Volvo Engine D12D AE E3 (Tier 3) Fault Code: SID21 FMI 8 Engine Position

DETECTION CONDITIONS:
The engine control unit (E-ECU) registers that frequency of the signal from the sensor is abnormal. (EA45/EA46)

SYMPTOM:
Difficult to start at next start attempt (no symptom if error code is generated when engine is running).

POSSIBLE CAUSES:
1. Electric interference on speed signal.
2. Poor insulation or defective cable.
3. Incorrectly installed sensor (incorrect distance to sensor gear).
4. Defective sensor.
5. Defective sensor gear.