This instruction show you guide on how to solve Liebherr machine engine D966 D9512 ECU2 ECU2-HD ECU3 trouble code P1120 scr system (air pump/air supply valve) out of service.
Related Contents:
Liebherr LIDIA 2026 Diagnostic Software
Reason:
The failure code is displayed during check phase :
- Air supply is always ON (No air supply stop in Sensor Check phase)
- Air supply is always OFF (No air supply in PreCheck 1/2/3 phase)
Troubleshooting
Consequence:
- As the P1120-00 failure is emission relevant, the inducement process starting with P1187-00 “Inducement system – Warning (SCR failure) will begin, leading to a power reduction if the failure is not solved.
- If a second occurrence of the failure comes back, this leads to a repeated offense issue which means that the engine will stay blocked in the latest stage of inducement. As a consequence, Service Technician is needed to remove the power reduction.
Component Location:
EATS All versions
D956-D966 A7-04 (SCR only)
D956-D966 A7-05 StageV (SCR Filter)
D9512 A7 04-05-StageV
Primary (A700)
Secondary (A760)
