Fitment notes: High CCA requirement for diesel engine; battery located in engine compartment
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Every control module on the 1986-1987 Mercedes-Benz 300SDL — where it lives, replacement time, and what it takes to program a replacement.
Instrument Cluster (IC)2.5 hr R&Rno coding
📍 Dashboard behind instrument panel
⚠️ Electromechanical cluster with electronic odometer module. Odometer is separate serviceable component. No coding required but mileage must be documented per federal law when replacing odometer unit.
Diesel Electronic Control (DEC)1.2 hr R&Rrelearn only +0.3 hr▸ programming details
📍 Engine compartment, left side firewall near brake booster
🔧 Idle speed adjustment via potentiometer; fault code retrieval via jumper wire an
⚠️ Bosch electronic diesel control for OM603 turbo engine; limited electronic control compared to gasoline ECUs of era. Primarily controls injection pump rack position and boost pressure. Idle speed learned via mechanical adjustment screw on module. No true programming capability.
Cruise Control Amplifier (CCA)0.8 hr R&Rno coding
📍 Engine compartment, left side firewall near vacuum reservoir
⚠️ Vacuum-actuated cruise control with electronic amplifier. Purely analog control circuit with no digital programming. Adjustment via cable linkage only.
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 1987 Mercedes-Benz 300SDL 3.0L I6 Diesel Turbo and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.