Diagnostic Trouble Code Memory (Section 11): Notes

NOTE: For aid in using diagnostic charts, see USING DIAGNOSTIC CHARTS .

The engine control module (N3/4) for the HFM-SFI system is equipped with diagnostic trouble code (DTC) memory. Malfunctions are recognized and stored as trouble codes and are distinguished as:

Malfunctions which are constantly present.
Malfunctions which occur longer than 3 seconds.
Intermittent contact malfunctions which have occurred 5 times during a trip.

The DTC memory remains active even if the vehicle's battery is disconnected. Malfunctions which are no longer present, are automatically erased again after a maximum of 19 trips. A trip has occurred if:

Vehicle Speed > 2.5 MPH (4 m/h)
Engine Speed > 700 RPM
Engine Shut Off For 30 Seconds

The stored diagnostic trouble codes (DTC) can be read at the data link connector (DTC readout - X14/4) with the ignition switched ON or with the engine running. Diagnosis via an On-Off Ratio readout has been eliminated.