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Service bulletins for the 2020 Cadillac CT4

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.

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

By type

By component

By trouble code

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

Bulletins, newest first
21-NA-2442022-11-02. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT; ELECTRICAL SYSTEM. This service bulletin provides a repair procedure to correct a customer concern of a No Fob detected message on Driver Information Center (DIC) and/or No Crank / No Start condition.
PIT5832C2022-10-17. Service bulletin. UNKNOWN OR OTHER; ELECTRICAL SYSTEM:SOFTWARE; COMMUNICATIONS:BACK UP ALARM. This Preliminary information communicates a diagnostic tip on how to resolve a issue if the serial data authentication configuration did not complete correctly.
PI0592G2022-10-13. Service bulletin. ELECTRICAL SYSTEM. This preliminary information (PI) provides information om Service Programming System (SPS) Error Codes (E4398, E4399, E4403, M4404, M4413, M6954, M6955, E4414, E4423, E4491 or E6961).
13-08-116-001H2022-10-11. Service bulletin. ELECTRICAL SYSTEM. The intent of this service bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them.
21-NA-0682022-10-07. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This warranty administration bulletin provides policy information requirements applicable to key fob replacement under the New Vehicle Limited Warranty or under a Replacement Parts Warranty on 2017-2022 and newer model year vehicles with RPO ATH and AVJ.
PIT5569B2022-08-15. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT; SERVICE BRAKES, AIR:ANTILOCK:WHEEL SPEED SENSOR. This Preliminary information communicates direction and examples when diagnosing multiple DTCs, one of which includes U**** Byte 71 DTC.
22NA0442022-07-18. Service bulletin. STRUCTURE; ELECTRICAL SYSTEM:BODY CONTROL MODULE/BCM; ELECTRICAL SYSTEM. Check Engine MIL Illuminated in DIC Set by Body Control Module with DTC P0607
22-NA-0942022-07-12. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. This service bulletin provides repair information to correct a customer concern of a loss of cabin heat.
22-NA-1152022-07-12. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. This service bulletin provides information for U.S. dealers ONLY to refer to the Battery Maintenance Report to identify vehicles in dealer inventory that require attention.
21NA1312022-06-21. Service bulletin. SEATS:FRONT ASSEMBLY:POWER ADJUST; ELECTRICAL SYSTEM. This service bulletin provides repair information to correct a customer concern of Memory Seat Module Does Not Adjust.
22-NA-1152022-06-06. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM. This service bulletin provides information for U.S. dealers ONLY to refer to the Battery Maintenance Report to identify vehicles in dealer inventory that require attention.
22-NA-1132022-06-06. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; ELECTRICAL SYSTEM. This service bulletin provides repair information to correct a customer concern of Head Up Display (HUD) Blank, Non-Responsive to Brightness, Aim, or Page Controls, DTC U0158 Set.
PIE0661C2022-06-04. Service bulletin. FORWARD COLLISION AVOIDANCE; ELECTRICAL SYSTEM. This engineering information (EI) closure ends the need for further information from the field in regards to a Forward Collision Icon Message Illuminated on Driver Information Center (DIC) and/or No DTCs Set.
22-NA-1072022-06-04. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION. This service bulletin provides repair information to correct a customer concern of a Service AWD Message in DIC at Ignition On with DTC C056D Set.
22NA0122022-05-31. Service bulletin. ELECTRICAL SYSTEM:ADAS:PARKING ASSIST:SENSORS. This service bulletin provides information for dealers/technicians on Stone Chip/Membrane Damage, Broken Connector and/or Sensor Retaining Tabs, and/or Paint Damage of Park Assist Sensors.
PIP4670J2022-04-18. Service bulletin. ELECTRICAL SYSTEM. This Preliminary Information communication provides information to the technician about a no start or another concern after swapping an Engine Control Module or other modules from one vehicle to another. The Global Architecture electrical system associated with these vehicles does not allow controller swaps between vehicles.
PIP5701B2022-04-18. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates that the E01 ECM p/n 12703874 is on part restriction.
PIC6389B2022-04-18. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a parts restriction is in place for the Long Range Radar Module on 2020 Cadillac CT4 and CT5.
PIP58432022-04-18. Service bulletin. ELECTRICAL SYSTEM; EXTERIOR LIGHTING. This Preliminary information communicates to the dealers information related to a Malfunction Indicator Lamp (MIL) Illuminated During Cold Ambient Temperatures with DTCs P30C3 and/or P30BF P30C7 P30CB Setting.
PIE0661B2022-04-02. Service bulletin. ELECTRICAL SYSTEM; FORWARD COLLISION AVOIDANCE. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to a Forward Collision Icon Message Illuminated on Driver Information Center (DIC) and/or No DTCs Set.
PIC64502022-03-14. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a process to correct the concern of Unable to contact OnStar after the 3G EOL on 2015-2022 model year vehicles in the United States.
PIC6384H2022-02-14. Service bulletin. STRUCTURE; ELECTRICAL SYSTEM. This Preliminary information communicates a parts restriction is in place for the Body Control Module on 2020 Cadillac CT4, CT5, Chevrolet Corvette, Suburban, Tahoe and GMC Yukon.
PIC6048N2022-02-14. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN; STEERING; AIR BAGS; LANE DEPARTURE; BACK OVER PREVENTION. This Preliminary Information communicates to the technician that some customers may comment on the operation of their haptic seat during a Lane Keep Assist event. Lane Keep Assist works differently than Lane Departure Warning. The Lane Keep Assist icon is solid amber, Forward Camera Module is actively commanding a torque to Electronic Power Steering. This means that the driver should also feel some feedback from the steering wheel. No Chimes or haptic in the seat. Lane Keep Assist icon is flashing amber; Forward Camera Module is actively commanding torque to Electronic Power Steering. This will also be accompanied with Lane Departure Warning chimes and haptic in the seat feedback based on the setting chosen in the vehicle settings. This will take place when the vehicle has crossed lane marking by (40 cm) or (15.75 in).
21NA2562022-02-14. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); EXTERIOR LIGHTING. This service bulletin provides repair information for dealers/technicians to correct a customer concern of a Malfunction Indicator Lamp Illuminated with DTC P26BB Set.
PIP5675G2022-01-24. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT. This Preliminary information communicates to the dealer that a customer may comment that the MIL light is illuminated. The technician may find P1098 and/or P26BB set current or history. That this may be caused by a software anomaly, and that GM is currently looking into the issue. It provides testing and related direction based on the results.

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