VOLVO
CEM-5E02 - Sun sensor. Signal too low
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The central electronic module (CEM) has registered that the circuit to the sun sensor is short-circuited to ground. The sun sensor measures sunlight so the climate system can adjust the cabin temperature, so a fault means the temperature does not match the setting in strong sunlight.
Possible causes
- Faulty sun sensor
- Short to ground in the wiring to the sun sensor
What you can do
- 1Read and clear the code, then check that the climate system reacts when the sun sensor is covered by hand and lit with a flashlight from close range
- 2Check the sun sensor connector for loose connections and corrosion
- 3Use a multimeter to check that the sun sensor wire has no contact with ground (the body)
- 4If the wiring is intact and the fault remains, a workshop should replace the sun sensor
- 5After the repair, road test the car and check that the cabin temperature follows the setting in sunlight
Symptoms you may notice2
- Passenger compartment temperature is not reduced in strong sunlight
- Passenger compartment temperature does not match the set position
General guidance for car owners. Diagnosis on the car can point to a different cause.