Self Test Output (STO) Access At DLC - Inoperative
Article No.94-9-5
05/04/94
^ SELF TEST OUTPUT (STO) CAN BE ACCESSED ONLY THROUGH MALFUNCTION INDICATOR LAMP (MIL) - 1.8L 4EAT APPLICATIONS ONLY - VEHICLES BUILT FROM 11/1/93 THROUGH 3/15/94
^ SELF TEST OUTPUT (STO) CIRCUIT AT DATA LINK CONNECTOR (DLC) INOPERATIVE - 1.8L 4EAT APPLICATIONS ONLY - VEHICLES BUILT FROM 11/1/93 THROUGH 3/15/94
FORD:
1994 ESCORT
LINCOLN-MERCURY:
1994 TRACER
ISSUE:
Wiring harnesses installed in some vehicles may not activate Self-Test Output (STO) through the Data Link Connector (DLC). STO may be accessed through the Malfunction Indicator Lamp (MIL) only.
ACTION:
Splice the STO circuit to the MIL circuit. This will activate the Data Link Connector. Refer to the following procedure for service details.
The affected vehicles will display Diagnostic Trouble Codes (DTC's) through the MIL as usual. However, DTC's cannot be retrieved through the STO terminal at the DLC. If use of the New Generation Star (NGS), Super Star II or a voltmeter is preferred, the following wire harness update should be performed.
1. Disconnect the battery ground cable.
2. Remove parking brake console, shift console and control box side cover. Refer to the 1994 Escort/Tracer Service Manual, pages 01-12-5 and 01-12-6.
3. Disconnect 22-pin Powertrain Control Module (PCM) connector. Remove six (6) inches (152.4 mm) of winding tape from the PCM branch of the main wiring harness to facilitate access to the wires, Figure 1.
4. Locate the White/Black wire at pin 1F and the Yellow/Black wire at pin 1E. Refer to the 1994 Powertrain Control/Emissions Diagnosis (PC/ED) Manual, page 3B-20.
5. Cut the W/BK wire approximately three (3) inches (76.2 mm) from the connector.
6. Connect the W/BK wire (harness side) to the Y/BK wire using a splice lock connector (Scotchlock, or equivalent).
7. Remove the remaining W/BK wire and terminal from the connector and discard, Figure 2.
8. Re-tape harness branch using new electrical tape.
9. Reconnect 22-pin connector to the PCM.
10. Reinstall control box side cover, shift console and parking brake console. Refer to the 1994 Escort/Tracer Service Manual, pages 01-12-5 and 01-12-6.
11. Reconnect battery ground cable.
12. With engine running, measure voltage between STO terminal at the DLC and chassis ground. Voltage should be 12-14 volts.
PART NUMBER PART NAME CLASS
(Obtain Locally) Splice Lock Connector A
(Scotchlock Or Equivalent)
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS:
Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage
OPERATION DESCRIPTION TIME
940905A Cut And Splice Wires 0.4 Hr.
DEALER CODING
BASIC PART NO. CONDITION CODE
14401 28
OASIS CODES: 203000