay box. If resistance is less than 2 ohms, go to step 5). If resistance is not less than 2 ohms, go to step 6).
5. Move DVOM lead from low beam relay terminal No. 1 (Brown/Red wire) to ground. If resistance is infinite, go to step 7). If resistance is not infinite, go to step 8).
6. Repair open in Brown/Red wire between low beam relay and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
7. Replace low beam relay. Reinstall all connectors and components. Using scan tool, clear codes. Check for codes. If DTC B2472 is set, go to step 9). If DTC B2472 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
8. Repair short to ground in Brown/Red wire between low beam relay and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
9. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming). Perform BCM SYSTEM CHECK.

DTC B2473: HIGH BEAM FAULT

When BCM receives an input to turn high beam lights on, BCM grounds both headlight (high beam) relays. DTC B2473 will set when BCM detects a short to ground or open in White wire between BCM and headlight (high beam) relay. A short to ground in White wire may cause high beam indicator and right high beam headlight to illuminate. When DTC B2473 is set, BCM will continue to command state requested until it is achieved or changes. DTC B2473 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. If DTC B2473 is a history code, problem may be intermittent. Wiggle wires while performing the following test.

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check) .
2. Connect scan tool. Select HIGH BEAMS from light test menu in SPECIAL FUNCTIONS. While observing scan tool, press on and off buttons on scan tool several times. If status changes and high beam lights operate with commanded state, go to next step. If status does not change or high beam lights do not operate with commanded state, go to step 4).
3. Check for poor connection at BCM 32-pin, connector C2, terminal C08 (White wire). Check all BCM power and ground circuits. See «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) . Ensure all connectors and components are connected. Using scan tool, clear codes. Check for codes. If DTC B2473 is set, go to step 5). If DTC B2473 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check) .
4. Disconnect BCM 32-pin C2 connector. Disconnect C200B connector located in instrument panel wiring harness-to-body wiring harness at lower left "A" pillar. Using DVOM, check resistance between BCM connector C2, terminal C08 (White wire) and C200B connector terminal No. 58 (White wire). If resistance is less than 2 ohms, go to step 6). If resistance is not less than 2 ohms, go to step 7).
5. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming) . Perform BCM SYSTEM CHECK.
6. Move DVOM lead from C200B connector terminal No. 58 (White wire) to ground. If resistance is infinite, go to step 3). If resistance is not infinite, go to step 8).
7. Repair open in White wire between headlight (high beam) relay and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check) .
8. Repair short to ground in White wire between headlight (high beam) relay and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check) .

DTC B2476: PARKING LIGHTS OUTPUT FAULT

When BCM receives an input to turn parking lights on, BCM supplies power and ground to parking light relay. BCM continuously monitors output to parking light relay when exterior lights power is active and DTC B1970 is not set as current.

DTC B2476 will set when headlight switch is not active and BCM detects a short to ground or open in output circuit to parking light relay for at least 3 seconds. A short to ground in output circuit may cause low beams to illuminate at all times when ignition switch is in ON or RUN position and headlight switch is off. When DTC B2476 is set, BCM will continue to command state requested until it is achieved or changes. DTC B2476 will clear when conditions for fault no longer exist or when scan tool is used. A history DTC will clear after 50 consecutive ignition cycles if conditions for fault no longer exist.

Note. If DTC B2476 is a history code, problem may be intermittent. Wiggle wires while performing the following test.

1. If BCM system check was performed, go to next step. If BCM system check was not performed, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
2. Connect scan tool. Select PARK LAMPS from light test menu in SPECIAL FUNCTIONS. While observing scan tool, press on and off buttons on scan tool several times. If status changes and parking lights operate with commanded state, go to next step. If status does not change or parking lights do not operate with commanded state, go to step 4).
3. Check for poor connection at BCM 32-pin, connector C2, terminal C12 (Brown/White wire). Check all BCM power and ground circuits. See «WIRING DIAGRAMS»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module). Ensure all connectors and components are connected. Using scan tool, clear codes. Check for codes. If DTC B2476 is set, go to step 9). If DTC B2472 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
4. Remove parking light relay. (Scheme 1) Disconnect BCM 32-pin C2 connector. Using DVOM, check resistance between BCM connector C2, terminal C12 (Brown/White wire) and parking light relay terminal No. 1 (Brown/White wire) at relay box. If resistance is less than 2 ohms, go to step 5). If resistance is not less than 2 ohms, go to step 6).
5. Move DVOM lead from parking light relay terminal No. 1 (Brown/White wire) to ground. If resistance is infinite, go to step 7). If resistance is not infinite, go to step 8).
6. Repair open in Brown/White wire between parking light relay and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
7. Replace parking light relay. Reinstall all connectors and components. Using scan tool, clear codes. Check for codes. If DTC B2476 is set, go to step 9). If DTC B2476 is not set, go to «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
8. Repair short to ground in Brown/White wire between parking light relay and BCM. Perform «BCM SYSTEM CHECK»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__bcm-system-check).
9. Replace BCM. See «BODY CONTROL MODULE (BCM)»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module) under REMOVAL & INSTALLATION. Reprogram BCM. See «PROGRAMMING»(/cadillac/catera/i-1996-2001/remont/body-cab-control-systems/#body-control-module__programming). Perform BCM SYSTEM CHECK.

REMOVAL & INSTALLATION

Note. Electrical connectors are designed to fit in only one way, and have indexing tabs and slots on both halves of connector. DO NOT force connector into place.

Turn ignition switch to OFF position. Disconnect negative battery cable. Remove right hinge pillar trim finish panel. Gently separate retainer from BCM, and slide end of BCM out of guides. (Scheme 2) Remove BCM. Disconnect electrical connectors. Installation

Reconnect harness connectors and reinstall BCM. BCM is fully installed when retainer clips over edge of BCM. Reinstall right hinge pillar trim finish panel. Reconnect negative battery cable. Reprogram BCM. See PROGRAMMING .

Scheme 2

Data Link Connector (DLC) Wiring Diagram. Scheme 3

See also:
• GENERATOR & REGULATOR
• COMPUTER RELEARN PROCEDURES
• BCM DTC DEFINITIONS
• PROGRAMMING
• BCM SYSTEM CHECK