VOLVO
CEM-3F83 - Immobilizer signal. Signal too low
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 CEM receives a signal from the gearbox that park or neutral is engaged, and compares it with the gear position from the TCM over the CAN network. If they do not match, the code is set. The gear position lock may then not work.
Possible causes
- The cable from the gear position sensor is shorted to ground
What you can do
- 1With the ignition off, check that the connectors at the gear position sensor and the CEM are seated and not corroded
- 2Use a multimeter to check that the cable from the gear position sensor is not shorted to ground
- 3With a diagnostic tool, follow the gear position sensor position in live data while you move the gear selector through the positions
- 4After the work, clear the code and check that the gear position lock works
Symptoms you may notice1
- The gear position lock does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.