Manufacturer Code Charts: 2789

2789 - P0420

Information saved in
DME

Fault code
2789 - P0420

Fault text
Conversion rate of Bank 1 catalytic converter

Fault description


Condition for fault identification
Test condition:
Oxygen load - Forced stimulation with pulse stroke is
active: * Engine temperature > K_O2_OBD_TMOT)*
Engine rpm within range (K_O2_OBD_N_Max
u.K_O2_OBD_N_Min)
* Relative induction charge density within range
(K_O2_OBD_Rf_Max u.K_O2_OBD_RF_Min) * Catalytic
converter temperature within range
Terminal condition: Engine running -
idle or partial load
Voltage condition:
none

Condition for fault memory entry
Diagnosis value above the threshold
K_Kat_OBD_WERT_Max

Action in service
1. Check exhaust system for leaks /2. No faults related to
oxygen sensor or fuel system or VANOS should be present
/3. Conduct oxygen sensor test routines, even if no oxygen
sensor fault is present./ 4. Replace catalytic conventer near
engine

Fault effect and breakdown warning
MIL on after engine runs 2x

Driver information
Warning light:
No

Service instruction
none