VOLVO
CEM-5E04 - 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 second sun sensor is short-circuited to ground. The sun sensor is used so the climate system can match the cabin temperature to the sunlight, so a fault means the temperature and air conditioning do not work as they should.
Possible causes
- Defective sun sensor 2
- Short to ground in the wiring to sun sensor 2
What you can do
- 1Read and clear the code, then check whether the climate system reacts when the second sun sensor is covered by hand and lit with a flashlight
- 2Check the sun sensor connector for loose connections and corrosion
- 3Use a multimeter to check that the wire to sun sensor 2 has no contact with ground (the body)
- 4If the wiring is intact and the fault remains, a workshop should replace the sun sensor
- 5Check that the air conditioning works after the repair
Symptoms you may notice3
- Passenger compartment temperature is not reduced in strong sunlight
- Passenger compartment temperature does not match the set position
- Temperature control and air conditioning do not work
General guidance for car owners. Diagnosis on the car can point to a different cause.