Air pump switchover valve, ME-SFI fault code description
Air pump switchover valve
1
Fault code
( Display on generic scan tool)
P2024 (P0412)
2
Fault storage
Activation of the engine diagnosis indicator lamp (EURO3/4)
or CHECK ENGINE (MIL) malfunction indicator lamp
After expiry of test duration and fault
Following two successive driving cycles with faults
3
Checking frequency
Continuous
4
Checked signal or status
Current/ voltage test at air pump switchover valve
5
Fault setting conditions
Limit values
Short circuit to ground
Short-circuit to +12 V
Line interruption
Voltage lower than 2.5 V
Current higher than 4.2 A
No voltage at air pump switchover valve
Approx. 4 to 8 V at output of ME-SFI control unit under no load.
6
Check prerequisites
Battery voltage between 8 and 17 V
7
Actuation of each air pump switchover valve is checked for detection of a line interruption or short-circuit (to ground or battery voltage). A short circuit to ground and a line interruption will be detected when the output stages are locked, whilst a short circuit to the battery voltage will be detected when the output stages are conducting.
The output stage is immediately no longer activated when a fault arises.