Diagnostic trouble code (DTC) information

Condition

Fig 1: Identifying Leak Diagnostic Pump

Courtesy of VOLVO CARS OF NORTH AMERICA.

Diagnostic trouble code (DTC) ECM-AF is stored if the control module detects that the signal from the leak diagnostic pump is too high, too low or missing.

Substitute Value

No leak diagnostic
No EVAP diagnostics.

Possible Source

Signal too high:

Short-circuit to supply voltage in the signal cable
Defective leak diagnostic pump.

Signal too low:

Short-circuit to ground in the signal cable
Short-circuit to ground in the power cable
Defective leak diagnostic pump.

Signal missing:

Open-circuit in the signal cable
Open-circuit in the power cable
Contact resistance in the terminals
Defective leak diagnostic pump.

Fault symptom[s]

Malfunction indicator lamp (MIL) lit.