Liebherr Machine P1121 DEF Pump Out of Service Error Solution

Here is the instruction show you guide on how to solve Liebherr machine trouble code SCR system DEF pump out of service error.

 

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2026 LIEBHERR LiDIA Diagnostic Software

Liebherr Diagnostic Tool with 9 Pin Cable

 

 

Reason:

Error is active when, despite activation of the urea pump, no build-up of pressure can be detected on the DEF side of the urea pump to the SCR injector

• Urea pump does not build up any pressure in the DEF line to the injector or cannot suck from the DEF tank to the urea pump
• Maximum time is exceeded during the filling of the DEF line to the injector

 

Troubleshooting

 

 

Consequence:

As the P1121-00 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.

 

BMK

 

 

Component Location

D956-D966 A7-04 (SCR only)

D956-D966 A7-05 StageV (SCR Filter)

 

 

D9512 A7 04-05-StageV

 

Primary (A700)

 

Secondary (A760)