Volvo Engine D12D AE E3 (Tier 3) Fault Code: SID4 FMI 7 Injector #4

DETECTION CONDITIONS:
The engine control unit (E-ECU) registers:
1. Injector activated.
2. Cylinder balancing data above limit.

SYMPTOM:
1. Low power.
2. Engine runs rough/varying engine speed.
3. Abnormal sound.
4. Injector in question is shut off.

POSSIBLE CAUSES:
1. Defect injector.
2. Poor compression.
3. Air in fuel at injector.