Mercedes-benz P179a12

Sometimes a faulty brake pedal switch can prevent the shifter from releasing, which can be mistaken for an ISM fault. How to Fix the P179A12 Fault

When the computer detects that the ISM (Shift Module) is not responding correctly or has a short circuit, it throws this code. The "redundancy system" activation means the car has detected a fault and is attempting to prevent unsafe gear selection, often by locking the car in Park. Commonly Affected Models mercedes-benz p179a12