P204F

46F2 - P204F

Information saved in
DDE

Fault code
46F2 - P204F

Fault text
DDE: DeNOx system, function: Maximum duration
exceeded until metering active

Fault description
If compliance with the monitoring conditions is present =
TRUE while the metering is simultaneously still not enabled
= FALSE an error is recognized.

Condition for fault identification
Test condition:
Test conditions:
The monitoring function runs continuously when
compliance with the test conditions is present.
Voltage condition:
Test conditions:
The monitoring function runs continuously when
compliance with the test conditions is present.

Condition for fault memory entry
Debounce (1000 ms)

Action in service
1. Use diagnostic system to check temperature upstream
from SCR converter and then replace as indicated.
2. SCR metering system, check pressurization function,
replace as indicated.
3. If the fault source is a battery replacement or
undervoltage: Clear diagnostic trouble codes from ECU
error memory.

Fault effect and breakdown warning
-

Driver information
Warning light:
MIL

Service instruction
1. Plausibility check on data after 5 minutes at idle:
Temperature sensor on engine-side of SCR converter,
temperature sensor before oxidation catalyst, temperature
sensor before diesel particulate filter
2. Check pressure build-up in the SCR metering system test
module