Reductant pressure is too high when the pump is not running.
1. Use the diagnostic tool to run the reductant circuit test. 2. If the reductant pressure sensor gives a value higher than the normal pressure plus a calibrated hysteresis level at the end of the zero pressure phase of the test, the test will fail. 3. Disconnect the return hose at the top of the reductant tank. Use the diagnostic tool to monitor the reductant pressure. If the pressure decreases when the return hose is disconnected there may be a blockage in the return pipe in the reductant pick-up unit. 4. If the pressure remains, disconnect the return hose at the dosing unit. Be careful, the reductant pressure may be high. Use the diagnostic tool to monitor the reductant pressure. If the pressure decreases when the return hose is disconnected there may be a blockage in the return hose. 5. If the pressure remains, check the harness and connectors between the EEC and the reductant pressure sensor in the dosing unit for electrical failure. 6. If no electrical failure in the harness or connectors are found, flush the doing unit with water. If the error remains change the dosing unit. If a failure has been found and corrected, use the reductant circuit test to check that the system is working and to inactivate the fault code.
What you'll see
This failure could affect reductant dosing accuracy and emissions
System reaction
No system-reaction text recorded.
Diagnostic depth
The reductant pressure sensor (V117 )gives a value larger than the normal pressure plus a calibrated hysteresis level when the pump has not been running for the time needed to evaluate the fault.
Broken reductant pressure sensor. Electrical failure at the reductant pressure sensor. Blocked return hose between the dosing unit and the reductant tank. Internal blockage in the dosing unit.