1994 Mercedes-Benz S420 Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 1994 Mercedes-Benz S420
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1994 Mercedes-Benz S420 ProblemsClosing Assist/Door Lock Issues Due to Pneumatic System Problems
Problems with the pneumatic system can cause closing assist and door lock issues.
A faulty mass air flow (MAF) sensor can cause erratic/rough engine operation and fuel economy issues. Since this sensor measures the actual amount of air entering the motor, when it fails, the engine control module (ECM) takes the wrong information and delivers incorrect volumes of fuel to the cylinders.
The engine wiring can degrade because the insulating material falls off leaving the bare wire exposed. This can cause many problems depending on which wires are exposed and what they touch.
1994 Mercedes-Benz S420 Questionshow to bypass security car wont start. cranks but security lights flash and it inhibits it from starting. driver door not closing (1 answer)
little air comes through vents but no heat????