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Body Control Modules: Diagnosis Chevrolet Malibu V facelift

Communication Devices 9 illustrations ~17175 words

TROUBLE SHOOTING

Note. To diagnose indicators and gauges, see ANALOG INSTRUMENT PANELS - MALIBU article.

PRELIMINARY INSPECTION

Verify customer complaint by operating suspected system. Visually inspect for obvious signs of mechanical and electrical damage. Check BFC/BATT fuse "F" (10-amp) and IPC/BFC ACC fuse "J" (10-amp) in left instrument panel junction block. (Scheme 1) Left instrument panel junction block is located on left end of instrument panel. Check INT LPS fuse "F" (10-amp) and CRUISE fuse "D" (10-amp) in right instrument panel junction block. (Scheme 2) Right instrument panel junction block is located on right end of instrument panel. Check A/C BFC fuse No. 37 (10-amp) in underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. See WIRING DIAGRAMS.

Inspect 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. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. If no fault is found, perform self-diagnostics. See SELF-DIAGNOSTIC SYSTEM.

Scheme 1

Scheme 1: PRELIMINARY INSPECTION
Scheme 1: PRELIMINARY INSPECTION

Scheme 2

Scheme 2
Scheme 2

Scheme 3

Scheme 3
Scheme 3

SELF-DIAGNOSTIC SYSTEM

Begin diagnosis of body control system by performing appropriate diagnostic system check for system in which customer concern is apparent. See DIAGNOSTIC SYSTEM CHECK table.

SystemPerform Test
AirbagAIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK
Anti-Lock BrakeANTI-LOCK BRAKE SYSTEM DIAGNOSTIC SYSTEM CHECK
Audible WarningsAUDIBLE WARNINGS DIAGNOSTIC SYSTEM CHECK
AudioAUDIO SYSTEM DIAGNOSTIC SYSTEM CHECK
Automatic TransmissionAUTOMATIC TRANSMISSION DIAGNOSTIC SYSTEM CHECK
Body Rear EndBODY REAR END DIAGNOSTIC SYSTEM CHECK
Cruise ControlCRUISE CONTROL DIAGNOSTIC SYSTEM CHECK
Door SystemsDOOR SYSTEMS DIAGNOSTIC SYSTEM CHECK
Engine CoolingENGINE COOLING DIAGNOSTIC SYSTEM CHECK
Engine ElectricalENGINE ELECTRICAL DIAGNOSTIC SYSTEM CHECK
Heating Ventilation Air ConditioningHEATING VENTILATION AIR CONDITIONING DIAGNOSTIC SYSTEM CHECK
HornsHORNS DIAGNOSTIC SYSTEM CHECK
Hydraulic BrakesHYDRAULIC BRAKES DIAGNOSTIC SYSTEM CHECK
Instrument ClusterINSTRUMENT CLUSTER DIAGNOSTIC SYSTEM CHECK
LightingLIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK
Powertrain ControlPOWERTRAIN CONTROL MODULE DIAGNOSTIC SYSTEM CHECK
Remote Keyless EntryREMOTE KEYLESS ENTRY SYSTEM DIAGNOSTIC SYSTEM CHECK
Theft DeterrentTHEFT DETERRENT SYSTEM DIAGNOSTIC SYSTEM CHECK

DIAGNOSTIC SYSTEM CHECK

AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, see «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM). If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for BCM. If scan tool does not display any BCM DTCs which begin with a "U", go to next step. If scan tool displays any BCM DTCs which begin with a "U", perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).
  4. Using scan tool, attempt to establish communication with Sensing and Diagnostic Module (SDM). If scan tool communicates with SDM, go to next step. If scan tool does not communicate with SDM, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  5. Select Supplemental Inflatable Restraint (SIR) DISPLAY DTCS function on scan tool. If scan tool displays any SIR DTCs, go to next step. If scan tool does not display any SIR DTCs, repair by symptom. For information on air bag DIAGNOSIS & TESTING or DISPOSAL PROCEDURES, see AIR BAG SERVICE & REPAIR MANUAL, DOMESTIC & IMPORTED MODELS.
  6. If scan tool displays any SIR DTCs which begin with a "U", go to next step. If scan tool does not display any SIR DTCs which begin with a "U", go to next step.
  7. If scan tool displays DTC B1000, perform «DTC B1000: BODY CONTROL MODULE MALFUNCTION»(ref-99721-S25696274412001073100000) under DIAGNOSTIC TESTS. If scan tool does not display DTC B1000, repair as necessary. For information on air bag DIAGNOSIS & TESTING or DISPOSAL PROCEDURES, see AIR BAG SERVICE & REPAIR MANUAL, DOMESTIC & IMPORTED MODELS.

Scheme 4

Scheme 4
Scheme 4

ANTI-LOCK BRAKE SYSTEM DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, see «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM), Electronic Brake Control Module (EBCM) and Powertrain Control Module (PCM). If scan tool communicates with BCM, EBCM and PCM, go to next step. If scan tool does not communicate with BCM, EBCM and PCM, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for BCM, EBCM and PCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom. See appropriate ANTI-LOCK article in BRAKES.
  4. If scan tool displays any DTCs which begin with a "U", see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  5. If scan tool displays DTC B1000, perform «DTC B1000: BODY CONTROL MODULE MALFUNCTION»(ref-99721-S25696274412001073100000) under DIAGNOSTIC TESTS. If scan tool does not display DTC B1000, go to next step.
  6. If scan tool displays DTC P0560 or P0620, go to GENERATORS & REGULATORS - "J", "N" & "W" BODIES article in STARTING & CHARGING SYSTEMS. If scan tool does not display DTC P0560 or P0620, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).

AUDIBLE WARNINGS DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, see «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM). If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for BCM. If scan tool displays any BCM DTCs, go to next step. If scan tool does not display any BCM DTCs, repair by symptom. See ANALOG INSTRUMENT PANELS - MALIBU article.
  4. If scan tool displays DTCs U1000-U1305, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display DTCs U1000-U1305, go to next step.
  5. If scan tool displays DTCs B1000, B1369, B1374 or B1379, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display DTCs B1000, B1369, B1374 or B1379, go to next step.
  6. If scan tool displays DTCs P0560 or P0620, go to GENERATORS & REGULATORS - "J", "N" & "W" BODIES article in STARTING & CHARGING SYSTEMS. If scan tool does not display DTC P0560 or P0620, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).

AUDIO SYSTEM DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, see «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with radio. If scan tool communicates with radio, go to next step. If scan tool does not communicate with radio, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for radio. If scan tool displays any radio DTCs, go to next step. If scan tool does not display any radio DTCs, repair audio system by symptom as necessary.
  4. If scan tool displays any DTCs which begin with a "U", see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  5. If scan tool displays DTC B1000, B1369, B1374 or B1379, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display DTC B1000, B1369, B1374 or B1379, go to next step.
  6. If scan tool displays DTC B1001 or B1780, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display DTC B1001 or B1780, go to next step.
  7. If scan tool displays DTC B1327, no repair is necessary. If scan tool does not display DTC B1327, repair audio system by symptom as necessary.

AUTOMATIC TRANSMISSION DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. If Malfunction Indicator Light (MIL) is illuminated, go to next step. If MIL is not illuminated, repair as necessary.
  3. Using scan tool, attempt to communicate with Powertrain Control Module (PCM). If scan tool communicates with PCM, go to next step. If scan tool does not communicate with PCM, perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  4. Select DISPLAY DTCS function on scan tool for PCM. If scan tool displays any DTCs, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display any DTCs, repair by symptom. See appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS.

BODY REAR END DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM). If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for BCM. If scan tool displays any BCM DTCs, go to next step. If scan tool does not display any BCM DTCs, repair by symptom as necessary.
  4. If scan tool displays any DTCs which begin with a "U", see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  5. Perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).

CRUISE CONTROL DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Powertrain Control Module (PCM). If scan tool communicates with PCM, go to next step. If scan tool does not communicate with PCM, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for PCM. If scan tool does not display any cruise control DTCs, go to next step. If scan tool displays DTCs P1554 or P1585, see appropriate CRUISE CONTROL SYSTEMS article. If scan tool displays DTCs P0502 or P0503, see HYDRA-MATIC 4T40-E & 4T45-E ELECTRONIC CONTROLS - EXCEPT SATURN "L" SERIES V6 article in AUTOMATIC TRANSMISSIONS.
  4. If scan tool displays any DTCs which begin with a "U", see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", repair by symptom as necessary.

DOOR SYSTEMS DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM). If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for BCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom as necessary.
  4. If scan tool displays any DTCs which begin with a "U", see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  5. If scan tool does not display DTCs B1000 or B1001, go to next step. If scan tool displays DTCs B1000 or B1001, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).
  6. If scan tool does not display DTCs B1369, B1374 or B1379, go to next step. If scan tool displays DTCs B1369, B1374 or B1379, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).
  7. If scan tool displays any DTCs which begin with a "P", see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If scan tool does not display any DTCs which begin with a "P", go to next step.
  8. If scan tool displays DTCs B3127, B3128, B3132, B3133, B3137 or B3138, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display DTCs B3127, B3128, B3132, B3133, B3137 or B3138, repair by symptom as necessary.

ENGINE COOLING DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Instrument Cluster Module (ICM) and Powertrain Control Module (PCM). If scan tool communicates with ICM and PCM, go to next step. If scan tool does not communicate with ICM and PCM, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for PCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom as necessary.
  4. If scan tool displays any DTCs which begin with a "U", see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).

ENGINE ELECTRICAL DIAGNOSTIC SYSTEM CHECK

  1. Test charging system. See appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. Repair as necessary. If charging system tests okay, go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  3. Turn ignition switch to ON position. Using scan tool, attempt to communicate with each module on class 2 serial data line. If scan tool communicates with all modules on class 2 serial data line, go to next step. If scan tool does not communicate with all modules on class 2 serial data line, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  4. Select DISPLAY DTCS function on scan tool for all modules on class 2 serial data line. Using scan tool, record all displayed DTCs. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom. See appropriate STARTING & CHARGING SYSTEMS article.
  5. If scan tool displays any DTCs which begin with a "U", see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool displays DTCs P0560 or P0620, go to GENERATORS & REGULATORS - "J", "N" & "W" BODIES article in STARTING & CHARGING SYSTEMS. If scan tool does not display any DTCs which begin with a "U", perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).

HEATING VENTILATION AIR CONDITIONING DIAGNOSTIC SYSTEM CHECK

  1. If you were directed here from a MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING, go to next step. If you were not directed here from a MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING, go to MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING to start diagnosis.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  3. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Powertrain Control Module (PCM). If scan tool communicates with PCM, go to next step. If scan tool does not communicate with PCM, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  4. Select DISPLAY DTCS function on scan tool for PCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom. See appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
  5. If scan tool displays any DTCs which begin with a "U", see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  6. If scan tool displays any DTCs which begin with a "P", see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If scan tool does not display any DTCs which begin with a "P", perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).

HORNS DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM). If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for BCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom as necessary.
  4. If scan tool displays any DTCs which begin with a "U", see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  5. If scan tool displays DTC B2752 or B2753, see STEERING COLUMN SWITCHES - MALIBU article. If scan tool does not display DTC B2752 or B2753, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).

HYDRAULIC BRAKES DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM) and Electronic Brake Control Module (EBCM). If scan tool communicates with BCM and EBCM, go to next step. If scan tool does not communicate with BCM and/or EBCM, see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for BCM and EBCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom. See appropriate article in BRAKES.
  4. If scan tool displays any DTCs which begin with a "U", see «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  5. If scan tool displays DTC B1000, perform «DTC B1000: BODY CONTROL MODULE MALFUNCTION»(ref-99721-S25696274412001073100000) under DIAGNOSTIC TESTS. If scan tool does not display DTC B1000, go to next step.
  6. Perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).

INSTRUMENT CLUSTER DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM), Electronic Brake Control Module (EBCM), Powertrain Control Module (PCM) and Sensing and Diagnostic Module (SDM). If scan tool communicates with BCM, EBCM, PCM and SDM, go to next step. If scan tool does not communicate with BCM, EBCM, PCM and/or SDM, perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for BCM, EBCM, PCM and SDM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom. See ANALOG INSTRUMENT PANELS - MALIBU article.
  4. If scan tool displays DTCs U1000-U1305, perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display DTCs U1000-U1305, go to next step.
  5. If scan tool displays DTC B1000, B1369, B1374 or B1379, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display DTC B1000, B1369, B1374 or B1379, go to next step.
  6. If scan tool displays DTCs U2000-U2007, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display DTCs U2000-U2007, go to next step.
  7. If scan tool displays DTCs P0560 or P0620, go to SELF-DIAGNOSTICS - 3.1L & 3.4L "N" & "W" BODIES EXCEPT LUMINA article in ENGINE PERFORMANCE. If scan tool does not display DTCs P0560 or P0620, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).

LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM). If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for BCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom as necessary. See appropriate article in WIRING DIAGRAMS.
  4. If scan tool displays any DTCs which begin with a "U", perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  5. Perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).

POWERTRAIN CONTROL MODULE DIAGNOSTIC SYSTEM CHECK

CAUTIONDO NOT perform this diagnostic system check unless a procedure directs you here. Search for applicable Technical Service Bulletins (TSB) before proceeding. Ensure battery is fully charged and battery cables are clean and tight.
  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM), Electronic Brake Control Module (EBCM), Powertrain Control Module (PCM) and Vehicle Theft Deterrent (VTD) module. If scan tool communicates with BCM, EBCM, PCM and VTD module, go to next step. If scan tool does not communicate with BCM, EBCM, PCM and/or VTD module, perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) 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/or idle, see appropriate BASIC DIAGNOSTIC PROCEDURES article in ENGINE PERFORMANCE.
  4. Select DISPLAY DTCS function on scan tool for BCM, EBCM, PCM and VTD module. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, go to step 9.
  5. Using scan tool, select CAPTURED INFO, in order to store the powertrain DTC information. Go to next step.
  6. If scan tool displays any DTCs which begin with a "U", perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  7. If scan tool displays DTC P0601 or P0602, see SELF-DIAGNOSTICS - 3.1L & 3.4L "N" & "W" BODIES EXCEPT LUMINA article in ENGINE PERFORMANCE. If scan tool does not display DTC P0601 or P0602, go to next step.
  8. If scan tool displays DTC P0560 or P0620, see SELF-DIAGNOSTICS - 3.1L & 3.4L "N" & "W" BODIES EXCEPT LUMINA article in ENGINE PERFORMANCE. If scan tool does not display DTC P0560 or P0620, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).
  9. If customer concern is with automatic transmission, see appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS. If customer concern is not with automatic transmission, go to next step.
  10. If customer concern is with Inspection/Maintenance (I/M) testing, see INSPECTION/MAINTENANCE PROCEDURES in SELF-DIAGNOSTICS - 3.1L & 3.4L "N" & "W" BODIES EXCEPT LUMINA article in ENGINE PERFORMANCE. If customer concern is not with Inspection/Maintenance (I/M) testing, go to next step.
  11. Repair by symptom. See appropriate TROUBLE SHOOTING - NO CODES article in ENGINE PERFORMANCE.

REMOTE KEYLESS ENTRY SYSTEM DIAGNOSTIC SYSTEM CHECK

  1. Vehicle can be equipped with 2 types of Remote Keyless Entry (RKE) systems. Open deck lid. If a Remote Control Door Lock Receiver (RCDLR) module is attached to bottom of rear window package shelf, go to next step. If a Remote Control Door Lock Receiver (RCDLR) module is not attached to bottom of rear window package shelf, go to step 8.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  3. Turn ignition switch to ON position. Using scan tool, select REMOTE FUNCTION ACTUATOR (RFA) and attempt to communicate with Body Control Module (BCM) and Remote Control Door Lock Receiver (RCDLR) module. If scan tool communicates with BCM and RCDLR, go to next step. If scan tool does not communicate with BCM and/or RCDLR, perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  4. Select DISPLAY DTCS function on scan tool for BCM and RCDLR. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom. See appropriate REMOTE KEYLESS ENTRY SYSTEMS article.
  5. If scan tool displays any DTCs which begin with a "U", perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  6. If scan tool displays DTC B1000 or B1001, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display DTC B1000 or B1001, go to next step.
  7. If scan tool displays any other DTCs, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display any other DTCs, repair by symptom. See POWER DOOR LOCKS & REMOTE KEYLESS ENTRY SYSTEMS - MALIBU article.
  8. Connect scan tool to Data Link Connector (DLC). DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  9. Turn ignition switch to ON position. Using scan tool, attempt to communicate with Body Control Module (BCM). If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  10. Select DISPLAY DTCS function on scan tool for BCM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair by symptom. See appropriate REMOTE KEYLESS ENTRY SYSTEMS article.
  11. If scan tool displays any DTCs which begin with a "U", perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  12. If scan tool displays DTC B1000 or B1001, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display DTC B1000 or B1001, go to next step.
  13. If scan tool displays any other DTCs, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display any other DTCs, repair by symptom. See appropriate REMOTE KEYLESS ENTRY SYSTEMS article.

THEFT DETERRENT SYSTEM DIAGNOSTIC SYSTEM CHECK

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, perform «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000) under SYSTEM TESTS.
  2. Turn ignition switch to ON position. Using scan tool, attempt to communicate 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, perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS.
  3. Select DISPLAY DTCS function on scan tool for BCM and PCM. If scan tool displays any DTCs for BCM or PCM, go to next step. If scan tool does not display any DTCs, repair by symptom. See ANTI-THEFT SYSTEMS - MALIBU article.
  4. If scan tool displays any DTCs which begin with a "U", perform «TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-99721-S19557280652001073100000) under SYSTEM TESTS. If scan tool does not display any DTCs which begin with a "U", go to next step.
  5. If scan tool displays DTCs P0601-P0607, P1600, P1621 or P1627, see SELF-DIAGNOSTICS - 3.1L & 3.4L "N" & "W" BODIES EXCEPT LUMINA article in ENGINE PERFORMANCE. If scan tool does not display DTCs P0601-P0607, P1600, P1621 or P1627, go to next step.
  6. If scan tool displays DTCs B1000, B1004, B1007 or B1009, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). If scan tool does not display DTCs B1000, B1004, B1007 or B1009, go to next step.
  7. If scan tool displays DTCs P0560 or P0620, see SELF-DIAGNOSTICS - 3.1L & 3.4L "N" & "W" BODIES EXCEPT LUMINA article in ENGINE PERFORMANCE. If scan tool does not display DTCs P0560 or P0620, perform appropriate test. See ANTI-THEFT SYSTEMS - MALIBU article.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DTCDescriptionPerform Test
B0016Right Front Passenger Frontal Deployment Loop Resistance Low(1)
B0017Right Front Passenger Frontal Deployment Loop Open(1)
B0018Right Front Passenger Frontal Deployment Loop Short To Ground Or Voltage Out Of Range(1)
B0022Left Front Driver Frontal Deployment Loop Resistance Low(1)
B0024Left Front Driver Frontal Deployment Loop Short To Ground Or Voltage Out Of Range(1)
B0026Left Front Driver Frontal Deployment Loop Open(1)
B0051Deployment Commanded(1)
B0053Deployment Commanded With Loop Malfunctions Present(1)
B1000Body Control Module MalfunctionDTC B1000
B1001Vehicle Option Configuration Error(2)
B1369Ignition 0 FaultDTC B1369
B1374Ignition 1 FaultDTC B1374
B1379Ignition 3 FaultDTC B1379
B1780Audio System Theft Lock EnabledDTC B1780
B2532Front Foglight Relay Output Short To Ground Or OpenDTC B2532
B2533Front Foglight Relay Output Short To VoltageDTC B2533
B2558Interior Light Control Output Short To VoltageDTC B2558
B2575Headlight Request/Feedback MismatchDTC B2575
B2577Headlight Control Circuit LowDTC B2577
B2578Headlight Relay Output Short To VoltageDTC B2578
B2585Parking Light System FaultDTC B2585
B2587Parking Light Relay Output Short To Ground Or OpenDTC B2587
B2588Parking Light Relay Output Short To VoltageDTC B2588
B2600Daytime Running Lights ErrorDTC B2600
B2601Daytime Running Lights Remain On Or Short To GroundDTC B2601
B2602Daytime Running Lights Relay Control Short To GroundDTC B2602
B2603Daytime Running Lights Relay Control Short To VoltageDTC B2603
B2647Ambient Light Sensor Circuit LowDTC B2647
B2648Ambient Light Sensor Circuit HighDTC B2648
B2752Horn Relay Coil Circuit Low(3)
B2753Horn Relay Coil Circuit High(3)
B2947Security System Sensor Power Circuit Low(4)
B2948Security System Sensor Power Circuit High(4)
B2957Security System Sensor Data Circuit Low(4)
B2958Security System Sensor Data Circuit High(4)
B2960Security System Sensor Data Incorrect But Valid(4)
B2965Key In Ignition Fault(3)
B3031Security System Controller In Learn Mode(4)
B3033Security System Indicates Tamper(4)
B3127Left Front Door Only Unlock Circuit Low(5)
B3128Left Front Door Only Unlock Circuit High(5)
B3132All Door Unlock Circuit Low(5)
B3133All Door Unlock Circuit High(5)
B3137All Door Lock Circuit Low(5)
B3138All Door Lock Circuit High(5)
B3267Deck Lid Relay Output Short To Ground Or Open(5)
B3268Deck Lid Relay Output Short To Voltage(5)
C0267Low Brake Fluid(6)
C1214Solenoid Valve Relay Contact Or Coil Circuit Open(6)
C1217Pump Motor Shorted To Ground(6)
C1218Pump Motor Circuit Shorted To Voltage(6)
C1221-C1235Wheel Speed Sensor Input Signal Is Zero(6)
C1236Low System Supply Voltage(6)
C1237High System Supply Voltage(6)
C1242 Or C1243Brake Pressure Modulator Valve Pump Motor Circuit Open(6)
C1254Abnormal Shutdown Detected(6)
C1255 Or C1256Electronic Brake Control Module Internal Malfunction(6)
C1261-C1268Commanded State Of Driver And Actual State Of Control Circuit Does Not Match(6)
C1295Brake Light Switch Circuit Open(6)
P0462Fuel Level Sensor Circuit Low Voltage(7)
P0463Fuel Level Sensor Circuit High Voltage(7)
P0480Cooling Fan Relay No. 1 Control Circuit(8)
P0481Cooling Fan Relay No. 2 Control Circuit(8)
P0530A/C Refrigerant Pressure Sensor Circuit(9)
P0560System Voltage(8)
P0620Generator Performance(8)
P1189Engine Oil Pressure Switch Circuit(7)
P1546A/C Relay Clutch Control Circuit(9)
P1554Cruise Control Feedback Circuit(10)
P1585Cruise Inhibit Output Circuit(10)
P1626Fuel Enable Malfunction(4)
P1630Vehicle Theft Deterrent Password Not Learned(4)
P1631Incorrect Password Detected From Vehicle Theft Deterrent System(4)
P1632Fuel Disable Password Sent To PCM From BCM(4)
PXXXXPowertrain Control Module Faults(8)
U1000 & U1255Class 2 Communication MalfunctionDTCS U1000 & U1255
U1001-U1254Loss Of XXX CommunicationsDTCS U1001-U1254
U1300Class 2 Serial Data Link LowDTC U1300
U1301Class 2 Serial Data Link HighDTC U1301
U2000-U2007Invalid Data Or Serial Peripheral Interface Serial Data In/Out Circuit Voltage Out Of RangeDTCS U2000-U2007
(1) For information on air bag DIAGNOSIS & TESTING or DISPOSAL PROCEDURES, see AIR BAG SERVICE & REPAIR MANUAL, DOMESTIC & IMPORTED MODELS. (2) If DTC B1001 is set for audio system, perform DTC B1001: VEHICLE OPTION CONFIGURATION ERROR (RADIO). If DTC B1001 is set for BCM, perform DTC B1001: VEHICLE OPTION CONFIGURATION ERROR (BODY CONTROL MODULE). (3) For horn system and ignition lock cylinder diagnostic trouble code descriptions and testing procedures, see STEERING COLUMN SWITCHES - MALIBU article. (4) For security system diagnostic trouble code descriptions and testing procedures, see ANTI-THEFT SYSTEMS - MALIBU article. (5) For door lock and deck lid release diagnostic trouble code descriptions and testing procedures, see POWER DOOR LOCKS & REMOTE KEYLESS ENTRY SYSTEMS - MALIBU article. (6) For brake system diagnostic trouble code descriptions and testing procedures, see appropriate ANTI-LOCK article in BRAKES. (7) For instrument cluster module diagnostic trouble code descriptions and testing procedures, see ANALOG INSTRUMENT PANELS - MALIBU article. (8) For powertrain control module diagnostic trouble code descriptions and testing procedures, see SELF-DIAGNOSTICS - 3.1L & 3.4L "N" & "W" BODIES EXCEPT LUMINA article in ENGINE PERFORMANCE. (9) For heating ventilation air conditioning diagnostic trouble code descriptions and testing procedures, see appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. (10) For cruise control system diagnostic trouble code descriptions and testing procedures, see CRUISE CONTROL SYSTEMS - MALIBU article.
(1)For information on air bag DIAGNOSIS & TESTING or DISPOSAL PROCEDURES, see AIR BAG SERVICE & REPAIR MANUAL, DOMESTIC & IMPORTED MODELS.
(2)If DTC B1001 is set for audio system, perform DTC B1001: VEHICLE OPTION CONFIGURATION ERROR (RADIO) . If DTC B1001 is set for BCM, perform DTC B1001: VEHICLE OPTION CONFIGURATION ERROR (BODY CONTROL MODULE) .
(3)For horn system and ignition lock cylinder diagnostic trouble code descriptions and testing procedures, see STEERING COLUMN SWITCHES - MALIBU article.
(4)For security system diagnostic trouble code descriptions and testing procedures, see ANTI-THEFT SYSTEMS - MALIBU article.
(5)For door lock and deck lid release diagnostic trouble code descriptions and testing procedures, see POWER DOOR LOCKS & REMOTE KEYLESS ENTRY SYSTEMS - MALIBU article.
(6)For brake system diagnostic trouble code descriptions and testing procedures, see appropriate ANTI-LOCK article in BRAKES.
(7)For instrument cluster module diagnostic trouble code descriptions and testing procedures, see ANALOG INSTRUMENT PANELS - MALIBU article.
(8)For powertrain control module diagnostic trouble code descriptions and testing procedures, see SELF-DIAGNOSTICS - 3.1L & 3.4L "N" & "W" BODIES EXCEPT LUMINA article in ENGINE PERFORMANCE.
(9)For heating ventilation air conditioning diagnostic trouble code descriptions and testing procedures, see appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
(10)For cruise control system diagnostic trouble code descriptions and testing procedures, see CRUISE CONTROL SYSTEMS - MALIBU article.

DIAGNOSTIC TROUBLE CODE INDEX

Testing

Select DISPLAY DTCS function on scan tool for BCM. If DTC B1000 is not set as a current DTC, see DIAGNOSTIC AIDS . If DTC B1000 is set as a current DTC, replace and program BCM. See BODY CONTROL MODULE under REMOVAL & INSTALLATION.

Diagnostic Aids

DTC B1000 may be stored as a history DTC without affecting operation of the module. DO NOT replace module if DTC B1000 is stored only as a history DTC, and not as a current DTC. Replace module only if DTC B1000 is stored as a history and current DTC.

  1. Perform «AUDIO SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S27127661352001080100000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Program radio. See «RADIO»(ref-99721-S11657015612001081400000) under PROGRAMMING. Cycle ignition switch to OFF position, then to ON position. If DTC B1001 resets, go to next step. If DTC B1001 does not reset, repair is complete.
  3. Replace and program radio. See «RADIO»(ref-99721-S08356636882001081400000) under REMOVAL & INSTALLATION.

Program BCM. See BODY CONTROL MODULE (BCM) under PROGRAMMING.

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Select BCM DATA INPUTS list. If IGNITION 0 INPUT does not display ACTIVE, go to next step. If IGNITION 0 INPUT displays ACTIVE, go to «DIAGNOSTIC AIDS»(ref-99721-S20204589142001073100000).
  2. Check IPC/BFC ACC fuse (10-amp) in left instrument panel junction block. If fuse is blown, go to next step. If fuse is okay, go to step 6.
  3. Connect a test light between IPC/BFC ACC fuse terminal cavities in left instrument panel junction block. Turn ignition switch to ON position. If test light illuminates, go to next step. If test light does not illuminate, go to «DIAGNOSTIC AIDS»(ref-99721-S20204589142001073100000).
  4. Turn ignition switch to OFF position. Disconnect BCM Gray 16-pin harness connector C1. (Scheme 5) BCM is located under right side of instrument panel. (Scheme 6) Turn ignition switch to ON position. If test light illuminates, go to next step. If test light does not illuminate, go to step 10.
  5. Turn ignition switch to OFF position. Disconnect instrument cluster Gray 24-pin harness connector. Turn ignition switch to ON position. If test light illuminates, go to step 8. If test light does not illuminate, go to step 11.
  6. Remove IPC/BFC ACC fuse (10-amp) from left instrument panel junction block. Turn ignition switch to ON position. Using a test light connected to ground, check for power at both IPC/BFC ACC fuse terminal cavities in left instrument panel junction block. If test light illuminates at one terminal, go to next step. If test light does not illuminate at either terminal, go to step 9.
  7. Check for open in Purple wire between left instrument panel junction block Brown 68-pin harness connector C1 terminal C9, BCM harness connector C1 terminal A8 and instrument cluster harness connector terminal B9. (Scheme 5)and (Scheme 8). See «WIRING DIAGRAMS»(ref-99721-S39142036022001073100000). If Purple wire is okay, go to step 12. If Purple wire is open, repair as necessary. After repair, go to step 14.
  8. Repair short to ground in Purple wire between left instrument panel junction block Brown 68-pin harness connector C1 terminal C9, BCM harness connector C1 terminal A8 and instrument cluster harness connector terminal B9. (Scheme 5)and (Scheme 8). See «WIRING DIAGRAMS»(ref-99721-S39142036022001073100000). After repair, go to step 14.
  9. Repair open in power feed circuit to IPC/BFC ACC fuse (10-amp) in left instrument panel junction block. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 14.
  10. Check BCM harness connector C1 for corroded or pushed out terminals. If no problem is found, go to step 12. If poor connection exists, repair as necessary. After repair, go to step 14.
  11. Check instrument cluster harness connector for corroded or pushed out terminals. If no problem is found, go to step 13. If poor connection exists, repair as necessary. After repair, go to step 14.
  12. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to step 14.
  13. Replace instrument cluster. See ANALOG INSTRUMENT PANELS - MALIBU article. After repair, go to next step.
  14. Reconnect all disconnected components and connectors. Clear DTCs. If DTC resets, go to step 1.

Scheme 5

Scheme 5
Scheme 5

Scheme 6

Scheme 6
Scheme 6

If only history DTC B1369 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Select BCM DATA INPUTS list. If IGNITION 1 INPUT does not display ACTIVE, go to next step. If IGNITION 1 INPUT displays ACTIVE, go to step 9.
  2. Remove and inspect A/C BFC fuse (10-amp) in underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. If fuse is blown, go to next step. If fuse is okay, go to step 5.
  3. Connect a test light between A/C BFC fuse terminal cavities in underhood junction block. Turn ignition switch to ON position. If test light illuminates, go to next step. If test light does not illuminate, go to «DIAGNOSTIC AIDS»(ref-99721-S20204589142001073100000).
  4. Turn ignition switch to OFF position. Disconnect BCM Gray 24-pin harness connector C2. (Scheme 5) BCM is located under right side of instrument panel. (Scheme 6) Turn ignition switch to ON position. If test light illuminates, go to step 7. If test light does not illuminate, go to step 9.
  5. Turn ignition switch to ON position. Using a test light connected to ground, check for power at both A/C BFC fuse terminal cavities in underhood junction block. If test light illuminates at one terminal, go to next step. If test light does not illuminate at either terminal, go to step 8.
  6. Turn ignition switch to OFF position. Disconnect underhood junction block Gray 68-pin harness connector C3. (Scheme 7) Using DVOM, check continuity of Pink wire between BCM harness connector C2 terminal B9 and underhood junction block harness connector C3 terminal C4. If continuity exists, go to step 10. If continuity does not exist, repair open in Pink wire. After repair, go to step 11.
  7. Repair short to ground in Pink wire between BCM harness connector C2 terminal B9 and underhood junction block Gray 68-pin harness connector C3 terminal C4. (Scheme 7) See «WIRING DIAGRAMS»(ref-99721-S39142036022001073100000). After repairs, go to step 11.
  8. Repair open in power feed circuit to A/C BFC fuse. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repairs, go to step 11.
  9. Check BCM harness connector C2 for corroded or pushed out terminals. (Scheme 5) If no problem is found, go to next step. If a poor connection exists, repair as necessary. After repair, go to step 11.
  10. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to step 11.
  11. Reconnect all disconnected components and connectors. Clear DTCs. If DTC resets, go to step 1.

Scheme 7

Scheme 7
Scheme 7

If only history DTC B1374 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Select BCM DATA INPUTS list. If IGNITION 3 INPUT does not display ACTIVE, go to next step. If IGNITION 3 INPUT displays active, go to «DIAGNOSTIC AIDS»(ref-99721-S04872588522001073100000).
  2. Remove and inspect CRUISE fuse (10-amp) in right instrument panel junction block. If fuse is blown, go to next step. If fuse is okay, go to step 6.
  3. Connect a test light between CRUISE fuse terminal cavities in right instrument panel junction block. Turn ignition switch to ON position. If test light illuminates, go to next step. If test light does not illuminate, go to «DIAGNOSTIC AIDS»(ref-99721-S16371903412001073100000).
  4. Turn ignition switch to OFF position. Disconnect BCM Gray 16-pin harness connector C1. (Scheme 5) BCM is located below right side of instrument panel. (Scheme 6) Turn ignition switch to ON position. If test light illuminates, go to next step. If test light does not illuminate, go to step 10.
  5. Turn ignition switch to OFF position. Disconnect cruise control module Black 10-pin harness connector. Cruise control module is located in right front corner of engine compartment. Turn ignition switch to ON position. If test light illuminates, go to step 8. If test light does not illuminate, go to step 11.
  6. Turn ignition switch to ON position. Using a test light connected to ground, check for power at both CRUISE fuse terminal cavities in right instrument panel junction block. If test light illuminates at one terminal, go to next step. If test light does not illuminate at either terminal, go to step 9.
  7. Turn ignition switch to OFF position. Disconnect right instrument panel junction block Tan 68-pin harness connector C1. Using DVOM, check continuity of Brown wire between BCM harness connector C1 terminal B8 and right instrument panel junction block harness connector C1 terminal C4. (Scheme 8) If continuity exists, go to step 12. If problem is found, repair open in Brown wire. After repair, go to step 14.
  8. Repair short to ground in Brown wire between BCM harness connector C1 terminal B8 and right instrument panel junction block Tan 68-pin harness connector C1 terminal C4. (Scheme 8) After repairs, go to step 14.
  9. Repair open in power feed circuit to CRUISE fuse. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 14.
  10. Check BCM harness connector C1 for corroded or pushed out terminals. (Scheme 5) If connection is okay, go to next step. If a poor connection exists, repair as necessary. After repair, go to step 14.
  11. Check for poor connection at cruise control module harness connector. If connection is okay, go to step 13. If a poor connection exists, repair as necessary. After repair, go to step 14.
  12. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to step 14.
  13. Replace cruise control module. See CRUISE CONTROL SYSTEMS - MALIBU article. After repair, go to next step.
  14. Reconnect all disconnected components and connectors. Clear DTCs. If DTC resets, go to step 1.

If only history DTC B1379 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

Scheme 8

Scheme 8: Diagnostic Aids
Scheme 8: Diagnostic Aids
  1. Perform «AUDIO SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S27127661352001080100000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, clear DTCs and radio theft information. Turn ignition switch to OFF position. Turn ignition switch to ON position. If DTC B1780 resets, go to next step. If DTC B1780 does not reset, repair is complete.
  3. Replace and program radio. See «RADIO»(ref-99721-S08356636882001081400000) under REMOVAL & INSTALLATION.
  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command foglight relay ON and OFF. If foglight relay does not turn on and off, go to next step. If foglight relay turns on and off, go to «DIAGNOSTIC AIDS»(ref-99721-S35410539152001073100000).
  3. Turn ignition switch to OFF position. Remove foglight relay from right instrument panel junction block. (Scheme 2) Turn ignition switch to ON position. Using a test light connected to ground, probe foglight relay cavity terminal No. 86. If test light illuminates, go to next step. If test light does not illuminate, go to step 10.
  4. Connect a test light between foglight relay cavity terminals No. 86 and 85. Using scan tool, command foglight relay ON and OFF. If test light does not turn on and off, go to next step. If test light turns on and off, go to step 8.
  5. If test light stays off, go to next step. If test light stays on, go to step 7.
  6. Check for open in Dark Green/White wire between right instrument panel junction block Tan 68-pin harness connector C1 terminal F3 and BCM harness connector C1 terminal A2. (Scheme 5)and (Scheme 8). If Dark Green/White wire is okay, go to step 9. If Dark Green/White wire is open, repair as necessary. After repair, go to step 13.
  7. Check for short to ground in Dark Green/White wire between right instrument panel junction block Tan 68-pin harness connector C1 terminal F3 and BCM harness connector C1 terminal A2. (Scheme 5)and (Scheme 8). If Dark Green/White wire is okay, go to step 9. If Dark Green/White wire is shorted to ground, repair as necessary. After repair, go to step 13.
  8. Check for poor connections or damaged terminals at foglight relay. If a poor connection exists, repair as necessary. After repair, go to step 13. If no problem is found, go to step 11.
  9. Check BCM harness connector C3 for corroded or pushed out terminals. (Scheme 5) If connection is okay, go to step 12. If a poor connection exists, repair as necessary. After repair, go to step 13.
  10. Repair power feed circuit to foglight relay. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 13.
  11. Replace foglight relay. Go to step 13.
  12. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  13. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

Foglights will only illuminate when parking lights or low beam headlights are on, high beam headlights are off and foglight switch is actuated. If only history DTC B2532 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command foglight relay ON and OFF. If foglight relay does not turn on and off, go to next step. If foglight relay turns on and off, go to «DIAGNOSTIC AIDS»(ref-99721-S25109366232001073100000).
  3. Turn ignition switch to OFF position. Remove foglight relay from right instrument panel junction block. (Scheme 2) Turn ignition switch to ON position. Move headlight switch to park or low beam position. Using a test light connected to ground, probe relay cavity terminal No. 86. If test light illuminates, go to next step. If test light does not illuminate, go to step 8.
  4. Connect a test light between fog light relay cavity terminals No. 86 and 85. Using scan tool, command foglight relay ON and OFF. If test light does not turn on and off, go to next step. If test light turns on and off, go to step 6.
  5. Check for short to voltage in Dark Green/White wire between right instrument panel junction block Tan 68-pin harness connector C1 terminal F3 and BCM harness connector C1 terminal A2. (Scheme 5)and (Scheme 8). If Dark Green/White wire is okay, go to step 7. If Dark Green/White wire is shorted to voltage, repair as necessary. After repair, go to step 11.
  6. Check for poor connections or damaged terminals at foglight relay. If a poor connection exists, repair as necessary. After repair, go to step 11. If no problem is found, go to step 9.
  7. Check BCM harness connector C3 for corroded or pushed out terminals. (Scheme 5) If connection is okay, go to step 10. If a poor connection exists, repair as necessary. After repair, go to step 11.
  8. Repair power feed circuit to foglight relay. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 11.
  9. Replace foglight relay. Go to step 11.
  10. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  11. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

Foglights will only illuminate when parking lights or low beam headlights are on, high beam headlights are off and foglight switch is actuated. If only history DTC B2533 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command courtesy lights ON and OFF. If courtesy lights do not turn on and off, go to next step. If courtesy lights turn on and off, go to «DIAGNOSTIC AIDS»(ref-99721-S25109366232001073100000).
  3. Turn ignition switch to OFF position. Disconnect Body Control Module (BCM) harness connectors. BCM is located under right side of instrument panel. (Scheme 6) Turn ignition switch to ON position. Check interior lights control circuit for short to power. See appropriate wiring diagram in ILLUMINATION/INTERIOR LIGHTS article in WIRING DIAGRAMS. If interior lights control circuit is okay, go to next step. If interior lights control circuit is shorted to power, repair as necessary. After repair, go to step 6.
  4. Check BCM harness connectors for corroded or pushed out terminals. (Scheme 5) If connections are okay, go to next step. If a poor connection exists, repair as necessary. After repair, go to step 6.
  5. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  6. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If only history DTC B2558 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test. After repairing fault, ignition switch must be cycled before interior lights will illuminate.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command ALC headlight relay ON and OFF. If ALC headlight relay does not turn on and off, go to next step. If ALC headlight relay turns on and off, go to step 5.
  3. Turn ignition switch to OFF position. Remove ALC headlight relay from underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. Turn ignition switch to ON position. Using a test light connected to ground, probe ALC headlight relay cavity terminal No. 85. If test light illuminates, go to next step. If test light does not illuminate, go to step 9.
  4. Connect a test light between ALC headlight relay cavity terminals No. 86 and 85. Using scan tool, command ALC relay ON and OFF. If test light turns on and off, go to step 7. If test light does not turn on and off, go to step 6.
  5. Check low and high beam headlight signal circuits for open or high resistance. See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article in WIRING DIAGRAMS. If low and high beam headlight signal circuits are okay, go to step 8. If low and/or high beam headlight signal circuits are open, repair as necessary. After repair, go to step 12.
  6. Check ALC headlight relay control circuit for open or high resistance. See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article in WIRING DIAGRAMS. If ALC headlight relay control circuit is okay, go to step 8. If ALC headlight relay control circuit is open, repair as necessary. After repair, go to step 12.
  7. Check for poor connections or damaged terminals at ALC headlight relay. If a poor connection exists, repair as necessary. After repair, go to step 12. If no problem is found, go to step 10.
  8. Check BCM harness connector terminals for poor connections or damaged terminals. BCM is located under right side of instrument panel. (Scheme 6) If a poor connection exists, repair as necessary. After repair, go to step 12. If no problem is found, go to step 11.
  9. Repair open in coil side battery voltage circuit of ALC headlight relay. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 12.
  10. Replace ALC relay. Go to step 12.
  11. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  12. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

Turn ignition switch to OFF position. Cover ambient light sensor for 15 seconds. Turn ignition switch to ON position. Low beam headlights should illuminate. If only history DTC B2575 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command ALC headlight relay ON and OFF. If relay does not turn on and off, go to next step. If relay turns on and off, go to «DIAGNOSTIC AIDS»(ref-99721-S20404636592001073100000).
  3. Turn ignition switch to OFF position. Remove ALC relay from underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. Turn ignition switch to ON position. Using a test light connected to ground, probe ALC headlight relay cavity terminal No. 85. If test light illuminates, go to next step. If test light does not illuminate, go to step 10.
  4. Connect a test light between ALC headlight relay cavity terminals No. 86 and 85. Using scan tool, command ALC headlight relay ON and OFF. If test light does not turn on and off, go to next step. If test light turns on and off, go to step 8.
  5. If test light stays off, go to next step. If test light stays on, go to step 7.
  6. Check ALC headlight relay control circuit for open or high resistance. See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article in WIRING DIAGRAMS. If ALC headlight relay control circuit is okay, go to step 9. If ALC headlight relay control circuit is open, repair as necessary. After repair, go to step 13.
  7. Check ALC headlight relay control circuit for short to ground. See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article in WIRING DIAGRAMS. If ALC headlight relay control circuit is okay, go to step 9. If ALC headlight relay control circuit is shorted to ground, repair as necessary. After repair, go to step 13.
  8. Check for poor connections or damaged terminals at ALC headlight relay. If a poor connection exists, repair as necessary. After repair, go to step 13. If no problem is found, go to step 11.
  9. Check BCM harness connector terminals for poor connections or damaged terminals. BCM is located under right side of instrument panel. (Scheme 6) If a poor connection exists, repair as necessary. After repair, go to step 13. If no problem is found, go to step 12.
  10. Repair open in coil side battery voltage circuit of ALC headlight relay. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 13.
  11. Replace ALC relay. Go to step 13.
  12. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  13. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If ALC headlight relay control circuit is open, ALC will be inoperative. If ALC headlight relay control circuit is shorted to ground, ALC will always be on with ignition switch in ON position. If only history DTC B2577 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command ALC headlight relay ON and OFF. If ALC headlight relay does not turn on and off, go to next step. If ALC headlight relay turns on and off, go to «DIAGNOSTIC AIDS»(ref-99721-S25645321522001073100000).
  3. Check ALC headlight relay control circuit for short to voltage. See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article in WIRING DIAGRAMS. If ALC headlight relay control circuit is okay, go to next step. If ALC headlight relay control circuit is shorted to voltage, repair as necessary. After repair, go to step 6.
  4. Check BCM harness connectors for poor connections or damaged terminals. BCM is located under right side of instrument panel. (Scheme 6) If a poor connection exists, repair as necessary. After repair, go to step 6. If no problem is found, go to next step.
  5. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  6. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If only history DTC B2578 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command ALC parking light relay ON and OFF. If ALC parking light relay does not turn on and off, go to next step. If ALC parking light relay turns on and off, go to step 5.
  3. Turn ignition switch to OFF position. Remove ALC parking light relay from underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. Turn ignition switch to ON position. Using a test light connected to ground, probe ALC parking light relay cavity terminal No. 85. If test light illuminates, go to next step. If test light does not illuminate, repair open between ALC parking light relay cavity terminal No. 85 and PARK LPS fuse (15-amp) in underhood junction block. See POWER DISTRIBUTION article in WIRING DIAGRAMS.
  4. Connect a test light between ALC parking light relay cavity terminals No. 86 and 85. Using scan tool, command ALC parking light relay ON and OFF. If test light does not turn on and off, go to step 6. If test light turns on and off, go to step 7.
  5. Check for open, high resistance or short to ground in Brown wire between ALC parking light relay cavity terminal No. 87 and parking lights. See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article. If Brown wire is okay, go to step 8. If Brown wire is not okay, repair as necessary. After repair, go to step 11.
  6. Check for open, high resistance or short to ground in White wire between underhood junction block Gray 68-pin harness connector C3 terminal B8 and BCM Gray 16-pin harness connector C1 terminal B1. (Scheme 5)and (Scheme 7). See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article. If White wire is okay, go to step 8. If White wire is not okay, repair as necessary. After repair, go to step 11.
  7. Check for poor connections or damaged terminals at ALC headlight relay. If a poor connection exists, repair as necessary. After repair, go to step 11. If no problem is found, go to step 9.
  8. Check BCM harness connectors for poor connections or damaged terminals. If a poor connection exists, repair as necessary. After repair, go to step 11. If no problem is found, go to step 10.
  9. Replace ALC parking light relay. Go to step 11.
  10. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  11. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If only history DTC B2585 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command ALC parking light relay ON and OFF. If parking light relay does not turn on and off, go to next step. If parking light relay turns on and off, go to «DIAGNOSTIC AIDS»(ref-99721-S10540789672001073100000).
  3. Turn ignition switch to OFF position. Ensure headlights are off. If parking lights are not illuminated, go to next step. If parking lights are illuminated, go to step 6.
  4. Remove ALC parking light relay from underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. Turn ignition switch to ON position. Using a test light connected to ground, probe ALC parking light relay cavity terminal No. 85. If test light illuminates, go to next step. If test light does not illuminate, go to step 10.
  5. Connect a test light between ALC parking light relay cavity terminals No. 86 and 85. Turn ignition switch to ON position. Using scan tool, command ALC parking light relay ON. If test light does not illuminate, go to step 7. If test light illuminates, go to step 8.
  6. Check for short to ground in White wire between underhood junction block Gray 68-pin harness connector C3 terminal B8 and BCM Gray 16-pin harness connector C1 terminal B1. (Scheme 5)and (Scheme 7). See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article. If White wire is okay, go to step 9. If White wire is not okay, repair as necessary. After repair, go to step 13.
  7. Check for open or high resistance in White wire between underhood junction block Gray 68-pin harness connector C3 terminal B8 and BCM Gray 16-pin harness connector C1 terminal B1. (Scheme 5)and (Scheme 7). See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article. If White wire is okay, go to step 9. If White wire is not okay, repair as necessary. After repair, go to step 13.
  8. Check for poor connections or damaged terminals at ALC parking light relay. If a poor connection exists, repair as necessary. After repair, go to step 13. If no problem is found, go to step 11.
  9. Check BCM harness connectors for poor connections or damaged terminals. If a poor connection exists, repair as necessary. After repair, go to step 13. If no problem is found, go to step 12.
  10. Repair open, high resistance or short to ground between ALC parking light relay cavity terminal No. 85 and PARK LPS fuse (15-amp) in underhood junction block. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 13.
  11. Replace ALC parking light relay. Go to step 13.
  12. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  13. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If only history DTC B2587 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command ALC parking light relay ON and OFF. If ALC parking light relay does not turn on and off, go to next step. If ALC parking light relay turns on and off, go to «DIAGNOSTIC AIDS»(ref-99721-S25112103822001073100000).
  3. Turn ignition switch to OFF position. Remove ALC parking light relay from underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. Turn ignition switch to ON position. Using a test light connected to ground, probe parking light relay cavity terminal No. 85. If test light illuminates, go to next step. If test light does not illuminate, go to step 6.
  4. Check for short to voltage in White wire between underhood junction block Gray 68-pin harness connector C3 terminal B8 and BCM Gray 16-pin harness connector C1 terminal B1. (Scheme 5)and (Scheme 7). See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article. If White wire is okay, go to next step. If White wire is not okay, repair as necessary. After repair, go to step 8.
  5. Check BCM harness connectors for poor connections or damaged terminals. If a poor connection exists, repair as necessary. After repair, go to step 8. If no problem is found, go to step 7.
  6. Repair open, high resistance or short to ground between ALC parking light relay cavity terminal No. 85 and PARK LPS fuse (15-amp) in underhood junction block. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 8.
  7. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  8. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If only history DTC B2588 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command Daytime Running Light (DRL) relay ON and OFF. If DRL relay does not turn on and off, go to next step. If DRL relay turns on and off, go to «DIAGNOSTIC AIDS»(ref-99721-S41843510532001073100000).
  3. Turn ignition switch to OFF position. Remove DRL relay from underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. Turn ignition switch to ON position. Using a test light connected to ground, probe DRL relay cavity terminal No. 85. If test light illuminates, go to next step. If test light does not illuminate, go to step 8.
  4. Connect test light between DRL relay cavity terminals No. 85 and 86. Using scan tool, command DRL relay ON. If test light does not illuminate, go to next step. If test light illuminates, go to step 6.
  5. Check for open or high resistance in Light Green/Black wire between underhood junction block Gray 68-pin harness connector C3 terminal B12 and BCM Gray 16-pin harness connector C1 terminal B5. (Scheme 5)and (Scheme 7). If Light Green/Black wire is okay, go to step 7. If Light Green/Black wire is not okay, repair as necessary. After repair, go to step 11.
  6. Check for poor connections or damaged terminals at DRL relay. If a poor connection exists, repair as necessary. After repair, go to step 11. If no problem is found, go to step 9.
  7. Check BCM harness connectors for poor connections or damaged terminals. If a poor connection exists, repair as necessary. After repair, go to step 11. If no problem is found, go to step 10.
  8. Repair open, high resistance or short to ground between DRL relay cavity terminal No. 85 and HTR A/C IGN fuse (10-amp) in underhood junction block. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 11.
  9. Replace DRL relay. Go to step 11.
  10. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  11. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

Check both headlights for proper operation. Check both HDLP fuses in underhood junction block. Diagnose all other Daytime Running Lights (DRL) DTCs before diagnosing DTC B2600. If only history DTC B2600 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command Daytime Running Light (DRL) relay ON and OFF. If DRL relay does not turn on and off, go to next step. If DRL relay turns on and off, go to step 9.
  3. Turn ignition switch to OFF position. Remove DRL relay from underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. Turn ignition switch to ON position. Using a test light connected to ground, probe DRL relay cavity terminal No. 85. If test light illuminates, go to next step. If test light does not illuminate, go to step 12.
  4. Connect a test light between DRL relay cavity terminals No. 86 and 85. Using scan tool, command DRL relay ON and OFF. If test light does not turn on and off, go to next step. If test light turns on and off, go to step 8.
  5. If test light stays off, go to next step. If test light stays on, go to step 7.
  6. Check for open or high resistance in Light Green/Black wire between underhood junction block Gray 68-pin harness connector C3 terminal B12 and BCM Gray 16-pin harness connector C1 terminal B5. (Scheme 5)and (Scheme 7). If Light Green/Black wire is okay, go to step 11. If Light Green/Black wire is not okay, repair as necessary. After repair, go to step 15.
  7. Check for short to ground in Light Green/Black wire between underhood junction block Gray 68-pin harness connector C3 terminal B12 and BCM Gray 16-pin harness connector C1 terminal B5. (Scheme 5)and (Scheme 7). If Light Green/Black wire is okay, go to step 11. If Light Green/Black wire is not okay, repair as necessary. After repair, go to step 15.
  8. Check for poor connections or damaged terminals at DRL relay. If a poor connection exists, repair as necessary. After repair, go to step 15. If no problem is found, go to step 13.
  9. Disconnect both headlight harness connectors. Disconnect headlight switch harness connector. Disconnect BCM harness connectors. BCM is located under right side of instrument panel. (Scheme 6) Turn ignition switch to ON position. Check for short to voltage in Dark Blue wire between low beam headlights, BCM and headlight switch. See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article. If Dark Blue wire is okay, go to next step. If Dark Blue wire is not okay, repair as necessary. After repair, go to step 15.
  10. Check for short to voltage in Pink wire between high beam headlights, BCM and headlight switch. See appropriate wiring diagram in HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article. If Pink wire is okay, go to next step. If Pink wire is not okay, repair as necessary. After repair, go to step 15.
  11. Check BCM harness connectors for poor connections or damaged terminals. If a poor connection exists, repair as necessary. After repair, go to step 15. If no problem is found, go to step 14.
  12. Repair open between DRL relay cavity terminal No. 85 and HTR A/C IGN fuse (10-amp) in underhood junction block. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 15.
  13. Replace DRL relay. Go to step 15.
  14. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  15. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If DTC B2601 and 2602 exist, check for short to ground in Light Green/Black wire between underhood junction block harness connector C3 terminal B12 and BCM harness connector C1 terminal B5. If only history DTC B2601 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, command Daytime Running Light (DRL) relay ON and OFF. If DRL relay does not turn on and off, go to next step. If DRL relay turns on and off, go to «DIAGNOSTIC AIDS»(ref-99721-S38102190912001073100000).
  3. Turn ignition switch to OFF position. Remove DRL relay from underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. Turn ignition switch to ON position. Using a test light connected to ground, probe DRL relay cavity terminal No. 85. If test light illuminates, go to next step. If test light does not illuminate, go to step 10.
  4. Connect a test light between DRL relay cavity terminals No. 86 and 85. Using scan tool, command DRL relay ON and OFF. If test light does not turn on and off, go to next step. If test light turns on and off, go to step 8.
  5. If test light stays off, go to next step. If test light stays on, go to step 7.
  6. Check for open or high resistance in Light Green/Black wire between underhood junction block Gray 68-pin harness connector C3 terminal B12 and BCM Gray 16-pin harness connector C1 terminal B5. (Scheme 5)and (Scheme 7). If Light Green/Black wire is okay, go to step 9. If Light Green/Black wire is not okay, repair as necessary. After repair, go to step 13.
  7. Check for short to ground in Light Green/Black wire between underhood junction block Gray 68-pin harness connector C3 terminal B12 and BCM Gray 16-pin harness connector C1 terminal B5. (Scheme 5)and (Scheme 7). If Light Green/Black wire is okay, go to step 9. If Light Green/Black wire is not okay, repair as necessary. After repair, go to step 13.
  8. Check for poor connections or damaged terminals at DRL relay. If a poor connection exists, repair as necessary. After repair, go to step 13. If no problem is found, go to step 11.
  9. Check BCM harness connectors for poor connections or damaged terminals. If a poor connection exists, repair as necessary. After repair, go to step 13. If no problem is found, go to step 12.
  10. Repair open, high resistance or short to ground between DRL relay cavity terminal No. 85 and HTR A/C IGN fuse (10-amp) in underhood junction block. See POWER DISTRIBUTION article in WIRING DIAGRAMS. After repair, go to step 13.
  11. Replace DRL relay. Go to step 13.
  12. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  13. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If DTC B2601 and 2602 exist, check for short to ground in Light Green/Black wire between underhood junction block harness connector C3 terminal B12 and BCM harness connector C1 terminal B5. If only history DTC B2602 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Turn ignition switch to OFF position. Remove DRL relay from underhood junction block. (Scheme 3) Underhood junction block is located in left side of engine compartment. Turn ignition switch to ON position. Using a test light connected to ground, probe DRL relay cavity terminal No. 85. If test light illuminates, go to next step. If test light does not illuminate, go to step 4.
  3. Turn ignition switch to OFF position. Disconnect BCM harness connectors. BCM is located under right side of instrument panel. (Scheme 6) Turn ignition switch to ON position. Check for short to voltage in Light Green/Black wire between underhood junction block Gray 68-pin harness connector C3 terminal B12 and BCM Gray 16-pin harness connector C1 terminal B5. (Scheme 5)and (Scheme 7). If Light Green/Black wire is okay, go to step 5. If Light Green/Black wire is not okay, repair as necessary. After repair, go to step 8.
  4. Check for poor connections or damaged terminals at DRL relay. If a poor connection exists, repair as necessary. After repair, go to step 8. If no problem is found, go to step 6.
  5. Check BCM harness connectors for poor connections or damaged terminals. If a poor connection exists, repair as necessary. After repair, go to step 8. If no problem is found, go to step 7.
  6. Replace DRL relay. Go to step 8.
  7. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  8. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If only history DTC B2603 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, select LAMP STATUS then PHOTOCELL VOLTAGE. If voltage is not.5-4.5 volts, go to next step. If voltage is.5-4.5 volts, go to «DIAGNOSTIC AIDS»(ref-99721-S30204994042001073100000).
  3. Turn ignition switch to OFF position. Disconnect ambient light sensor harness connector. Ambient light sensor is located on top of instrument panel trim pad. Turn ignition switch to ON position. Using scan tool, observe PHOTOCELL VOLTAGE. If voltage is.5 volt or less, go to next step. If voltage is more than.5 volt, go to step 5.
  4. Check for open or short to ground in Light Green/Black wire between BCM Gray 24-pin harness connector C2 terminal B2 and ambient light sensor terminal "A". BCM is located under right side of instrument panel. (Scheme 6) Check for open or short to ground in Yellow/Black wire between BCM harness connector C2 terminal A3 and ambient light sensor terminal "B". (Scheme 5) If circuits are okay, go to step 6. If open or short to ground exists, repair as necessary. After repair, go to step 10.
  5. Turn ignition switch to ON position. Check for short to voltage in Light Green/Black wire between BCM harness connector C2 terminal B2 and ambient light sensor terminal "A". Check for short to voltage in Yellow/Black wire between BCM harness connector C2 terminal A3 and ambient light sensor terminal "B". If circuits are okay, go to step 7. If short to voltage exists, repair as necessary. After repair, go to step 10.
  6. Check ambient light sensor harness connector for poor connections or damaged terminals. If no problem is found, go to step 8. If poor connection exists, repair as necessary. After repair, go to step 10.
  7. Check BCM harness connectors for poor connections or damaged terminals. If a poor connection exists, repair as necessary. After repair, go to step 10. If no problem is found, go to step 9.
  8. Replace ambient light sensor. Go to step 10.
  9. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  10. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If only history DTC B2647 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. Perform «LIGHTING SYSTEM DIAGNOSTIC SYSTEM CHECK»(ref-99721-S34020613362001081400000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, select LAMP STATUS then PHOTOCELL VOLTAGE. If voltage is not.5-4.5 volts, go to next step. If voltage is.5-4.5 volts, go to «DIAGNOSTIC AIDS»(ref-99721-S35136518502001073100000).
  3. Turn ignition switch to OFF position. Disconnect ambient light sensor harness connector. Ambient light sensor is located on top of instrument panel trim pad. Turn ignition switch to ON position. Using scan tool, observe PHOTOCELL VOLTAGE. If voltage is.5 volt or less, go to next step. If voltage is more than.5 volt, go to step 5.
  4. Check for open or short to ground in Light Green/Black wire between BCM Gray 24-pin harness connector C2 terminal B2 and ambient light sensor terminal "A". BCM is located under right side of instrument panel. (Scheme 6) Check for open or short to ground in Yellow/Black wire between BCM harness connector C2 terminal A3 and ambient light sensor terminal "B". (Scheme 5) If Light Breen/Black and Yellow/Black wires are okay, go to step 6. If open or short to ground exists, repair appropriate wire as necessary. After repair, go to step 10.
  5. Turn ignition switch to ON position. Check for short to voltage on Light Green/Black wire between BCM Gray 24-pin harness connector C2 terminal B2 and ambient light sensor terminal "A". BCM is located under right side of instrument panel. (Scheme 6) Check for short to voltage on Yellow/Black wire between BCM harness connector C2 terminal A3 and ambient light sensor terminal "B". If Light Breen/Black and Yellow/Black wires are okay, go to step 7. If short to voltage exists, repair appropriate wire as necessary. After repair, go to step 10.
  6. Check ambient light sensor harness connector for poor connections or damaged terminals. If no problem is found, go to step 8. If poor connection exists, repair as necessary. After repair, go to step 10.
  7. Check BCM harness connectors for poor connections or damaged terminals. If no problem is found, go to step 9. If connections are poor, repair as necessary. After repair, go to step 10.
  8. Replace ambient light sensor. Go to step 10.
  9. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  10. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

If only history DTC B2648 is set, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.

  1. If no history DTC in the range of U1001-U1254 are set, go to next step. If any history DTC in the range of U1001-U1254 are set, see «DTCS U1001-U1254: LOSS OF XXX COMMUNICATIONS»(ref-99721-S33487603632001073100000).
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, attempt to communicate with all control modules on class 2 serial data circuit. See DATA LINK CONNECTORS article in WIRING DIAGRAMS. If any module on class 2 serial data circuit does not communicate with scan tool, go to next step. If all modules on class 2 serial data circuit communicate with scan tool, go to step 12.
  3. Check for open, high resistance or short to ground in battery and ignition voltage circuits to module identified as not communicating. See POWER DISTRIBUTION article in WIRING DIAGRAMS. If battery and ignition voltage circuits of affected module are okay, go to next step. If battery and ignition voltage circuits of affected module are not okay, repair as necessary. After repair, go to step 8.
  4. Turn ignition switch to OFF position. Check for open or high resistance in ground circuit to module identified as not communicating. See GROUND DISTRIBUTION article in WIRING DIAGRAMS. If ground circuit of affected module is okay, go to next step. If ground circuit of affected module is not okay, repair as necessary. After repair, go to step 8.
  5. Check for open in class 2 serial data circuit for module that is not communicating. See DATA LINK CONNECTORS article in WIRING DIAGRAMS. If class 2 serial data circuit of affected module is okay, go to next step. If class 2 serial data circuit of affected module is not okay, repair as necessary. After repair, go to step 8.
  6. Check for poor connections or damaged terminals at battery and ignition voltage circuits, ground circuit and class 2 serial data circuit for module identified as not communicating. If no problem is found, go to next step. If a poor connection exists, repair as necessary. After repair, go to step 8.
  7. Replace module that is not communicating. See appropriate article for replacement and programming information. After repair, go to step 10.
  8. Turn ignition switch to ON position. Using scan tool, select DISPLAY DTCS for module identified as not communicating. If scan tool does not display any DTCs that do not begin with a "U", go to next step. If scan tool displays any DTCs that do not begin with a "U", perform appropriate diagnostic system check for affected system. See «DIAGNOSTIC SYSTEM CHECK»(ref-99721-S29406924942001080900000) table under SELF-DIAGNOSTIC SYSTEM.
  9. Using scan tool, clear DTCs. Go to next step.
  10. Using scan tool, select DISPLAY DTCS for module which had DTC U1000 or U1255 set as a current DTC. If scan tool does not display any DTCs that do not begin with a "U", go to next step. If scan tool displays any DTCs that do not begin with a "U", perform appropriate diagnostic system check for affected system. See «DIAGNOSTIC SYSTEM CHECK»(ref-99721-S29406924942001080900000) table under SELF-DIAGNOSTIC SYSTEM.
  11. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 1. If DTC does not reset, system is okay at this time.
  12. If no other DTCs were recorded for module which had DTC U1000 or U1255 set as a current DTC, go to next step. If any other DTCs were recorded for module which had DTC U1000 or U1255 set as a current DTC, perform appropriate diagnostic system check for affected system. See «DIAGNOSTIC SYSTEM CHECK»(ref-99721-S29406924942001080900000) table under SELF-DIAGNOSTIC SYSTEM.
  13. Clear DTCs. Turn ignition switch to OFF position. After 5 seconds has elapsed, turn ignition switch to ON position. Select DISPLAY DTCS. If scan tool displays DTC U1000 or U1255 as a current DTC, go to next step. If scan tool does not display DTC U1000 or U1255 as a current DTC, go to «DIAGNOSTIC AIDS»(ref-99721-S39117279142001082100000).
  14. Replace and program module which had DTC U1000 or U1255 set as a current DTC.

When a malfunction (such as an open fuse to a module) occurs while modules are communicating, a Loss Of XXX Communication DTC is set as current. When modules stop communicating (ignition off), current Loss Of XXX Communication DTC is cleared but history DTC remains. When modules begin communication again (ignition on), module not communicating will not be learned by other modules, causing DTC U1000 or U1255 to set as current DTC. If malfunction occurs when modules are not communicating, only DTC U1000 will set.

  1. Check for open, high resistance or short to ground in battery and ignition voltage circuits to module identified as not communicating. See POWER DISTRIBUTION article in WIRING DIAGRAMS. If battery and ignition voltage circuits of affected module are okay, go to next step. If battery and ignition voltage circuits of affected module are not okay, repair as necessary. After repair, go to step 6.
  2. Turn ignition switch to OFF position. Check for open or high resistance in ground circuit to module identified as not communicating. See GROUND DISTRIBUTION article in WIRING DIAGRAMS. If ground circuit of affected module is okay, go to next step. If ground circuit of affected module is not okay, repair as necessary. After repair, go to step 6.
  3. Check for poor connections or damaged terminals at battery and ignition voltage circuits, ground circuit and class 2 serial data circuit for module identified as not communicating. If no problem is found, go to next step. If a poor connection exists, repair as necessary. After repair, go to step 6.
  4. Check for open in class 2 serial data circuit for module that is not communicating. See DATA LINK CONNECTORS article in WIRING DIAGRAMS. If class 2 serial data circuit of affected module is okay, go to next step. If class 2 serial data circuit of affected module is not okay, repair as necessary. After repair, go to step 6.
  5. Replace module that is not communicating. See appropriate article for replacement and programming information. After repair, go to next step.
  6. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, select DISPLAY DTCS for module identified as not communicating. If scan tool does not display any DTCs that do not begin with a "U", go to next step. If scan tool displays any DTCs that do not begin with a "U", perform appropriate diagnostic system check for affected system. See «DIAGNOSTIC SYSTEM CHECK»(ref-99721-S29406924942001080900000) table under SELF-DIAGNOSTIC SYSTEM.
  7. Using scan tool, clear DTCs. Go to next step.
  8. Using scan tool, select DISPLAY DTCS for module that had a loss of communication DTC. If scan tool does not display any DTCs that do not begin with a "U", go to next step. If scan tool displays any DTCs that do not begin with a "U", perform appropriate diagnostic system check for affected system. See «DIAGNOSTIC SYSTEM CHECK»(ref-99721-S29406924942001080900000) table under SELF-DIAGNOSTIC SYSTEM.
  9. Using scan tool, clear DTCs. Continue diagnosing or clearing DTCs until all modules with stored DTCs are repaired.

When multiple Loss Of Communication DTCs are set concurrently, a likely cause is a bad connection at left instrument panel junction block harness connector C1.

DTC with current status cannot be retrieved. To diagnose a current U1300, go to TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS. An intermittent condition is most likely caused by a short to ground condition along the class 2 serial data line.

DTC with current status cannot be retrieved. To diagnose a current U1301, go to TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS. An intermittent condition is most likely caused by a short to voltage condition along the class 2 serial data line.

  1. Perform «INSTRUMENT CLUSTER DIAGNOSTIC SYSTEM CHECK»(ref-99721-S23423005702001082000000) under SELF-DIAGNOSTIC SYSTEM. Go to next step.
  2. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. Turn ignition switch to ON position. If scan tool displays DTC U2001, go to next step. If scan tool does not display DTC U2001, go to step 5.
  3. If scan tool displays DTC U2004, go to step 10. If scan tool does not display DTC U2004, go to next step.
  4. If scan tool displays DTC U2006 or U2007, go to step 6. If scan tool does not display DTC U2006 or U2007, go to step 7.
  5. Turn ignition switch to OFF position. Disconnect BCM Pink 24-pin harness connector C3. BCM is located under right side of instrument panel. (Scheme 6) Turn ignition switch to ON position. Measure voltage between ground and BCM harness connector C3 terminal A3 (Yellow wire). (Scheme 5) If more than 9 volts exist, go to step 9. If 9 volts or less exist, go to step 12.
  6. Turn ignition switch to OFF position. Disconnect BCM Pink 24-pin harness connector C3. BCM is located under right side of instrument panel. (Scheme 6) Turn ignition switch to ON position. Measure voltage between ground and BCM harness connector C3 terminal A7 (Pink/Black wire). (Scheme 5) If more than 9 volts exist, go to step 8. If 9 volts or less exist, go to step 13.
  7. Turn ignition switch to OFF position. Disconnect Instrument Panel Cluster (IPC) Gray 24-pin harness connector. Turn ignition switch to ON position. Measure voltage between ground and IPC harness connector terminal A2 (Pink/Black wire). (Scheme 9) If more than 9 volts exist, go to step 14. If 9 volts or less exist, go to step 15.
  8. Check for short to voltage in Pink/Black wire between BCM harness connector C3 terminal A7 and IPC harness connector terminal A10. If Pink/Black wire is okay, go to step 17. If Pink/Black wire is not okay, repair as necessary. After repair, go to step 20.
  9. Check for short to voltage in Yellow wire between BCM harness connector C3 terminal A3 and IPC harness connector terminal A9. If Yellow wire is okay, go to step 17. If Yellow wire is not okay, repair as necessary. After repair, go to step 20.
  10. Check for open or high resistance in Purple wire between BCM harness connector C1 terminal A8 and IPC/BFC ACC fuse (10-amp) in left instrument panel junction block. Left instrument panel junction block is located on left end of instrument panel. See POWER DISTRIBUTION article in WIRING DIAGRAMS. If Purple wire is okay, go to next step. If Purple wire is not okay, repair as necessary. After repair, go to step 20.
  11. Check for open or high resistance in Orange wire between IPC harness connector terminal A1 and IPC/HVAC BATT fuse (10-amp) in left instrument panel junction block. Left instrument panel junction block is located on left end of instrument panel. See POWER DISTRIBUTION article in WIRING DIAGRAMS. If Orange wire is okay, go to step 16. If Orange wire is not okay, repair as necessary. After repair, go to step 20.
  12. Check for open, high resistance or short to ground in Yellow wire between BCM harness connector C3 terminal A3 and IPC harness connector terminal A9. If Yellow wire is okay, go to step 16. If Yellow wire is not okay, repair as necessary. After repair, go to step 20.
  13. Check for open, high resistance or short to ground in Pink/Black wire between BCM harness connector C3 terminal A7 and IPC harness connector terminal A10. If Pink/Black wire is okay, go to step 16. If Pink/Black wire is not okay, repair as necessary. After repair, go to step 20.
  14. Check for open or high resistance in Black/White wire between IPC harness connector terminals A4 and B10 and ground splice pack, located above left instrument panel junction block. See GROUND DISTRIBUTION article in WIRING DIAGRAMS. Check for short to voltage in Light Blue/Black wire between BCM harness connector C2 terminal B7 and IPC harness connector terminal A2. If Black/White wire and Light Blue/Black wire are okay, go to step 16. If Black/White wire and/or Light Blue/Black wire are not okay, repair as necessary. After repair, go to step 20.
  15. Check for open, high resistance or short to ground in Light Blue/Black wire between BCM harness connector C2 terminal B7 and IPC harness connector terminal A2. If Light Blue/Black wire is okay, go to step 17. If Light Blue/Black wire is not okay, repair as necessary. After repair, go to step 20.
  16. Check IPC harness connector for poor connections or damaged terminals. If no problem is found, go to step 18. If a poor connection exists, repair as necessary. After repair, go to step 20.
  17. Check BCM harness connectors for poor connections or damaged terminals. If no problem is found, go to step 19. If a poor connection exists, repair as necessary. After repair, go to step 20.
  18. Replace IPC. See ANALOG INSTRUMENT PANELS - MALIBU article. After repair, go to step 20.
  19. Replace and program BCM. See «BODY CONTROL MODULE»(ref-99721-S38536342252001073100000) under REMOVAL & INSTALLATION. After repair, go to next step.
  20. Reconnect all disconnected components and connectors. Clear DTCs. Operate vehicle under conditions that set DTC. If DTC resets, go to step 2. If DTC does not reset, system is okay at this time.

Scheme 9

Scheme 9
Scheme 9

TEST A: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE

  1. Connect scan tool to Data Link Connector (DLC). (Scheme 4) DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, go to «TEST B: SCAN TOOL DOES NOT POWER UP»(ref-99721-S10514927462001073100000).
  2. Turn ignition switch to ON position. Attempt to communicate with all control modules on class 2 serial data circuit. See DATA LINK CONNECTORS article in WIRING DIAGRAMS. If any modules communicate with scan tool, go to next step. If no modules communicate with scan tool, go to step 5.
  3. Using scan tool, select DISPLAY DTCS for each module. Record each DTC status (history or current) and which module set the DTC. If any communication DTCs (DTCs with "U" prefix) exist, go to next step. If no communication DTCs exist, check for intermittent or poor connections.
  4. For diagnosis and repair of "U" prefix DTC, perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000).
  5. Turn ignition switch to OFF position. Disconnect scan tool from DLC. Check DLC terminals No. 2 (Purple wire) and No. 5 (Black/White wire) for proper contact. If no problem is found, go to next step. If any looseness or damage exists, repair as necessary. After repair, go to step 16.
  6. Check for open in Black/White wire between DLC terminal No. 5 and ground. Ground point is located on front of engine, near starter. See GROUND DISTRIBUTION article in WIRING DIAGRAMS. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, go to step 16.
  7. Disconnect left instrument panel junction block Brown 68-pin harness connector C1. Disconnect radio Black 24-pin harness connector. Check for open, high resistance, short to ground or short to voltage in Purple wire between DLC terminal No. 2 and left instrument panel junction block harness connector C1 terminal D2. (Scheme 8) If Purple wire is okay, go to next step. If Purple wire is not okay, repair as necessary. After repair, go to step 16.
  8. Check left instrument panel junction block harness connector C1 for poor connections or damaged terminals. (Scheme 8) If no problem is found, go to next step. If poor connection is found, repair as necessary. After repair, go to step 16.
  9. Turn ignition switch to OFF position. Reconnect left instrument panel junction block harness connector C1. Reconnect radio harness connector. Disconnect Electronic Brake Control Module (EBCM) Black 37-pin harness connector. EBCM is located inside left fender on brake pressure modulator valve. Connect scan tool to DLC. Turn ignition switch to ON position. Attempt to communicate with all control modules on class 2 serial data circuit. If no modules communicate with scan tool, go to next step. If any modules communicate with scan tool, go to step 15.
  10. Turn ignition switch to OFF position. Disconnect PCM Blue 80-pin harness connector. PCM is located under left side of instrument panel, near steering column. Turn ignition switch to ON position. Attempt to communicate with all control modules on class 2 serial data circuit. If no modules communicate with scan tool, go to next step. If any modules communicate with scan tool, go to step 15.
  11. Turn ignition switch to OFF position. Disconnect BCM Pink 24-pin harness connector C3. (Scheme 5) BCM is located under right side of instrument panel. (Scheme 6) Turn ignition switch to ON position. Attempt to communicate with all control modules on class 2 serial data circuit. If no modules communicate with scan tool, go to next step. If any modules communicate with scan tool, go to step 15.
  12. Turn ignition switch to OFF position. Disconnect radio Black 24-pin harness connector. Turn ignition switch to ON position. Attempt to communicate with all control modules on class 2 serial data circuit. If no modules communicate with scan tool, go to next step. If any modules communicate with scan tool, go to step 15.
  13. Turn ignition switch to OFF position. Reconnect EBCM harness connector. Disconnect Sensing and Diagnostic Module (SDM) 18-pin natural harness connector. SDM is located under front passenger's seat. Turn ignition switch to ON position. Attempt to communicate with all control modules on class 2 serial data circuit. If no modules communicate with scan tool, go to next step. If any modules communicate with scan tool, go to step 15.
  14. Disconnect EBCM harness connector. Disconnect left instrument panel junction block harness connector C1. Check for high resistance, short to ground or short to voltage in class 2 serial data circuit (Purple wire). See DATA LINK CONNECTORS article in WIRING DIAGRAMS. If Purple wire is okay, go to next step. If Purple wire is not okay, repair as necessary. After repair, go to step 16.
  15. Turn ignition switch to OFF position. Disconnect scan tool. Replace module that was last disconnected. See appropriate article for replacement and programming information. Go to next step.
  16. Reconnect all components and harness connectors. Connect scan tool to DLC. Turn ignition switch to ON position. If scan tool does not communicate, disconnect scan tool, then reconnect to reset communication. Attempt to communicate with all control modules on class 2 serial data circuit. If scan tool communicates with all modules, go to next step. If scan tool does not communicate with all modules, go to step 5.
  17. Using scan tool, select DISPLAY DTCS for each module on class 2 serial data circuit. Record each DTC status (history or current) and which module set the DTC. If any current communication DTCs (DTCs with "U" prefix) exist, go to step 20. If no current communication DTCs exist, go to next step.
  18. If any non-communication DTCs (DTCs without "U" prefix) were recorded, go to next step. If no non-communication DTCs (DTCs without "U" prefix) were recorded, go to step 21.
  19. Perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-99721-S17528030522001080300000). Go to next step.
  20. If all DTCs have been diagnosed, go to next step. If not all DTCs have been diagnosed, go to step 19.
  21. Reconnect all disconnected components and connectors. Using scan tool, clear DTCs.

TEST B: SCAN TOOL DOES NOT POWER UP

  1. Check for open or short to ground in Orange wire between Data Link Connector (DLC) terminal No. 16 and IPC/HVAC BATT fuse (10-amp) in left instrument panel junction block. Left instrument panel junction block is located on left end of instrument panel. If Orange wire is okay, go to next step. If Orange wire is not okay, repair as necessary. After repair, perform appropriate diagnostic system check. See «DIAGNOSTIC SYSTEM CHECK»(ref-99721-S29406924942001080900000) table under SELF-DIAGNOSTIC SYSTEM.
  2. Check for open or high resistance in Black wire between DLC terminal No. 4 and ground splice pack, located above left instrument panel junction block. See GROUND DISTRIBUTION article in WIRING DIAGRAMS. If Black wire is okay, go to next step. If Black wire is not okay, repair as necessary. After repair, perform appropriate diagnostic system check. See «DIAGNOSTIC SYSTEM CHECK»(ref-99721-S29406924942001080900000) table under SELF-DIAGNOSTIC SYSTEM.
  3. Check DLC terminals No. 4 and 16 for poor connections or damaged terminals. If no problem is found, go to next step. If a poor connection exists, repair as necessary. After repair, perform appropriate diagnostic system check. See «DIAGNOSTIC SYSTEM CHECK»(ref-99721-S29406924942001080900000) table under SELF-DIAGNOSTIC SYSTEM.
  4. Check scan tool. Follow scan tool manufacturer's instructions. After obtaining a properly operating scan tool, perform appropriate diagnostic system check. See «DIAGNOSTIC SYSTEM CHECK»(ref-99721-S29406924942001080900000) table under SELF-DIAGNOSTIC SYSTEM.

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