A temperature-related fault needs a clear description. Is the vehicle genuinely overheating, displaying an implausible reading, or reporting an electrical circuit code? These are different observations. Follow any stop-engine instruction; do not treat an overheating warning as harmless because a sensor is suspected.
Identify the recorded fault
P0115 concerns the engine-coolant temperature circuit. P0118 describes a high input in that circuit. A high electrical input is not the same statement as a high measured coolant temperature.
Code descriptions HELLA generic diagnostic-code reference. Confirm the full code, suffix and test procedure against the exact vehicle.
Why temperature information matters
HELLA explains that engine management uses coolant-temperature information to adjust injection and ignition. Its guidance also distinguishes wiring faults and implausible signals from an engine that fails to reach its expected temperature; a thermostat can be relevant to the latter. Source HELLA coolant-temperature sensor guidance.
Describe the pattern clearly
Record what the dashboard showed, the exact warning and whether the concern appeared immediately after a cold start or after driving. Include any existing diagnostic temperature readings with units and test conditions. Say whether the heater behaviour, fan operation or starting changed, without assuming those observations identify the failed part.
List recent cooling-system work, sensor changes, engine repairs or electrical work. If a workshop has supplied a temperature or circuit test, attach the report. A single disconnected-sensor reading should not be confused with a normal operating measurement.
What to ask the diagnosing workshop
Ask whether its evidence points to an actual thermal problem, a sensor or wiring concern, or controller input processing. Request the vehicle-specific test result that supports the proposed repair. Do not open a hot cooling system or probe live circuits to gather information for an enquiry.
Use electrical diagnostics for an identified electrical concern. Mechanical cooling-system repairs may require a separate scope; an ECU bench assessment does not replace checks on the complete vehicle.
AXION Automotive handles specialist electronics enquiries from Didcot and UK garages. Use our assessment checklist, then send the vehicle details and scan report. Vehicle and component support must be confirmed before booking or posting a unit.