4B9-4 1221 2
UnclassifiedFuel
What This Code Means
No response or an erroneous response is detected by the processor; Needed fuel flow exceeds a maximal expected fuel flow by more than a fuel flow dependent value (15700,00mm3/s at 4500,00mm3/s to 14000,00mm3/s at 14330,00mm3/s); Supply voltage does not drop below limit within 500,00ms after the request of 'Main Relay switch off'; ECU cannot perform After-run actions (storage of failures into memory, counting of driving cycles, and corresponding pending/validated/long-time failure reactions)
Possible Causes
- •Communication failure between ECM processor and power stage controller over SPI bus
- •Leakage in the fuel system
- •Main relay is stuck in closed position
- •Main relay switches off before the After-run has finished
Related Winco Fault Codes
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