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Service bulletins for the 2015 Chevrolet Silverado

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

3099 on file from NHTSA, as of 2026-10-19.

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Only bulletins with component: Electrical system are shown. Show all

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PIC3278F2017-03-14. Service bulletin. EQUIPMENT:ELECTRICAL; ELECTRICAL SYSTEM. THIS PRELIMINARY INFORMATION COMMUNICATION PROVIDES INFORMATION TO THE TECHNICIAN THE STEPS NEEDED TO DIAGNOSE AND REPAIR THE VEHICLES THAT MAY HAVE UNWANTED OR PHANTOM PHONE CALLS. TECHNICIAN WILL NEED TO DETERMINE WHAT TYPE OF CALL THE CUSTOMER IS HAVING THAT IS UNWANTED. THE VEHICLE MAY RECEIVE AN INCOMING CALL JUST LIKE ANY OTHER PHONE. TYPICALLY THE CUSTOMER WILL HEAR THE PHONE RINGING IN THE VEHICLE. THIS SCENARIO ALSO INCLUDES INCOMING BLUETOOTH CALLS. ONE TYPE OF UNWANTED CALL CAN BE MADE IF THE KEY PAD IS FAULTY THE ONSTAR SYSTEM WILL TRY TO MAKE A BLUE BUTTON CALL FOR SHORTED VOLTAGE IN THE CIRCUITS. THE ONSTAR MODULE COULD HAVE AN INTERNAL FAULT AND PRODUCE A PHONE UNAVAILABLE AUDIO MESSAGE ALSO IT MAY HAVE A DIAGNOSTIC TROUBLE CODE U1500 OR B1000. REFER TO DIAGNOSTICS FOR THE DIAGNOSTIC TROUBLE CODE MAKING SURE TO FOLLOW ANY APPLICABLE BULLETINS OR PRELIMINARY INFORMATION SHEETS. A GREADYH OR GONSTAR READYH AUDIO MESSAGE HEARD WHILE DRIVING. IN SOME CASES IT HAS BEEN FOUND THAT THE CUSTOMER IS INADVERTENTLY PRESSING THE PUSH TO TALK BUTTON ON THE STEERING WHEEL CONTROLS. ON RARE OCCASIONS, OTHER ISSUES IN THE STEERING COLUMN OR STEERING WHEEL CONTROL SYSTEM MAY INDUCE THIS CONCERN.
PI1354D2017-03-13. Service bulletin. STEERING:HYDRAULIC POWER ASSIST:POWER STEERING FLUID; ELECTRICAL SYSTEM; SUSPENSION. THIS PRELIMINARY INFORMATIONAL BULLETIN PROVIDES INFORMATION ON A PROCEDURE FOR DIAGNOSING AND REPAIRING VIBRATIONS CAUSED BY THE WHEEL AND TIRE, AXLE COMPONENTS AND/OR PROPELLER SHAFTS.
G-1947842017-02-24. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL. 14126 - SERVICE UPDATE. THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO REPROGRAM THE INSTRUMENT PANEL CLUSTER ON CERTAIN VEHICLES. ALSO INVOLVED ARE CERTAIN 2015 MY CHEVROLET SUBURBAN, TAHOE AND GMC YUKON VEHICLES. THESE VEHICLES MAY HAVE AN ODOMETER READING AT “PEEK IN” (I.E. DRIVER INFORMATION CENTER (DIC) SCREEN WHEN THE VEHICLE IS IN THE OFF POWER MODE BUT THE CLUSTER IS AWAKENED BY OPENING THE CAR DOOR OR USING THE KEY FOB) DOES NOT MATCH THE SEASON ODOMETER READING WHEN THE VEHICLE IS IN THE RUN POWER MODE. THE TRIP A/B AND FUEL ECONOMY DISPLAYS MAY ALSO BE INCORRECT. THIS CONDITION OCCURS, WHEN THE VEHICLE SITS FOR AN EXTENDED PERIOD OF TIME AND, NORMAL PARASITIC CURRENT DRAWS DEPLETE THE BATTERY STATE OF CHARGE TO LESS THAN 12 VOLTS AND, THE VEHICLE IS IN THE OFF POWER MODE WHEN THE CLUSTER IS AWAKENED AS DESCRIBED ABOVE.
G-1958782017-02-23. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL. 14126A - SERVICE UPDATE (REVISED PROGRAMMING INFORMATION). THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO REPROGRAM THE INSTRUMENT PANEL CLUSTER ON CERTAIN VEHICLES. THESE VEHICLES MAY HAVE AN ODOMETER READING AT “PEEK IN” (I.E. DRIVER INFORMATION CENTER (DIC) SCREEN WHEN THE VEHICLE IS IN THE OFF POWER MODE BUT THE CLUSTER IS AWAKENED BY OPENING THE CAR DOOR OR USING THE KEY FOB) DOES NOT MATCH THE SEASON ODOMETER READING WHEN THE VEHICLE IS IN THE RUN POWER MODE. THE TRIP A/B AND FUEL ECONOMY DISPLAYS MAY ALSO BE INCORRECT. THIS CONDITION OCCURS, WHEN THE VEHICLE SITS FOR AN EXTENDED PERIOD OF TIME AND, NORMAL PARASITIC CURRENT DRAWS DEPLETE THE BATTERY STATE OF CHARGE TO LESS THAN 12 VOLTS AND, THE VEHICLE IS IN THE OFF POWER MODE WHEN THE CLUSTER IS AWAKENED AS DESCRIBED ABOVE.
14126B2017-02-06. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; ELECTRICAL SYSTEM:12V/24V/48V BATTERY. 14126B - SERVICE UPDATE (REVISED PROGRAMMING INFORMATION). THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO REPROGRAM THE INSTRUMENT PANEL CLUSTER ON CERTAIN VEHICLES. THESE VEHICLES MAY HAVE AN ODOMETER READING AT “PEEK IN” (I.E. DRIVER INFORMATION CENTER (DIC) SCREEN WHEN THE VEHICLE IS IN THE OFF POWER MODE BUT THE CLUSTER IS AWAKENED BY OPENING THE CAR DOOR OR USING THE KEY FOB) DOES NOT MATCH THE SEASON ODOMETER READING WHEN THE VEHICLE IS IN THE RUN POWER MODE. THE TRIP A/B AND FUEL ECONOMY DISPLAYS MAY ALSO BE INCORRECT. THIS CONDITION OCCURS, WHEN THE VEHICLE SITS FOR AN EXTENDED PERIOD OF TIME AND, NORMAL PARASITIC CURRENT DRAWS DEPLETE THE BATTERY STATE OF CHARGE TO LESS THAN 12 VOLTS AND, THE VEHICLE IS IN THE OFF POWER MODE WHEN THE CLUSTER IS AWAKENED AS DESCRIBED ABOVE.
142842017-02-02. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY:CABLES. 14284 - CUSTOMER SATISFACTION PROGRAM. CERTAIN VEHICLES EQUIPPED WITH THE AUXILIARY SWITCH BANK (RPO 9L7) MAY HAVE AN ELECTRICAL ISSUE CREATED WHEN ONE OR BOTH UPFITTER FUSES USED FOR THE INSTRUMENT PANEL MOUNTED AUXILIARY SWITCH BANK ARE MOVED FROM THE BATTERY FEED TO THE IGNITION FEED POSITION. IF THE FUSE POSITIONS ARE ALTERED, THE ENGINE COULD CONTINUE TO RUN AFTER THE IGNITION SWITCH IS TURNED OFF. THERE COULD ALSO BE AN INADVERTENT GLOWING OF THE AUXILIARY SWITCH INDICATORS, ADDITIONAL PARASITIC CURRENT DRAIN, OR A NO START CONDITION. DEALERS ARE TO REPLACE THE UNDERHOOD ELECTRICAL CENTER.
141542017-02-02. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY:CABLES. 14154 - SERVICE UPDATE. THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO RELOCATE THE SEPARATE 250 AMP FUSE INTO THE PRE-FUSE ASSEMBLY ON TOP OF THE VEHICLE BATTERY ON CERTAIN VEHICLES EQUIPPED WITH A 220 AMP GENERATOR (RPO KW5). THESE VEHICLES MAY, DUE TO CORROSION AT THE ENDS OF THE FUSE, EXPERIENCE A RESISTANCE BUILD-UP THAT DOES NOT ALLOW CURRENT TO FLOW THROUGH THE FUSE, RESULTING IN THE GENERATOR NOT BEING ABLE TO CHARGE THE VEHICLE BATTERY. THE BATTERY SYMBOL MAY APPEAR ON THE IP AND A MESSAGE IN THE DRIVER INFORMATION CENTER WILL SHOW “SERVICE BATTERY CHARGING SYSTEM.” AS THE BATTERY LOSES CHARGE, THE VEHICLE MAY STALL OR NOT BE ABLE TO START WHEN THE BATTERY GOES BELOW 11.3 VOLTS. DEPENDING ON THE STATE OF CHARGE OF THE BATTERY WHEN THIS OCCURS, THE VEHICLE MAY HAVE BETWEEN 50-85 MINUTES BEFORE ANY POTENTIAL STALL CONDITION.
14154 MESSAGE VI2017-02-02. Service bulletin. ELECTRICAL SYSTEM:WIRING:FUSES AND CIRCUIT BREAKERS. 14154 - SERVICE UPDATE (VIN LIST ADDED). GLOBAL CONNECT MESSAGE G_0000205220 DATED NOVEMBER 21, 2014, ANNOUNCED THE RELEASE OF SERVICE UPDATE BULLETIN 14154. THE MESSAGE DID NOT INCLUDE A BAC SORTED VIN LIST IDENTIFYING INVOLVED IN-STOCK UNITS. THIS HAS BEEN CORRECTED, PLEASE SEE THE ATTACHED VIN LIST ALONG WITH A COURTESY COPY OF THE BULLETIN. WE APOLOGIZE FOR ANY INCONVENIENCE THIS MAY HAVE CAUSED.
14725A2017-02-01. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM:WIRING. 14725A - SERVICE UPDATE (REVISED SERVICE INFORMATION). THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO TIE STRAP THE “MAIN” AND “BCM” BRANCHES OF THE BODY HARNESS (NEAR THE FRONT OF DASH PASS-THROUGH INSIDE THE VEHICLE) TOGETHER TO PREVENT THEM FROM COMING IN CONTACT WITH PARK BRAKE BRACKET ON CERTAIN VEHICLES. THESE VEHICLES MAY HAVE EXPOSED BODY HARNESS WIRES IN CLOSE PROXIMITY TO THE PARKING BRAKE BRACKET AT THE FRONT DASH PASS-THROUGH INSIDE THE VEHICLE. THE EXPOSED BODY HARNESS WIRES CAN RUB AGAINST OR BE PINCHED BY THE BRAKE BRACKET. WHILE THERE IS NO EVIDENCE OF THIS HAPPENING IN CUSTOMER VEHICLES, IF THE WIRES WERE TO BE SUFFICIENTLY DAMAGED FROM RUBBING AGAINST OR BEING PINCHED BY THE BRAKE BRACKET, CERTAIN ELECTRICAL SYSTEMS COULD BE AFFECTED. FOR EXAMPLE, SUFFICIENT DAMAGE TO THE WIRES COULD RESULT IN THE LOSS OF VARIOUS EXTERIOR LIGHTS, WIPERS, THE DRIVER’S AIRBAG TELLTALE LIGHT, THROTTLE CONTROL, DEFOG CONTROLS, OR TRAILER BRAKE CONTROLS. IN ADDITION, WHILE THERE IS NO EVIDENCE OF ANY STALLS RESULTING FROM THIS CONDITION, IT IS POSSIBLE THAT IF THE RUN/CRANK WIRE WAS SUFFICIENTLY DAMAGED, IT COULD RESULT IN AN ENGINE STALL. DEPENDING ON WHICH CIRCUIT IS DAMAGED, A TELLTALE OR DIC MESSAGE MAY BE DISPLAYED ALERTING THE CUSTOMER THAT AN ISSUE EXISTS.
152172017-02-01. Service bulletin. ENGINE; ELECTRICAL SYSTEM:WIRING. 15217 - SERVICE UPDATE. THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO INSPECT THE ROUTING OF THE TRANSMISSION CONTROL MODULE (TCM) BRANCH OF THE ENGINE-WIRING HARNESS ON CERTAIN 2015 CHEVROLET SILVERADO AND GMC SIERRA HD VEHICLES THAT ARE EQUIPPED WITH DUAL GENERATORS (KHB). DEALERS ARE TO ENSURE THAT THE HARNESS IS ROUTED PROPERLY AND SECURED WITH A FIR-TREE CLIP. ON THESE VEHICLES, THE TCM BRANCH OF THE ENGINE-WIRING HARNESS MAY HAVE BEEN MISROUTED AND NOT SECURED WITH AN EXISTING FIR-TREE CLIP ON THE AUXILIARY-POSITIVE BATTERY CABLE, POTENTIALLY ALLOWING THE HARNESS TO COME IN CONTACT WITH EITHER THE AUXILIARY-GENERATOR PULLEY OR BELT.
14395A2017-02-01. Service bulletin. ELECTRICAL SYSTEM. 14395A - CUSTOMER SATISFACTION PROGRAM (REVISED LABOR TIME). ON SOME 2015 MODEL YEAR BUICK ENCORE, LACROSSE, REGAL, AND VERANO; CADILLAC ATS, CTS, ELR, ESCALADE, SRX AND XTS; CHEVROLET COLORADO, CORVETTE, CRUZE, EQUINOX, IMPALA, MALIBU, SILVERADO, SONIC, SPARK, SS, SUBURBAN, TAHOE, TRAX, AND VOLT; AND GMC CANYON, SIERRA, TERRAIN, AND YUKON VEHICLES, A PERFORMANCE ISSUE WITH THE ONSTAR® MODULE MIGHT IMPACT THE VEHICLE'S BATTERY LIFE. THIS CAN CAUSE A DEAD BATTERY IF THE VEHICLE IS NOT STARTED FOR APPROXIMATELY 4 DAYS. THIS CONDITION CAN OCCUR EVEN IF THE ONSTAR® SYSTEM IS NOT ACTIVE. DEALERS ARE TO REPLACE THE ONSTAR® MODULE. IF THE CUSTOMER DOES NOT HAVE AN ACTIVE ONSTAR® SUBSCRIPTION, THE ONSTAR® MODULE IS TO BE DEACTIVATED AFTER REPLACEMENT.
142812017-02-01. Service bulletin. SEATS; ELECTRICAL SYSTEM. 14281 - CUSTOMER SATISFACTION PROGRAM. CERTAIN 2014-2015 MODEL YEAR CHEVROLET SILVERADO, SUBURBAN, AND TAHOE MODEL VEHICLES AND 2014-2015 MODEL YEAR GMC SIERRA AND YUKON MODEL VEHICLES EQUIPPED WITH A DEALER INSTALLED REAR ENTERTAINMENT SYSTEM MAY HAVE A CONDITION IN WHICH THE REAR SEAT ENTERTAINMENT SYSTEM IN VEHICLES WAS RELEASED AS A DEALER ACCESSORY BEFORE FINAL GENERAL MOTORS VALIDATION APPROVAL. VALIDATION APPROVAL AT GM REQUIRES VERY RIGOROUS TESTING PRIOR TO RELEASE, WHICH, IN MANY CASES, GOES BEYOND WHAT IS REQUIRED TO COMPLY WITH GOVERNMENTAL SAFETY STANDARDS. THESE VEHICLES, AS EQUIPPED, STILL MEETS ALL FEDERAL MOTOR VEHICLE SAFETY STANDARDS. DEALERS ARE TO REMOVE AND REPLACE THE HINGED SCREEN STYLE REAR SEAT ENTERTAINMENT SYSTEM, WITH A REVISED SYSTEM FEATURING AN INTEGRAL SCREEN.
154112017-01-31. Service bulletin. ELECTRICAL SYSTEM:WIRING; ELECTRICAL SYSTEM. 15411 - SERVICE UPDATE. THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO INSTALL FUSES AND RELAYS AS REQUIRED IN THE UNDERHOOD ELECTRICAL CENTER (UEC) ON CERTAIN 2015 MODEL YEAR CHEVROLET SILVERADO AND GMC SIERRA VEHICLES EQUIPPED WITH AN ACCESSORY-WIRING-JUNCTION-BLOCK (RPO 9L7). THESE VEHICLES MAY HAVE MISSING FUSES AND RELAYS. THE CUSTOMER MAY NOTICE THAT THE AUXILIARY SWITCHES ARE INOPERATIVE AFTER THE FUNCTION IS ADDED TO THE VEHICLE.
15038 MESSAGE2017-01-31. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. 15038 - DEALER MESSAGE ONLY. SELECT 2015 VEHICLES WILL RECEIVE A SOFTWARE DOWNLOAD VIA ONSTAR® TO UPDATE THE SOFTWARE FOR THE ELECTRONIC CLIMATE CONTROL (ECC) SYSTEM. THE UPDATE WILL BE PERFORMED ON DEALER INVENTORY VEHICLES, WITH THE UPDATE OCCURRING DURING THE NIGHT TIME HOURS OF 1AM TO 5AM EDT. UPDATES WILL BE ROLLED OUT TO THE INVENTORY STARTING 6/29/2015 AND COMPLETE BY END OF SEPTEMBER 2015. NO FURTHER ACTION IS REQUIRED BY THE DEALER. THIS UPDATE WILL TAKE APPROXIMATELY 15 MINUTES.
151152017-01-30. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. 15115 - SERVICE UPDATE. THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO REPROGRAM AND UPDATE THE GLOW-PLUG CONTROL MODULE WITH NEW SOFTWARE ON CERTAIN 2015 MODEL YEAR CHEVROLET SILVERADO HD CREW, HD CREW LTZ, HD REGULAR, HD EXT, HD EXT LTZ VEHICLES EQUIPPED WITH A DURAMAX DIESEL ENGINE (RPO LML) AND CERTAIN 2015 MODEL YEAR GMC SIERRA HD CREW, HD CREW DENALI, HD REGULAR, HD EXT VEHICLES EQUIPPED WITH A DURAMAX DIESEL ENGINE (RPO LML). THE SOFTWARE UPDATE LIMITS THE INTAKE-AIR HEATER INPUT VOLTAGE TO 13.5V. WHEN THE SYSTEM VOLTAGE EXCEEDS 13.5V, THE HEATER’S FIELD-EFFECT TRANSISTOR CAN GENERATE EXCESSIVE HEAT. THIS HEAT CAN CAUSE A SHORT CIRCUIT IN THE TRANSISTOR AND, IN RARE CASES, A FIRE IN THE VEHICLE’S ENGINE COMPARTMENT.
157952017-01-26. Service bulletin. VISIBILITY:REARVIEW MIRRORS/DEVICES:EXTERIOR; ELECTRICAL SYSTEM. 15795 - SERVICE UPDATE. VEHICLES INVOLVED IN THIS SERVICE UPDATE WERE PLACED ON STOP DELIVERY OCTOBER 16, 2015. THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO INSTALL A MIRROR SWITCH, BEZEL AND WIRE HARNESS IN CERTAIN VEHICLES EQUIPPED WITH POWER OUTSIDE REAR VIEW MIRRORS (RPO DL8 OR DPN). THESE VEHICLES WERE BUILT WITHOUT A MIRROR ADJUSTMENT SWITCH ON THE DRIVER’S SIDE DOOR PAD CAUSING THE INABILITY TO ADJUST THE GLASS POSITION OF THE POWER OUTSIDE REAR VIEW MIRROR.
PIT5457A2016-11-03. Service bulletin. ELECTRICAL SYSTEM. THIS PRELIMINARY INFORMATION COMMUNICATION ADVISES THE TECHNICIAN ON THE STEPS FOR DIAGNOSING THE CONCERN, AND COMPLETING A WIRING REPAIR. THE VEHICLE MAY HAVE A SERVICE ANTILOCK BRAKING SYSTEM, TRACTION CONTROL, POWER STEERING OR SUSPENSION SYSTEM MESSAGE ON THE DRIVERS INFORMATION CENTER.
PIT5288D2016-11-03. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. THIS PRELIMINARY INFORMATION COMMUNICATION ADVISES THE TECHNICIAN ON THE STEPS TO DIAGNOSE THE CONCERN. CUSTOMER'S POSSIBLE CONCERNS ARE: REMOTE KEYLESS ENTRY INOPERATIVE, PASSIVE ENTRY AND START INOPERATIVE, NO FOB DETECT MESSAGE ON DRIVERS INFORMATION CENTER, SERVICE TIRE PRESSURE SYSTEM, NO AUDIO, TOUCH SCREEN INOPERATIVE, OR RADIO AND/OR DRIVERS INFORMATION CENTER DISPLAY BLANK INOPERATIVE.
PIP5198B2016-11-01. Service bulletin. ELECTRICAL SYSTEM. THIS PRELIMINARY INFORMATION COMMUNICATION ADVISES THE TECHNICIAN ON THE STEPS FOR DIAGNOSING THE CONCERN. THE VEHICLE MAY HAVE WARNING LAMPS AND/OR MIL ILLUMINATED WITH A DIESEL EXHAUST FLUID (DEF) MESSAGE DISPLAYED ON THE CLUSTER. WIRING HARNESS REPAIR INSTRUCTIONS ARE PROVIDED.
PIP5189B2016-11-01. Service bulletin. ELECTRICAL SYSTEM; ENGINE. THIS PRELIMINARY INFORMATION COMMUNICATION ADVISES THE TECHNICIAN ON THE STEPS TO DIAGNOSE AND REPAIR THE CONCERN OF BLACK SMOKE WHEN STARTING THE VEHICLE AFTER SITTING.
PIP5168E2016-11-01. Service bulletin. ELECTRICAL SYSTEM. THIS PRELIMINARY INFORMATION COMMUNICATION ADVISES THE TECHNICIAN ON THE STEPS TO DIAGNOSE THE CONCERN, AND THE STEPS TO REPAIR THE CONCERN OF THE VEHICLE CRANKS BUT DOES NOT START. THE TECHNICIAN IS TO INSPECT FOR A SHEARED CAM PIN IN THE ENGINE.
PIC6198A2016-11-01. Service bulletin. ELECTRICAL SYSTEM. THIS PRELIMINARY INFORMATION COMMUNICATION ADVISES THE TECHNICIAN ON STEPS TO PERFORM TO DETERMINE IF THE CUSTOMER'S BATTERY DRAIN CONCERN IS BEING CAUSED BY A KNOWN CONCERN WITH BLUETOOTH CALL TRANSFER OPERATION WHEN EXITING THE VEHICLE. IF THE CONCERN IS DUPLICATED AT THE DEALER WITH THE ONSTAR LED IS STILL GREEN AFTER THE VEHICLE IS TURNED OFF AND THE BLUETOOTH CALL WAS DISCONNECTED. DEALER SHOULD ADVISES THAT ENGINEERING IS AWARE OF THE CONCERN AND IS CURRENTLY INVESTIGATING THE ISSUE.
PIC4935E2016-10-25. Service bulletin. ELECTRICAL SYSTEM. THIS PRELIMINARY INFORMATION COMMUNICATION PROVIDES INFORMATION TO HELP THE DEALERSHIP TECHNICIANS PERFORM A PARASITIC DRAIN TEST FOR THE ONSTAR MODULE. WHEN PERFORMING BATTERY PARASITIC DRAIN TEST, THERE MAY BE SOME CONFUSION AS TO WHAT THE NORMAL POWER CONSUMPTION READING SHOULD BE FROM THE ONSTAR SYSTEM.
14284A2016-10-24. Service bulletin. ELECTRICAL SYSTEM. 14284A – CUSTOMER SATISFACTION PROGRAM (POPULATION INCREASED, EXPIRATION DATE EXTENDED, PART INFORMATION REVISED). VEHICLES VEHICLES EQUIPPED WITH THE AUXILIARY SWITCH BANK OPTION MAY HAVE AN ELECTRICAL ISSUE CREATED WHEN ONE OR BOTH UPFITTER FUSES USED FOR THE INSTRUMENT PANEL MOUNTED AUXILIARY SWITCH BANK ARE MOVED FROM THE BATTERY FEED TO THE IGNITION FEED POSITION. IF THE FUSE POSITIONS ARE ALTERED, THE ENGINE COULD CONTINUE TO RUN AFTER THE IGNITION SWITCH IS TURNED OFF. THERE COULD ALSO BE AN INADVERTENT GLOWING OF THE AUXILIARY SWITCH INDICATORS, ADDITIONAL PARASITIC CURRENT DRAIN, OR A NO START CONDITION. DEALERS ARE TO REPLACE THE UNDERHOOD ELECTRICAL CENTER.
PIT55222016-10-24. Service bulletin. ELECTRICAL SYSTEM. THIS PRELIMINARY INFORMATION COMMUNICATION PROVIDES INFORMATION TO THE TECHNICIAN ABOUT WHEN PROGRAMING THE IMMOBILIZER THEFT LEARN IT MAY NOT COMPLETE AND/OR SHOW "CONTROLLER ID NOT SUPPORTED" AFTER THE FIRST FEW MINUTES INTO THE LEARN EVENT. TECHNICIAN WILL NEED TO REMOVE POWER FROM THE ONSTAR MODULE BEFORE PERFORMING A IMMOBILIZER THEFT LEARN.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.