The database covers 83 dealer codes — Weichai/Shaanxi WP10/WP12 uses its own factory format, outside the J1939 SPN/FMI standard. A few examples below; look up your own code in the search on the homepage, where you can also pick “Weichai/Shaanxi WP10/WP12” from the brand list.
| 111 | ECU analog-to-digital converter fault — engine will not start. Replace the ECU. |
| 116 | Insufficient engine power. Cut power and reset the ECU; if the fault persists, replace the ECU. |
| 131 | ECU internal sensor supply module fault — engine power may be insufficient. ECU fault, or the boost pressure sensor (2.33) / oil pressure sensor (2.32) supply shorted to vehicle supply (24V) or to ground, or the accelerator pedal sensor No.2 supply (1.84) shorted. Check the harnesses of these sensors (maximum supply current 90 mA). |
| 136 | Rail pressure relief valve — heavy valve wear causes abnormal rail pressure fluctuation. Blocked low-pressure lines (fuel supply and return) make the valve open often or stay open too long. Replace the rail. |
| 146 | Cylinder 6 injector fault — insufficient/unstable engine power (rough running). Poor injector harness contact or open wiring. Check the injector wiring and its connection. |
| 155 | Injector delivery limited by the ECU. |
| 227 | Engine protection — triggered when engine speed goes above 2650 rpm. |
| 233 | Intake air temperature sensor fault. Check the sensor harness, replace the sensor if necessary. |
| 251 | High-pressure or low-pressure fuel line — leakage. Hard starting or no start, the pressure limiting valve opens and a large amount of high-pressure fuel leaks. Fuel supply resistance too high or a leak, fuel return resistance too high. Check the engine fuel lines, replace the filters and the fuel line if necessary. |
| 256 | High-pressure or low-pressure fuel line — leakage. Hard starting or no start, the pressure limiting valve opens and a large amount of high-pressure fuel leaks. Fuel supply resistance too high or a leak, fuel return resistance too high. Check the engine fuel lines, replace the filters and the fuel line if necessary. |
| 265 | EEPROM fault — mileage data cannot be recorded. Replace the ECU. |
| 322 | Intake air heater relay fault — the intake heater does not work properly. Relay shorted to ground or to supply. Check the intake heater relay wiring. |
| 333 | Warning lamp connection fault. |
| 511 | Cylinder 1 cutout test — insufficient/unstable engine power. Check the injector, cylinder head gasket, valve clearance, etc. for cylinder 1. |
| 523 | External measurement — a function indication, not a failure. The flash code is stored when the internal ECU measuring function is activated with a diagnostic tool and the measurement succeeds. |
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