Code Definition

P1023 — Fuel Pressure/Quantity Too Low at Start

System: Powertrain  |  Type: Manufacturer-Specific  |  Make: Porsche

About P1023

P1023 is a manufacturer-specific powertrain diagnostic trouble code recorded for Porsche vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1023 is stored, the module has detected a signal or supply voltage lower than the expected operating range.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

P1023 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

On this Porsche application the engine control module monitors fuel pressure in the high pressure direct injection system during engine start to ensure enough pressure is available for combustion. The high pressure pump, driven from the camshaft, raises low pressure supply fuel to the much higher pressure needed at the injectors, and a rail pressure sensor provides feedback to the module. DTC P1023 is stored when the module detects that the measured fuel pressure or delivered fuel quantity is below the calibrated threshold during cranking or initial start. This indicates the high pressure fuel...

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