Test Notes

You should enter this pinpoint test only when directed here from the symptom flowcharts.

This pinpoint test is intended to diagnose only the following:
- Powertrain Control Module (PCM)
- Injector Driver Module (IDM)
- Harness circuits: Electronic Feedback (EF)

Test Schematic:

DESCRIPTION
The IDM provides the EF output signal to the PCM to confirm that proper timing/duration of Fuel Delivery Command Signal (FDCS) was received. Additionally, the EF signal is used to send diagnostics of the IDM and injectors (electrical) to the PCM.

DTC DESCRIPTION
1668 = PCM-IDM diagnostic communication error.