VOLVO
CRM-20A2 - Hall sensor 1. Short to GND, disconnected or internal error
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 1 draws more current than normal, and no sensor pulse appears when the hydraulic pump for the roof runs. The fault can be caused by the signal wire being shorted to ground, by a broken connection between the sensor and the control module, or by an internal fault in the sensor or in the roof control module.
Possible causes
- The signal wire is shorted to ground
- Broken connection between hall sensor 1 and the roof control module
- Internal fault in hall sensor 1
- 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 to hall sensor 1 is clean, fully seated and free from corrosion
- 3With a multimeter you can check whether the wire from the sensor has a break or a short to ground
- 4If a damaged wire is repaired the fault may clear; otherwise hall sensor 1 may need replacing by a workshop
- 5If the fault still remains, a workshop needs to check the roof control module
Symptoms you may notice2
- The roof cannot be operated at all, or only to a limited extent
- Message in the text display
General guidance for car owners. Diagnosis on the car can point to a different cause.