1999 Mercedes-Benz S420 Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 1999 Mercedes-Benz S420
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1999 Mercedes-Benz S420 ProblemsFaulty Mass Air Flow Sensor Causing Erratic Engine Operation and Poor Fuel Economy
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.
Problems with the pneumatic system can cause closing assist and door lock issues.
1999 Mercedes-Benz S420 Questionsthere is cable at the back side at the end of the transmission that is leaking ? (1 answer)
had to remove the transmission cross member to get to it
I am trading in my 1999 MB S420 for a new car, but not a new Mercedes. My dash lights just came on and I don't want to trade in the car with the warning lights on. Can I temporarily turn them off? Thank you.