P0115 on Citroën — Coolant boiling at high speed with the coolant warning light on
Code P0115 indicates a generic fault on the engine coolant temperature sensor. On the Citroën Jumper 2.0 HDI it appears when, at high speed, the coolant boils and the temperature climbs to its maximum reading.
- System
- Engine cooling
- Component
- Water pump
- Fault
- At high speed the coolant boils: the engine temperature gauge reaches its maximum reading and the red coolant temperature light comes on. Reducing speed brings the gauge down and the light goes out.
- Typical symptoms
-
- The coolant boils while driving at high speed
- Engine temperature gauge at its maximum reading
- Red coolant temperature light on
- Reducing speed brings the temperature back down and the light goes out
- The vehicle otherwise continues to run normally
- Vehicles affected
-
- Citroën Jumper (U9) 2.0 HDI 16v
- Main code
-
- P0115 Engine coolant temperature sensor, generic fault
- Solution
-
See the repair procedure verified on Sema Repair.
The cause and the repair are on Sema Repair
On Sema Repair this code is linked to verified case studies, with the confirmed cause case by case, the job step by step, indicative times, the manufacturer's notes and a photograph of the component with the point of intervention highlighted.
Frequently asked questions about P0115
P0115 names the temperature sensor: should it be replaced?
In this case the sensor is correctly measuring a temperature that really is high. The code reports the out-of-range value, not a faulty sensor: replacing it will not bring the temperature down.
Why does the temperature only rise at high speed?
Because it is at maximum demand that coolant circulation has to be at full flow; at lower speed less heat is produced and the fault does not show. The fact that it settles when you slow down is a precise diagnostic clue.
Can the journey be continued by driving slowly?
That is the quickest way to turn a fault into an engine rebuild. With the red temperature light on, the vehicle must be stopped.