VOLVO
CRM-C021 - Convertible Roof Module (CRM). Internal fault
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?
Although the fault is labelled an internal fault in the control module, it relates to the supply voltage for several sensors. The code is only set when the supply to the sensors is switched off. The sensors are supplied in groups, so a short to supply voltage in one group's supply can cause the fault. The battery may then discharge and messages may appear in the display.
Possible causes
- The supply voltage to sensors 6 and 18, or to sensors 1, 5 and 10, is shorted to supply voltage
- The sensors are supplied in groups, and one group has a fault
- Internal fault in the roof control module (CRM)
What you can do
- 1Read out and clear the fault code and check whether it returns
- 2With a multimeter you can check that the supply wires to the faulty group have no contact with voltage
- 3Look at the connectors to the sensors in that group for oxidation and loose connections
- 4Replace a faulty wire. If nothing is found, a workshop should replace the convertible roof module (CRM)
Symptoms you may notice2
- Message in the display
- The battery discharges
General guidance for car owners. Diagnosis on the car can point to a different cause.