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Home >> Ford >> 1990 >> Bronco II 4WD, Standard, M5OD-R1 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Test N - Ignition/Erratic Diagnostic Monitor (IDM) >> Test N - Introduction
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Test N - Introduction

NOTE: Perform this test when Code 14, 18, 19, 28, 45, 46, 48 or 88 is displayed during QUICK TEST or when directed here by other test procedure or driveability symptom. This test is intended to diagnose only the EEC-IV portion of the ignition system. For additional information on ignition system and component testing, see SYSTEM/COMPONENT TESTS article.
NOTE: To prevent replacement of good components, be aware that the following non-EEC related areas may be at fault:
TFI IGNITION MODULE LOCATION

Application Location
7.5L PFI (Truck) Distributor
Fig 1: 7.5L PFI IDM Circuit
G90F13289
Fig 2: 2.3L OHC PFI Truck (EDIS) IDM Circuit
G90A13292
Fig 3: 4.0L MA PFI Truck (EDIS) IDM Circuit
G90C13294
TEST PIN WIRE COLOR IDENTIFICATION

Application (Test Pin No.) Wire Color
Pin 4, IDM
5.0L MA (Town Car) White/Light Blue
Bronco & F-Series Tan/Yellow
All Others Dark Green/Yellow
Pin 16, IGN GND
2.3L, 2.9L (Truck) Black
7.5L PFI Black/Orange
All Others Black/Orange
Pin 36, SPOUT/SAW
Bronco & F-Series Pink
All Others Yellow/Light Green
Pin 56, PIP
4.0L (Aerostar) Dark Blue
4.0L (Bronco II & Ranger) Black/Light Blue
7.5L Bronco & F-Series Gray/Orange
Bronco & F-Series Gray/Yellow
All Others Dark Blue

There are 4 types of ignition system connections used with EEC-IV. They are configured as follows: