Every control module on the 2020-2026 Mercedes-Benz CLA250 C118 — 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 Unit (TCU) 2.5 hr R&R security gateway +1.0 hr ▸ programming details
📍 Transmission housing, driver side near valve body (7G-DCT or 8G-DCT)
🔧 Xentry Diagnostics + SCN online
⚠️ Requires transmission oil change after replacement. VIN-locked, SCN coding mandatory.
Electric Power Steering Control Unit (EPS) 2.0 hr R&R security gateway +1.0 hr ▸ programming details
📍 Steering column, integrated with steering rack assembly
🔧 Xentry Diagnostics + SCN online
⚠️ Steering angle sensor calibration required after replacement. VIN-locked.
MBUX Head Unit (MBUX/HU) 2.0 hr R&R dealer / factory tool +1.0 hr ▸ programming details
📍 Center dashboard, integrated touchscreen unit
🔧 Xentry Diagnostics + SCN online
⚠️ Requires MBUX software installation and vehicle configuration coding. Navigation data transfer needed.
Electronic Stability Program Control Unit (ESP/ABS) 1.8 hr R&R security gateway +1.0 hr ▸ programming details
📍 Engine compartment, left front near fender
🔧 Xentry Diagnostics + SCN online
⚠️ Integrated hydraulic unit. Requires brake bleed after replacement. VIN-locked.
Climate Control Unit (CCU) 1.5 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Behind center dashboard, above center console
🔧 Xentry Diagnostics
⚠️ Requires HVAC system adaptation and actuator calibration after replacement.
Electronic Ignition Switch (EIS) 1.5 hr R&R security gateway +1.5 hr ▸ programming details
📍 Steering column, upper shroud near ignition slot
🔧 Xentry Diagnostics + SCN online + key programming
⚠️ Part of immobilizer triangle (EIS-ECM-IC). All keys must be reprogrammed. Critical security module.
Motor Electronics / Engine Control Unit (ME/ECU) 1.2 hr R&R security gateway +1.0 hr ▸ programming details
📍 Engine compartment, left side firewall near brake booster
🔧 Xentry Diagnostics + SCN online
⚠️ VIN-locked, requires online SCN coding and EIS pairing. Immobilizer triangle must be maintained.
Central Gateway Module (CGW) 1.2 hr R&R security gateway +1.5 hr ▸ programming details
📍 Under dashboard, center behind lower trim panel
🔧 Xentry Diagnostics + SCN online
⚠️ Security gateway enforces authentication. Replacement requires full vehicle reconfiguration.
Radar Sensor / DISTRONIC Control Unit (RSU) 1.2 hr R&R security gateway +1.0 hr ▸ programming details
📍 Front bumper, center behind grille emblem
🔧 Xentry Diagnostics + SCN online + radar alignment tool
⚠️ Adaptive cruise control and collision prevention. Requires precise radar alignment after replacement.
Rear Signal Acquisition and Actuation Module (SAM-R) 1.0 hr R&R security gateway +1.0 hr ▸ programming details
📍 Trunk, left side behind trim panel
🔧 Xentry Diagnostics + SCN online
⚠️ Controls rear lighting, fuel pump relay, trailer functions if equipped.
Camera Control Unit / Surround View (CCU) 1.0 hr R&R dealer / factory tool +0.8 hr ▸ programming details
📍 Trunk, right side behind trim panel or integrated in MBUX head unit
🔧 Xentry Diagnostics
⚠️ Backup camera and 360-degree camera system. Requires camera calibration and alignment.
Instrument Cluster (IC) 1.0 hr R&R security gateway +1.0 hr ▸ programming details
📍 Dashboard, behind steering wheel
🔧 Xentry Diagnostics + SCN online
⚠️ VIN-locked, mileage programming requires dealer authorization. Part of immobilizer triangle.
Intelligent Light System Control Unit (ILS) 1.0 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Each headlight assembly, integrated in LED headlamp housing
🔧 Xentry Diagnostics
⚠️ Adaptive LED headlights. Requires headlight range calibration and beam pattern adaptation.
Tailgate Control Module (TGM) 1.0 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Trunk lid, integrated in power liftgate mechanism (if equipped)
🔧 Xentry Diagnostics
⚠️ Only on vehicles with power trunk. Requires position calibration after replacement.
Restraint Systems Control Unit (SRS) 0.8 hr R&R security gateway +0.8 hr ▸ programming details
📍 Center console, under front seats mounting bracket
🔧 Xentry Diagnostics + SCN online
⚠️ Battery must be disconnected 10+ minutes before removal. VIN-locked, crash data stored.
Adaptive Damping System Control Unit (ADS) 0.8 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Trunk, right side behind trim panel or under rear seat
🔧 Xentry Diagnostics
⚠️ Only on vehicles with adaptive suspension. Requires ride height calibration if equipped.
Door Control Module (DCM) 0.8 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Inside each door, behind door panel (up to 4 modules)
🔧 Xentry Diagnostics
⚠️ Controls window, mirror, lock, puddle lights. Window initialization required after replacement.
Blind Spot Assist Control Unit (BSA) 0.8 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Rear bumper, left and right corners (integrated in radar sensors)
🔧 Xentry Diagnostics
⚠️ Blind spot monitoring. May be integrated into main radar module or separate rear radar sensors.
Telematics Communication Module (TCM) 0.8 hr R&R security gateway +0.8 hr ▸ programming details
📍 Trunk, right side behind trim panel or under rear shelf
🔧 Xentry Diagnostics + SCN online
⚠️ Mercedes me connect services. Requires online activation and subscription transfer.
Fuel Pump Control Module (FPCM) 0.6 hr R&R aftermarket tool +0.3 hr ▸ programming details
📍 Trunk, left side near fuel tank or integrated in SAM-R
🔧 Xentry Diagnostics or Autel
⚠️ May be integrated into SAM-R on some variants. Simple adaptation usually sufficient.
Parktronic Control Unit (PTS) 0.6 hr R&R dealer / factory tool +0.3 hr ▸ programming details
📍 Trunk, center behind trim panel near bumper
🔧 Xentry Diagnostics
⚠️ Parking sensors. Requires sensor calibration after replacement.
Seat Control Module (SCM) 0.5 hr R&R dealer / factory tool +0.5 hr ▸ programming details
📍 Under each front seat, driver and passenger side
🔧 Xentry Diagnostics
⚠️ Controls power seat, memory, heating, ventilation. Separate module per seat if equipped.
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?
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