VOLVO
CRM-20B2 - Hall sensor 3. 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 3 draws more current than normal, and no sensor pulse appears when the hydraulic pump runs. The fault can be caused by a short to ground in the signal wire, a break or disconnected connector between the sensor and the control module, an internal fault in the sensor, or a fault inside the roof control module.
Possible causes
- The signal wire from hall sensor 3 is shorted to ground
- Break in the connection between hall sensor 3 and the roof control module
- Internal fault in hall sensor 3
- Internal fault in the roof control module (CRM)
What you can do
- 1Read out and clear the fault code, test the roof and see whether the fault returns
- 2Check that the connector to hall sensor 3 is clean, fully seated and free from loose connections
- 3With a multimeter you can check whether the wire from the sensor has a break or a short to ground
- 4Repair a damaged wire. If the connector and wire are intact but the fault remains, a workshop should replace hall sensor 3
- 5If the fault still remains, a workshop needs to check the roof control module
Symptoms you may notice2
- No or limited roof operation
- A message appears in the display
General guidance for car owners. Diagnosis on the car can point to a different cause.