VOLVO
CRM-20A1 - Hall sensor 1. 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 1 draws less current than normal, and when the hydraulic pump for the roof starts, no signal comes from the sensor. This points to the wire between the sensor and the roof control module being shorted to voltage. The roof may then not move as it should.
Possible causes
- Short to voltage in the wire from hall sensor 1 to the roof control module
- Damaged hall sensor
- Fault inside the convertible roof 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
- 2Look at the connector at hall sensor 1 and check that it is fully seated and free from oxidation
- 3With a multimeter you can check that the wire from hall sensor 1 has no contact with voltage
- 4If no fault is found in the wire, hall sensor 1 may be damaged and a workshop should replace it
- 5If the fault remains, a workshop needs to check the roof control module
Symptoms you may notice2
- The roof cannot be operated, or only moves partly
- A message in the display
General guidance for car owners. Diagnosis on the car can point to a different cause.