Fault-Code Library · Fuel delivery
P0093: Large fuel-system leak detected
Fuel pressure is dropping at a rate that the ECU interprets as a major leak or excessive internal loss.
Common symptoms
- •Reduced power
- •Hard starting
- •Stalling
- •Fuel smell
Likely causes
- •External fuel leak
- •Excessive diesel injector return flow
- •Pressure-control fault
- •Weak high-pressure pump
First checks
- •Stop and inspect for external leakage
- •Compare requested and actual rail pressure
- •Perform injector return-flow testing
Important
Do not drive or run the engine when an external fuel leak is possible, especially on a high-pressure diesel system.
A fault code identifies a detected condition, not a failed part. Confirm manufacturer-specific subcodes and live data.
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