Key On Engine Off Self Test Procedure - Manual Revision
89Ford27ENGINE EMISSIONS DIAGNOSIS MANUALS, VOLUME H-1987 THROUGH 1989-PAGES 14-5 AND 14-11-KEY ON ENGINE OFF SELF-TEST PROCEDURE REVISED
Article No. 89-18A-10
FORD: 1987-89 CROWN VICTORIA, ESCORT 1987-88 EXP 1987-89 MUSTANG, TAURUS, TEMPO, THUNDERBIRD 1988-89 FESTIVA 1989 PROBE
LINCOLN-MERCURY: 1987-89 CONTINENTAL, COUGAR, GRAND MARQUIS
1987 LYNX 1987-89 MARK VII, SABLE, TOPAZ, TOWN CAR, TRACER
MERKUR: 1987-89 XR4TI 1988-89 SCORPIO
LIGHT TRUCK: 1987-89 AEROSTAR, BRONCO, BRONCO II, ECONOLINE, F-150, F-250, F-350, RANGER
ISSUE: The 1987, 1988, and 1989 Engine Emissions Diagnosis Manuals, Volume H, instruct the technician to turn the ignition key on, then activate self-test in order to run self-test. On some vehicles, this can result in an erroneous service code.
ACTION: Refer to the pages following this TSB article for the revised procedures.
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 680000
EEC-IV - Quick Test - All Engines 1987/1989 14-5
QUICK TEST: Key On Engine Off 3.0
Self-Test
A PERFORMING THE KEY ON ENGINE OFF SELF-TEST
SPECIAL NOTES:
^ It may be necessary to service non-EEC-IV faults before running Quick Test. Refer to Section 2.
^ Continuous Memory Codes recorded in this step will be used for diagnosis in Step 6.0 after a PASS code 11 is received in both the Key On Engine Off and the Engine Running Self-Tests.
^ Deviation from this procedure may cause the output of false codes.
^ Refer to Quick Test Appendix for further information on how to read code output.
^ On all vehicles equipped with a 2.5L or 4.9L ENGINE, the clutch must be depressed during the Key On Engine Off Self-Test.
^ On all vehicles equipped with a 7.3L DIESEL ENGINE, the throttle must be depressed (WOT) during the entire Key On Engine Off Self-Test.
HOW TO RUN THE KEY ON ENGINE OFF SELF-TEST
DO
^ Verify that the vehicle has been properly prepared according to QUICK TEST STEPS 1.0 and 2.0.
^ Activate Self-Test.
^ Place ignition key in the ON position.
^ For 7.3L Diesel vehicles only, depress the throttle.
- STAR Tester: Latch the center button in the down position.
- Analog VOM: Jumper STI to SIG RTN at the Self-Test connectors.
- "Check Engine" Light (MIL): Jumper STI to SIG RTN at the Self-Test connectors. Service Codes will be flashed on the "Check Engine" Light.
- Message Center (Continental Applications Only): Refer to Appendix: Self-Test.
^ Record all service codes displayed.
^ Go to part B of Key On Engine Off Self-Test.
DON'T
^ Depress throttle during Key On Engine Off Self-Test on gasoline engine applications.
14-6 1987/1989 EEC-IV - Quick Test - All Engines
QUICK TEST: Key On Engine Off 3.0
Self-Test
EEC-IV - Quick Test - All Engines 1987/1989 14-11
QUICK TEST: Engine Running 5.0
Self-Test
A PERFORMING THE ENGINE RUNNING SELF-TEST
SPECIAL NOTES:
^ If the engine starts but stalls, or stalls during Self-Test, Go to Pinpoint Test Step [S1].
^ On vehicles equipped with the Brake On/Off Switch (BOO), the brake pedal MUST be depressed and released AFTER the ID code.
^ On vehicles equipped with the Power Steering Pressure Switch (PSPS), within 1 to 2 seconds after the ID code, the steering wheel must be turned at least one-half turn and released.
^ On vehicles equipped with E40D transmission, the Overdrive Cancel Switch (0CS) must be cycled after the ID code.
^ The Dynamic Response code is a single pulse (or a 10 code on the STAR Tester) that occurs 6-20 seconds after the engine running identification code. (See APPENDIX: Code Output Format.)
^ When the Dynamic Response code occurs, perform a brief wide-open throttle.
HOW TO RUN THE ENGINE RUNNING SELF-TEST
DO
^ Deactivate Self-Test.
^ Start and run engine at 2,000 rpm for two minutes. This action warms up the EGO sensor.
^ Turn engine off, wait 10 seconds.
^ Activate Self Test according to Quick Test Step 3.0 A.
^ Start engine.
^ After the ID code, depress and release the brake pedal if appropriate. See Special Note above.
^ After the ID code, within 1 to 2 seconds, turn the steering wheel at least one-half turn and then release it, if appropriate. See Special Note above.
^ If a dynamic response code occurs, perform a brief wide-open throttle (WOT).
^ Record all service codes displayed.
^ Go to part B of Engine Running Self-Test.
DON'T
^ Depress the throttle unless a Dynamic Response Code is displayed.
14-12 1987/1989 EEC-IV - Quick Test - All Engines
QUICK TEST: Engine Running 5.0
Self-Test