P3625moderate severityPowertrain
Dynamic Skip Fire (DSF) Control Module Communication Error
on 2019 Mazda Mazda3 2.5L I4 · FWD
What this code means
The Dynamic Skip Fire control module that selectively fires individual cylinders based on demand has a communication fault with the PCM.
Symptoms
- Check Engine Light
- DSF system disabled
- Constant all-cylinder firing
- Reduced fuel economy
- Engine may vibrate more than usual
- No smooth cylinder deactivation transitions
Common causes
- CAN bus communication fault
- DSF module failure
- PCM DSF driver circuit issue
- Wiring harness damage
- Software version mismatch
Diagnostic steps
- Check communication between DSF module and PCM
- Read DSF module fault codes
- Inspect CAN bus wiring to DSF module
- Verify software versions match
- Test DSF module power supply
Repair notes
Repair CAN bus wiring. Replace DSF module if internal fault. Update software if version mismatch detected.
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