VOLVO
CEM-B1A6321 - Right Solar Sensor. General Signal Failures. Signal too low
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsV40 (2013–), V40 Cross Country (2013–)
Show models by year and engine (2)
What does this fault code mean?
The CEM checks the signal from the right solar sensor. The fault is stored when the signal from the sensor is too low, which is caused by the signal being short-circuited to earth.
Possible causes
- The signal from the right solar sensor is short-circuited to earth
What you can do
- 1Check that the fuses for the climate control are intact
- 2If you have a diagnostic tool, check in live data that the solar sensor value changes when you cover and uncover it
- 3Check the connector at the solar sensor and the wire for chafing and pinch damage
- 4With the connectors disconnected, use a multimeter to check that the signal wire has no contact with earth
- 5If the fault returns, have a workshop check the solar sensor and the control module
Symptoms you may notice2
- The air conditioning does not cool enough in the front part of the cabin
- The climate control does not work as it should
General guidance for car owners. Diagnosis on the car can point to a different cause.