Every control module on the 2020-2026 Cadillac CT4-V — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
Transmission Control Module (TCM) 2.5 hr R&R security gateway +1.0 hr ▸ programming details
📍 Integrated into transmission assembly, driver side of 10-speed automatic
🔧 GDS2 via Techline Connect
⚠️ Requires transmission fluid drain; adaptive learning reset required after programming
Body Control Module (BCM) 2.0 hr R&R security gateway +1.2 hr ▸ programming details
📍 Behind instrument panel, center stack area above center console
🔧 GDS2 via Techline Connect
⚠️ Controls lighting, door locks, windows; extensive configuration required for vehicle options
Gateway Module (GM) 1.8 hr R&R security gateway +1.0 hr ▸ programming details
📍 Behind instrument panel, center area near BCM
🔧 GDS2 via Techline Connect
⚠️ Security gateway; controls access to other modules; critical for network communication
Electric Power Steering Control Module (EPSCM) 1.8 hr R&R security gateway +0.8 hr ▸ programming details
📍 Steering column assembly, below instrument panel
🔧 GDS2 via Techline Connect
⚠️ Steering angle sensor calibration required after replacement
Active Chassis Control Module (ACCM) 1.8 hr R&R dealer / factory tool +1.0 hr ▸ programming details
📍 Engine compartment or under vehicle, center mounted
🔧 GDS2 via Techline Connect
⚠️ Performance traction management system; V-Series specific; calibration required
Surround Vision Camera Module (SVCM) 1.5 hr R&R dealer / factory tool +0.8 hr ▸ programming details
📍 Behind rearview mirror or center stack area
🔧 GDS2 via Techline Connect
⚠️ Processes multiple camera inputs; rear vision and surround view; calibration required
Electronic Brake Control Module (EBCM) 1.5 hr R&R dealer / factory tool +0.8 hr ▸ programming details
📍 Engine compartment, driver side near brake master cylinder
🔧 GDS2 via Techline Connect
⚠️ Brake system bleed required after replacement; integrates ABS, traction control, and stability control
Heating, Ventilation and Air Conditioning Control Module (HVAC) 1.5 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Behind instrument panel, center stack integrated with climate controls
🔧 GDS2 via Techline Connect
⚠️ Dual-zone automatic climate control; configuration for vehicle options required
Infotainment Control Module (ICM) 1.5 hr R&R dealer / factory tool +0.8 hr ▸ programming details
📍 Center stack, integrated with 8-inch or 10-inch touchscreen display
🔧 GDS2 via Techline Connect
⚠️ Cadillac User Experience (CUE) system; Apple CarPlay/Android Auto integration
Magnetic Ride Control Module (MRCM) 1.5 hr R&R dealer / factory tool +0.8 hr ▸ programming details
📍 Rear cargo area or under rear seat, center mounted
🔧 GDS2 via Techline Connect
⚠️ Optional on CT4-V; adaptive damping system; calibration required after replacement
Parking Assist Control Module (PACM) 1.2 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Rear cargo area, behind rear trim panel
🔧 GDS2 via Techline Connect
⚠️ Ultrasonic parking sensors; front and rear detection
Instrument Panel Cluster (IPC) 1.2 hr R&R security gateway +0.8 hr ▸ programming details
📍 Instrument panel, behind steering wheel
🔧 GDS2 via Techline Connect
⚠️ Digital cluster; VIN and mileage programming required; odometer transfer mandatory
Engine Control Module (ECM) 1.2 hr R&R security gateway +1.0 hr ▸ programming details
📍 Engine compartment, driver side firewall area, mounted to bulkhead
🔧 GDS2 via Techline Connect
⚠️ VIN programming and security gateway unlock required; 2.7T and 3.6L V6 engines
Fuel Pump Control Module (FPCM) 1.2 hr R&R relearn only +0.3 hr ▸ programming details
📍 Rear of vehicle, near fuel tank or integrated with fuel pump assembly
🔧 GDS2 or Autel MaxiSys
⚠️ Fuel tank access required; adaptive fuel pressure relearn after replacement
Sensing and Diagnostic Module (SDM) 1.0 hr R&R security gateway +0.5 hr ▸ programming details
📍 Center console area, below center stack or under front seats
🔧 GDS2 via Techline Connect
⚠️ Battery disconnect and 2-minute wait required; VIN programming mandatory
Door Control Module (DCM) 1.0 hr R&R aftermarket tool +0.3 hr ▸ programming details
📍 Inside door panels, all four doors
🔧 GDS2 or Autel MaxiSys
⚠️ Power windows, mirrors, locks; four modules total
Remote Control Door Lock Receiver (RCDLR) 1.0 hr R&R security gateway +0.8 hr ▸ programming details
📍 Behind instrument panel, driver side or center stack area
🔧 GDS2 via Techline Connect
⚠️ Keyless entry/start system; key fob programming required after replacement
OnStar Communication Module (VCIM) 1.0 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Behind headliner, above rearview mirror or rear cargo area
🔧 GDS2 via Techline Connect
⚠️ OnStar subscription reactivation required; 4G LTE connectivity
Headlamp Control Module (HCM) 0.8 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Behind headlamp assemblies, driver and passenger side engine compartment
🔧 GDS2 via Techline Connect
⚠️ LED headlamps; automatic high beam and adaptive lighting features
Rear Radar Sensor Module (RRSM) 0.8 hr R&R dealer / factory tool +0.8 hr ▸ programming details
📍 Rear bumper, driver and passenger side corners
🔧 GDS2 via Techline Connect
⚠️ Blind spot monitoring and rear cross traffic alert; two modules; calibration required
Seat Control Module (SCM) 0.8 hr R&R aftermarket tool +0.3 hr ▸ programming details
📍 Under front seats, driver and passenger side
🔧 GDS2 or Autel MaxiSys
⚠️ Power seat memory and heating/ventilation functions; two modules (driver/passenger)
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour?
Tell us — corrections ship fast here.