VOLVO
CEM-1A5E - Communication with the steering wheel angle sensor module (SAS). Signal missing
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
What does this fault code mean?
The central electronic module (CEM) has lost the link to the steering wheel angle sensor (SAS) and sets this code. The fault lies in the communication, not in the CEM, so the CEM should not be replaced. The SAS sits inside the steering wheel module and measures the angle that the stability system uses, so without its signal the stability function does not work.
Possible causes
- The SAS is not getting power
- The ground wire to the SAS is broken
- Contact resistance in the connections
- Broken CAN wiring to the SAS
- Wrong SAS for this car, for example a used module with different software or hardware
- No power or ground reaching the steering wheel module, since the SAS is supplied from it
What you can do
- 1With the ignition on, the DSTC lamp in the climate control button row should light.
- 2Check the SAS fuse. If it has blown, replace it once. If it blows again, use a multimeter to check the wire after it has no contact with ground.
- 3Check that the connector to the steering wheel module is seated and not corroded. Use a multimeter to check that its ground wire has no break
- 4With a diagnostic tool, watch the steering angle in live data; it should change evenly lock to lock. Do not work on the steering wheel module yourself
- 5After the work, DSTC is not activated until the car has reached a certain speed, so road-test the car afterwards
Symptoms you may notice4
- The anti-spin lamp is lit (model year 2002 and earlier)
- The general yellow warning lamp is lit (model year 2003 and later)
- The stability function does not work
- A message appears in the display
General guidance for car owners. Diagnosis on the car can point to a different cause.