VOLVO
CRM-20C1 - Hall sensor 18. Shorted to supply
System
Chassis (Brakes, Steering, Suspension)
Volvo models this fault code applies to
Applies to the following models:
1 modelC70 (2006–2013)
Show models by year and engine (1)
What does this fault code mean?
Hall sensor 18 draws less current than normal, and when the hydraulic pump for the roof is activated there is no sensor pulse. The cause may be the signal wire from the sensor to the roof control module being shorted to voltage. The roof may then not move as it should.
Possible causes
- The signal wire between hall sensor 18 and the roof control module is shorted to voltage
- Damaged hall sensor
- Internal fault in the roof control module (CRM)
What you can do
- 1Read out and clear the fault code, test the roof in both directions and see whether the fault returns
- 2Check that the connector at hall sensor 18 is fully seated and free from oxidation
- 3With a multimeter you can check that the signal wire has no contact with voltage
- 4If no fault is found in the wire, hall sensor 18 may be damaged and need replacing by a workshop
- 5If the fault remains, a workshop needs to check the roof control module
Symptoms you may notice2
- The roof cannot be operated, or only partly
- Message in the text display
General guidance for car owners. Diagnosis on the car can point to a different cause.