P20B8

45F1 - P20B8

Information saved in
DDE

Fault code
45F1 - P20B8

Fault text
45F1: Reducing agent, output of feed module heater power
too high: Short circuit, heater circuit

Fault description
Starting with 03/2010 the heating units for the delivery
module and the metering line are activated consecutively
with a 500 ms delay. This results in two peaks in the lead
value. The error is recognized when the first spike in the
lead value is above the limit 0 1/Ohm.

Condition for fault identification
Test condition:
A check for this error runs once per heating cycle.
Voltage condition:
A check for this error runs once per heating cycle.

Condition for fault memory entry
Event debounced (1)

Action in service
- If the DTC 4603 also appears at the same time: Replace
power switch.
. Repair sources of electrical tracking and arcing (moisture
in the wiring or plug connections).
- Check resistance of the delivery module's heating system.
- Replace power switch.

Fault effect and breakdown warning
-

Driver information
Warning light:
MIL

Service instruction
If the new version of the power switch is installed measure
the resistance of the delivery module heating system's
circuits.
Delivery module heater resistance:
2.9 - 5.5 ohms