2021 Cadillac CT4 Service and Repair Manual

4.7 · Trusted by 14,000+ mechanics & DIYers
Regular price $49.99 USD
  • Lightning-Fast Downloads
    Optimized files — even slow connections handle it
  • Instant Search & Navigation
    Jump to any procedure or spec with one click
  • Print One or All Pages
    Bring only the pages you need to the shop
  • Covers Every System & Component
    Every procedure for the 2021 Cadillac CT4
Sample Preview

Unlock the Full Manual

Complete repair procedures
Wiring diagrams & schematics
Torque specifications
Full search & bookmarks
$49.99
Buy 2+ Manuals, Save 20% Discount applied automatically at checkout
20% OFF
Secure Checkout
No Subscriptions
Factory-Grade Data

2021 Cadillac CT4 service and repair manual — a detailed, factory-style reference for maintenance, diagnostics, and repair. Use it to confirm correct procedures, specifications, and system coverage before you start work.

Built for technicians and DIY owners, this manual helps you troubleshoot accurately, follow step-by-step repair procedures, and use wiring diagrams and system sections to diagnose problems faster.

What’s included

  • Step-by-step repair procedures and service information
  • Specifications and reference data (where provided)
  • Electrical coverage with wiring diagrams
  • Coverage across key systems: engine, transmission, brakes, steering, suspension, HVAC, and more

Trims covered

  • V Sedan 4-Door
  • Sport Sedan 4-Door
  • Luxury Sedan 4-Door
  • Premium Luxury Sedan 4-Door

Engines covered

  • 2.7L 2720CC 166Cu. In. l4 GAS DOHC Turbocharged
  • 2.0L 1998CC 122Cu. In. l4 GAS DOHC Turbocharged

Index / Table of contents

  • Body
  • Brakes
  • Chassis Electrical
  • Driveline
  • Engine Cooling
  • Engine Electrical
  • Engine Mechanical
  • Engine Performance & Emission Controls
  • Fuel System
  • General Information & Identification
  • Heating, Ventilation, & Air Conditioning
  • Hybrid & Electric Vehicle Systems
  • Steering
  • Suspension
  • Transmission, Clutch, & Transfer Case
  • Wiring Diagrams

Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • Bancontact
  • Google Pay
  • Maestro
  • Mastercard
  • PayPal
  • Union Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

Vehicle Safety Data

2021 Cadillac CT4 Recalls & Complaints

NHTSA #22V90300008/12/2022Component: EXTERIOR LIGHTING:LIGHTING CONTROL MODULE:SOFTWARE

General Motors, LLC (GM) is recalling certain 2020-2023 Cadillac CT4 and CT5; 2021-2023 Buick Envision; and 2022-2023 Cadillac Escalade and Escalade ESV, Chevrolet Silverado 1500, Suburban, Tahoe, GMC

Consequence

DRLs that do not deactivate as intended may result in a glare, reducing visibility, and increasing t

Remedy

The body control module software will be updated by a dealer, or through an over-the-air (OTA) updat

NHTSA #21V61100005/08/2021Component: AIR BAGS:SIDE/WINDOW:CURTAIN

General Motors, LLC. (GM) is recalling certain 2020-2022 Cadillac CT4 and CT5 vehicles. The roof rail side-curtain air bags may not have been installed correctly, which could result in an improper ai

Consequence

Air bags that do not deploy properly can increase the risk of injury in a crash.

Remedy

Dealers will inspect both left and right-side roof rail air bags and reinstall the air bags, as nece

TSB #11032764

Pi created to provide GM dealers with information on gathering information for projection issue

TSB #11032763

This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues

TSB #11031948

This Preliminary information communicates an issue with a replace or low FOB battery message

TSB #11031717

This PI communicates information on a SPS programming issue causing Serial Data Authentication Configuration to fail.

TSB #11030974

This preliminary information communicates information about how to determine if a wheel and tires size change is available.

TSB #11030092

This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a Technical Assistance Case in CX Connect.

TSB #11030091

This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.

TSB #11029950

This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC'ss

Showing the 8 most recent of 804 technical service bulletins on file with NHTSA.

20250827Component: POWER TRAIN

There is a known issue with hesitation and hard shifting on my vehicle. According to the gm bulletin that was released I believe in may of 25 my year, make and model has a known issue where the transm

20250416Component: ENGINE

valve body failed and was supposedly repaired. I had the car 1 day and valve body failed again. My car has been in the shop since November 4, 2024 with no estimated time of repair because no parts ar

20240430Component: ENGINE

Engine and transmission for the second time in 90 days apart. Supposedly be a new part. I don’t think so.

20240430Component: SUSPENSION

Engine and transmission for the second time in 90 days apart. Supposedly be a new part. I don’t think so.

20240124Component: STEERING

While driving the power steering was lost. The the auto hold function lit up. The collision warning light lit up. The stabilitrak system lit up. The air bag safety system lit up. Steering became very

Showing the 5 most serious of 8 complaints filed with NHTSA.

All Model Years

Other Years of the Cadillac CT4

Need a manual for a different year? Browse every Cadillac CT4 we cover.

Explore More

More Cadillac Models

Browse service and repair manuals for other Cadillac models in our catalog.