This is the single most common cause. Over years of use, the tiny spring-loaded microswitches inside the manual handbrake control unit wear out or get gummed up with dust. When you manipulate the handle, the failing microswitch lags or fails to close, triggering the "signal incoherence" error.
This article dives deep into what the DF045 code means on a Renault Scenic, its symptoms, root causes, diagnostic steps, and the exact cost to fix it.
Check the back of the small circuit board under a magnifying glass. Refresh any hairline cracks on the pin solders with a standard soldering iron. Alternative Scenario: Engine MAP Sensor Issue
