P0546

4987 - P0546

Information saved in
DDE

Fault code
4987 - P0546

Fault text
DDE: Exhaust backpressure sensor before catalytic
converter, signal: Open or short circuit to positive

Fault description
Pre-oxidation catalyst temperature sensor monitoring
function. When the raw sensor signal (voltage) is greater
than the maximum limit value, the diagnostic trouble code is
logged.

Condition for fault identification
Test condition:
The error check proceeds continuously according to the
programmed process grid.
Voltage condition:
The error check proceeds continuously according to the
programmed process grid.

Condition for fault memory entry
Debounce (600 ms)

Action in service
1. Check wires and plug connections.
2. If wiring and plug connections are OK:
Exhaust-gas temperature sensor before oxidation catalyst.

Fault effect and breakdown warning
The error disables regeneration in the particulate filter.

Driver information
Warning light:
MIL

Service instruction
none