Fitment notes: AGM battery required for start-stop system; located under hood on right side
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Every control module on the 2020-2026 Mercedes-Benz GLB — 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&Rsecurity gateway +1.0 hr▸ programming details
📍 Transmission housing or adjacent to transmission tunnel
🔧 Xentry Diagnostics + SCN online
⚠️ VIN-locked, adaptive values must be reset after replacement
Climate Control Unit (CCU)2.0 hr R&Rdealer / factory tool +0.5 hr▸ programming details
📍 Behind center dashboard, integrated with HVAC unit
🔧 Xentry Diagnostics
⚠️ Requires variant coding for specific vehicle equipment
Signal Acquisition and Actuation Module - Rear (SAM-R)1.8 hr R&Rsecurity gateway +1.5 hr▸ programming details
📍 Right rear cargo area, behind trim panel
🔧 Xentry Diagnostics + SCN online
⚠️ VIN-locked, controls rear lighting and convenience functions
Electric Power Steering Control Unit (EPS)1.5 hr R&Rsecurity gateway +1.0 hr▸ programming details
📍 Steering column or rack housing
🔧 Xentry Diagnostics + SCN online
⚠️ VIN-locked, steering angle sensor calibration required after replacement
MBUX Head Unit (HU/MBUX)1.5 hr R&Rdealer / factory tool +1.0 hr▸ programming details
📍 Center dashboard, integrated with display screen
🔧 Xentry Diagnostics + SCN online
⚠️ Requires online activation and variant coding, navigation data transfer if equipped
4MATIC Control Unit (4M)1.5 hr R&Rdealer / factory tool +0.8 hr▸ programming details
📍 Near transfer case or transmission tunnel
🔧 Xentry Diagnostics
⚠️ Only on 4MATIC equipped models, requires drivetrain configuration coding
Door Control Module (DCM)1.2 hr R&Raftermarket tool +0.3 hr▸ programming details
📍 Inside door panels, typically front doors
🔧 Xentry or Autel
⚠️ Window initialization required after replacement, separate modules per door
Motor Electronics / Engine Control Unit (ME/ECU)1.2 hr R&Rsecurity gateway +1.0 hr▸ programming details
📍 Engine compartment, left side firewall or top of engine
🔧 Xentry Diagnostics + SCN online
⚠️ VIN-locked, requires online SCN coding and component protection authorization from Mercedes servers
⚠️ Separate modules for driver and passenger seats if equipped with memory
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.
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 2025 Mercedes-Benz GLB 2.0L Turbo I4 and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Mechanic · 20+ years.