Circuit Test D12: Notes

NOTE: This test procedures has been revised due to Ford Technical Service Bulletins, 89-18A-10.

Fig 1: IDM Circuit

NOTE: Perform this test when Service Code 14, 18, 19, 28, 45, 46, 48 or 88 is displayed during QUICK TESTS or when directed here by other test procedures.

To prevent replacement of good components, be aware that the following non-EEC related areas may be at fault:

TFI or DIS ignition module.
Ignition coil or DIS coil packs.
Spark plugs and/or high tension cables.
Distributor and PIP sensor.
Secondary ignition component arcing.

This test is intended to diagnose the following circuits and components.

Harness circuits: IGNITION GROUND, SPOUT, PIP, IDM & DPI
ECA assembly

There are 3 types of ignition system connections used with EEC-IV. They are configured as follows:

Distributorless Ignition System (DIS) - Two 6-pin connectors located at top and bottom of DIS module. Pins No. 1-6 are located on the top of the module. Pins No. 7-12 are located in the connector on the bottom of the module.
Closed Bowl Distributor (CBD) - TFI module is located on the cowl, away from the distributor. The previous mounting window in the bowl of the distributor is closed. Two connectors are used, one connecting the harness to the vehicle Hall sensor, located in the distributor, and another connecting the harness to the TFI module.

TFI Module Distributor - This is the most common system. The TFI module is mounted in the distributor and a single module connector is used.

IGNITION SYSTEM APPLICATION

Vehicle	Application
5.0L	TFI