"Check Engine", "Check DCL", Or "Service Engine Soon" Light/Message

NOTE: You should perform this test only when Code 70, 71 or 72 is displayed, or when directed here by other test procedure or driveability symptom.

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

Fuse, bulb, or socket
NOTE: This test is intended to diagnose only the following:
ECA
Data Communications Link (DCL)

Fig 1: "CHECK ENGINE" Indicator Ckt

DATA COMMUNICATIONS LINK WIRE COLOR IDENTIFICATION

Application (Test Pin No.)		Wire Color
Pin 17, STO/MIL
2.3L PFI		Tan
4.9L, 5.0L, 5.8L, 7.5L (Bronco & F-Series) & 7.3L Diesel (F-Series)		Pink/Light Green
All Others		Tan/Red

Fig 2: Data Communication Link (DCL) Circuit (If Equipped)

TEST PIN WIRE COLOR IDENTIFICATION