The reductant pressure is unstable during closed loop pressure control
In order to find the reason behind this fault a number of steps can be taken. 1. Reductant delivering problem. The main cause behind this faultmode is that the system has problems to push reductant to the dosing unit. o Check that the system is not frozen. o Use the diagnostic tool to run the reductant circuit test and follow the trouble shooting instructions. The instructions will help you to check the following: - The reductant pick-up unit for leakage or clogging. - The suction hose for leakage or clogging, especially between the reductant pick-up unit and the suction hose. - The prefilter and the main filter in the reductant pump for clogging. - Overflow valve in the reductant pump opens too early. - Leakage or clogging in the pressure line between the reductant pump and the dosing unit. - Clogged prefilter in the dosing unit - Broken reductant pump
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
The reductant pressure has been outside the nominal operating range for too long during the last evaluation period while under closed loop pressure control
This fault occurs when the system has problem to deliver reductant to the dosing unit. Typical symptoms are severe drops in reductant pressure as the reductant dosing rate is increased whilst the system might still be able to function normally at lower dosing rates. Possible failures for the reductant delivering problem are: 1. Leakage or clogging in the suction hose or reductant pick-up unit, between the reductant tank and the reductant pump. 2. Clogged prefilter or main filter in the reductant pump. 3. Overflow valve in the reductant pump opens too early. 4. Leakage or clogging in the pressure line between the reductant pump and the dosing unit. 5. Clogged prefilter in the dosing unit 6. Broken reductant pump