VOLVO
CEM-5E03 - Sun sensor Signal too high
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 a fault in the circuit to the second sun sensor, either a short to battery voltage or an open circuit. The second sun sensor also measures sunlight, so a fault affects the cabin temperature and the air conditioning.
Possible causes
- Defective sun sensor 2
- Open circuit or short to battery voltage 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 connector to the sun sensor for loose connections and corrosion
- 3Use a multimeter to check that the wire to sun sensor 2 is not broken and has no contact with battery voltage
- 4If the wiring is intact and the fault remains, a workshop should replace the sun sensor
- 5Check that the air conditioning works properly 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 properly
General guidance for car owners. Diagnosis on the car can point to a different cause.