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Service bulletins for the 2021 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.

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

By type

By component

By trouble code

By topic

Bulletins, newest first
PIP5865E2025-08-04. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates the possibility of DTC P30BF failing on low mile vehicles due to the possibility of the cylinder 1/2 sliding barrel binding on intake camshaft.
N242435630-052025-07-23. Service campaign. UNKNOWN OR OTHER. Customer Satisfaction Program. Certain model years and vehicle makes noted in the table above may have a condition where the battery is at risk for a drain following an over-the-air update. Dealers are to reprogram the serial data gateway module.
PIP5601C2025-07-23. Service bulletin. UNKNOWN OR OTHER. This PI communicates the requirement to provide a pico file to receive diagnostic assistance from TAC.
N242480631-042025-07-23. Service campaign. UNKNOWN OR OTHER. Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause harsh shifting, setting a service engine soon message, reduced engine performance or P0747 diagnostic trouble code. This special coverage covers vehicles that return after TCM Update Product Safety N242480630 and have P0747 condition described above for a period of 15 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after March 6, 2025, are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to March 6, 2025, must be submitted to the Service Contract provider. Vehicle owners or lessees who paid for repairs referenced in this Special Coverage (“Customers”) are eligible for reimbursement of their reasonable and customary expenses in accordance with the procedures specified below. The conditional right to reimbursement is provided by GM solely in the interest of customer satisfaction and is personal to Customers. Customers may not assign and GM does not consent to any assignment of any Customer’s right to submit reimbursement claims, or to receive reimbursement, or any other rights granted by this Special Coverage to any third party, including but not limited to service contract providers, and this Special Coverage is not intended to and does not confer any third party beneficiary, subrogation or contribution rights, or any other rights to reimbursement, against GM, whether in law, equity or otherwise, on any third parties. Dealers are to install a new control valve body. The repairs will be made at no charge to the customer.
PIP5601B2025-07-23. Service bulletin. UNKNOWN OR OTHER. This PI communicates the requirement to provide a pico file to receive diagnostic assistance from TAC.
15-NA-0102025-07-07. Service bulletin. ENGINE. This service bulletin provides information to dealership personnel for new vehicles with less than 1,000 miles that may not pass California smog inspection or smog inspection in other states.
PIT5832V2025-06-30. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates a diagnostic tip on how to resolve a issue if the serial data authentication configuration did not complete correctly.
PIT64012025-06-30. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates a diagnostic tip on how to resolve a issue of the horn sounding when vehicle doors are being closed and the key in vehicle reminder set to off.
PIC6086J2025-06-30. Service bulletin. UNKNOWN OR OTHER. This PI communicates a procedure to clean oil leaking from the rain sensor.
PIT63982025-06-29. Service bulletin. UNKNOWN OR OTHER. This PI involves DTC U3000 SYM49 Set falsely In The Serial Data Gateway Module and dealerships are to reset the module by cycling the battery.
PIT6180A2025-06-29. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates assistance in locating the Rear seat belt comfort guides in the parts catalog.
25-NA-0372025-06-26. Service bulletin. ENGINE. This bulletin advises the tech that the Exhaust Roller Follower may be the issue with the engine Ticking noise, misfire or rough run and what to replace if found the cause.
PIP4902S2025-06-24. Service bulletin. UNKNOWN OR OTHER. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
N252494770-012025-06-20. Service campaign. UNKNOWN OR OTHER. Amendments to the Song-Beverly Act (SBA) California warranty law provides vehicle owners with an opportunity to submit a written notice to GM before filing a lawsuit seeking a vehicle repurchase. If such a notice is not provided to GM, then the vehicle owner is prevented from seeking civil penalties in litigation. Vehicle owners of the affected vehicles will be mailed an owner’s manual and warranty insert containing this information in English and Spanish.
N242480631-032025-06-18. Warranty extension. UNKNOWN OR OTHER. Special Coverage. Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause harsh shifting, setting a service engine soon message, reduced engine performance or P0747 diagnostic trouble code. This special coverage covers vehicles that return after TCM Update Product Safety N242480630 and have P0747 condition described above for a period of 15 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after March 6, 2025, are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to March 6, 2025, must be submitted to the Service Contract provider. Vehicle owners or lessees who paid for repairs referenced in this Special Coverage (“Customers”) are eligible for reimbursement of their reasonable and customary expenses in accordance with the procedures specified below. The conditional right to reimbursement is provided by GM solely in the interest of customer satisfaction and is personal to Customers. Customers may not assign and GM does not consent to any assignment of any Customer’s right to submit reimbursement claims, or to receive reimbursement, or any other rights granted by this Special Coverage to any third party, including but not limited to service contract providers, and this Special Coverage is not intended to and does not confer any third party beneficiary, subrogation or contribution rights, or any other rights to reimbursement, against GM, whether in law, equity or otherwise, on any third parties. Dealers are to install a new control valve body. The repairs will be made at no charge to the customer.
N2524947702025-06-17. Service campaign. UNKNOWN OR OTHER. Amendments to the Song-Beverly Act (SBA) California warranty law provides vehicle owners with an opportunity to submit a written notice to GM before filing a lawsuit seeking a vehicle repurchase. If such a notice is not provided to GM, then the vehicle owner is prevented from seeking civil penalties in litigation. Vehicle owners of the applicable vehicles will be mailed an owner’s manual and warranty insert containing this information in English and Spanish.
21-NA-2402025-06-16. Service bulletin. ENGINE. This service bulletin provides diagnostic repair information to correct an oil leak in the engine.
PI0281L2025-06-12. Service bulletin. STEERING; POWER TRAIN; SUSPENSION. This preliminary informational (PI) bulletin provides information to dealership personnel that may be helpful when addressing underbody component corrosion with customers.
25-NA-1002025-06-12. Service bulletin. ENGINE. This warranty administration bulletin provides policy information on vehicles outside of a California Emissions State who move to and register their vehicle in a California Emission State may be entitled to the 7 year, 70,000-mile Emission Select State Component Limited Warranty.
PIT5074R2025-06-04. Service bulletin. UNKNOWN OR OTHER. This Preliminary Information communication provides information to the technician about the use of J-35616-64B and Mini 50 terminal test probe, replacement terminals, and terminated leads.
PIT5074R2025-06-04. Service bulletin. UNKNOWN OR OTHER. This Preliminary Information communication provides information to the technician about the use of J-35616-64B and Mini 50 terminal test probe, replacement terminals, and terminated leads.
PIT5074R2025-06-04. Service bulletin. UNKNOWN OR OTHER. This Preliminary Information communication provides information to the technician about the use of J-35616-64B and Mini 50 terminal test probe, replacement terminals, and terminated leads.
24-NA-2292025-06-03. Service bulletin. ELECTRICAL SYSTEM. This bulletin provides a procedure on how to check for a battery drain utilizing the Picoscope and how to measure the load on the system that may be causing a drain.
PIT5966E2025-05-29. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.
N242480631-022025-05-27. Service campaign. POWER TRAIN. Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause harsh shifting, setting a service engine soon message, reduced engine performance or P0747 diagnostic trouble code. This special coverage covers vehicles that return after TCM Update Product Safety N242480630 and have P0747 condition described above for a period of 15 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after March 6, 2025, are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to March 6, 2025, must be submitted to the Service Contract provider. Vehicle owners or lessees who paid for repairs referenced in this Special Coverage (“Customers”) are eligible for reimbursement of their reasonable and customary expenses in accordance with the procedures specified below. The conditional right to reimbursement is provided by GM solely in the interest of customer satisfaction and is personal to Customers. Customers may not assign and GM does not consent to any assignment of any Customer’s right to submit reimbursement claims, or to receive reimbursement, or any other rights granted by this Special Coverage to any third party, including but not limited to service contract providers, and this Special Coverage is not intended to and does not confer any third party beneficiary, subrogation or contribution rights, or any other rights to reimbursement, against GM, whether in law, equity or otherwise, on any third parties. Dealers are to install a new control valve body. The repairs will be made at no charge to the customer.

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