BMW E46 M3 P1115 Coolant Temperature Sensor Plausibility Error - Diagnosis and Fixes

Model: BMW 2001 M3 Fault Code: P1115 Posted: 2011-06-02 19:13

I'm currently receiving the P1115 diagnostic code on my BMW 2001 E46 M3, which indicates a 'coolant temperature sensor plausibility' fault. I've already replaced both the coolant temperature sensor located in the lower radiator hose and the one situated under the throttle body on the engine block. Despite these replacements, the code persists. The vehicle runs smoothly, does not overheat, and has normal oil temperatures. I've also recently replaced the coolant cap. Given that the car is due for emissions testing soon, I'm seeking advice on whether there could be other components or sensors contributing to this issue—such as a faulty thermostat, wiring harness problems, or sensor circuit issues. Any insights would be greatly appreciated.