4B9-4
What This Code Means
No response or an erroneous response is detected by the processor over the SPI bus; 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'; Main relay switches off before the After-run has finished; ECU fails to store failures into memory; ECU fails to count driving cycles and perform corresponding reactions; Electric failure in the fuel metering unit (MeUn) power stage at Low Side; Electric failures in the control lamp for Glow Plug activation; Actual boost pressure is higher than target boost pressure beside a defined threshold; Underboost; Positive boost pressure deviation; Electric failure in the power stage of Bitron actuator; Electric failure in the power stage of VGT actuator; Turbine upstream pressure Signal Range Errors; No response from power stage controller; Erroneous
Possible Causes
- •Communication failure between ECM processor and power stage controller over SPI bus
- •Leakage in the fuel rail pressure control system
- •Main relay is stuck in closed position
- •Main relay switches off prematurely before ECU finishes After-run actions
- •Fuel metering unit to common rail (MeUn) hardware detected electrical failure (voltage or current deviation)
- •Power stage for the control lamp for Glow Plug activation hardware detected electrical failure
- •Boost pressure value monitoring failure
- •Deviation of actual boost pressure from target pressure while the engine is running within the specified working area
- •Power stage of Bitron actuator hardware detected electrical failure
- •Power stage of VGT or Bitron actuator hardware detected electrical failure
- •Out of range raw voltage signal (Exh_uRawPTrbnUs) acquired via hardware connected turbine upstream pressure sensor
- •SPI bus communication failure between ECM processor and power stage controller
Related Winco Fault Codes
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