Electronic: Diagnosis Lincoln Continental IX

TROUBLE SHOOTING

Note. A New Generation Star (NGS) Tester (007-00500) or equivalent is required for testing the VAPS system.

Before performing individual component or system tests, check the following for possible cause of system malfunction

1. Tire Pressure
2. Mechanical Condition Of Steering
3. Power Steering Fluid Level
4. Pump Pressure
5. Faulty Fuse No. 28 In Fuse Junction Box
6. Faulty Fuse No. 4 or 11 in Power Distribution Box
7. Loose Or Corroded Connectors
8. Damaged Wiring

If problem remains after inspection, connect and operate New Generation Star (NGS) Tester (007-00500) following manufacturer's instructions. Perform data link diagnostics test. See appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT. If scan tool displays CKT 914, CKT 915 or CKT70 - NO RESPONSE/NOT EQUIPPED for vehicle dynamics module, go to TEST A .

If vehicle dynamics module passes data link diagnostics test, retrieve and record continuous Diagnostic Trouble Codes (DTCs) and perform on-demand self test vehicle dynamics module to retrieve current DTCs. See VAPS STEERING DTCS table. If no DTCs are displayed, go to SYMPTOM TESTS .

HYDRAULIC SYSTEM PRESSURE TEST

1. Reservoir must be kept full and at normal operating temperature during testing. Connect Power Steering System Analyzer (014-00207) between pressure line and pump, with gauge between pump and tester valve. Start and idle engine for 2 minutes.
2. With engine idling and fluid hot, record pressure and flow with tester valve open. If flow is less than 1.6 gals. (6.1L) per minute, pump may require service. However, proceed with testing at this point.
3. If idle pressure is greater than 150 psi (10.5 kg/cm 2 ), check hoses for restrictions. Partially close tester valve. Allow pressure to increase to 740 psi (52 kg/cm 2 ). Record flow. If flow is less than 1.7 gal/min. @ 740 psi (6.6L/min. @ 5100 kPa), replace pump.
4. Close and partially open tester valve 3 times. Tester valve must not remain closed more than 5 seconds. Observe and record pressure each time valve is closed. If readings differ more than 50 psi (3.5 kg/cm 2 ), flow control valve may be sticking. If relief pressure (valve closed) is less than 1200 psi (9520 kPa), replace power steering pump.
5. Increase engine speed to about 1500 RPM. Observe and record flow. If flow exceeds 1 gal/min. (3.78L/min.), replace power steering pump.
6. Return engine to idle speed. Turn wheel from stop to stop. Observe and record flow at both stops. Pressure should be 1200-1380 psi (8275-9520 kPa). Flow should drop to less than .5 gal. (1.9L) per minute. If pressure fails to reach maximum or if flow does not drop to less than .5 gals. (1.9L) per minute, internal leakage of steering gear exists. Replace steering gear.

VAPS STEERING DTCS

UNABLE TO ENTER SELF-TEST (1999 MODELS)

Possible source of problem may be: faulty VDM. See TEST B .

SYMPTOM TESTS

Note. To identify circuits and terminals referenced in testing, see WIRING DIAGRAMS in ELECTRONIC - CONTINENTAL article in SUSPENSION. After repairs are complete, recheck system operation to verify problem has been rectified.

TEST A: NO COMMUNICATION WITH VDM

1. Turn ignition off. Disconnect VDM 60-pin connector. Connect EEC-IV Breakout Box (014-00322). Measure resistance of Black/Light Blue wire between breakout box pin No. 60 and ground. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair Black/Light Blue wire. Clear DTCs. Repeat self-test.
2. Remove fuse No. 4 (30-amp) from battery junction box. Measure resistance between load side of fuse Dark Green/Yellow wire terminal and breakout box pin No. 57 (Dark Green/Light Green wire). If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair circuit. Clear DTCs. Repeat self-test.
3. Remove fuse No. 28 (10-amp) from central junction box. Measure resistance between load side of fuse Light Green/Violet wire terminal and breakout box pin No. 1. If resistance is less than 5 ohms, See appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT. If resistance is more than 5 ohms, repair Light Green/Violet wire. Clear DTCs. Repeat self-test.

TEST B: UNABLE TO ENTER SELF-TEST (1999 MODELS)

Connect NGS tester and attempt to communicate with VDM. If tester communicates with VDM, replace VDM. Repeat self-test. If tester does not communicate with VDM, go to TEST A .

TEST C: STEERING IS VERY DIFFICULT/VERY EASY

1. Start engine. Check for power steering pump leaks. Perform power steering pump tests. See «HYDRAULIC SYSTEM PRESSURE TEST»(ref-63570-S10941362482001021400000) . If pump is okay, go to next step. If pump fails test, replace pump. Recheck system operation.
2. Visually check steering linkage while assistant rotates steering wheel from stop to stop. If linkage moves smoothly from stop to stop, go to next step. If linkage does not move smoothly, replace damaged linkage components. Recheck system operation.
3. Check ball joints for worn surfaces. If ball joints are okay, go to next step. If ball joints are worn, replace ball joints. Recheck system operation.
4. Visually check steering gear while assistant rotates steering wheel from stop to stop. Check gear mounting for looseness. If gear is okay, and condition still exists, go to «SYMPTOM TESTS»(ref-63570-S25305871042001021400000) . If gear is loose, retighten and/or replace steering gear. Recheck system operation.

TEST D: STEERING DOES NOT VARY WITH INCREASED WHEEL ROTATION

Start engine. Check power steering pump for leaks by rotating steering wheel while observing pump. Check pump flow and pressure. See HYDRAULIC SYSTEM PRESSURE TEST . If pump leaks or does not pass system test, replace pump. Recheck system operation. If pump is okay, check hoses for damage and replace as needed. Recheck system operation.

TEST E: STEERING DOES NOT VARY WITH VEHICLE SPEED

1. Operate vehicle and check speedometer operation. If speedometer is okay, go to next step. If speedometer does not operate properly, diagnose speedometer problem in instrument cluster.
2. Turn ignition off. Connect NGS tester. Turn ignition on. Check for DTCs. If DTC U1041 is retrieved, see appropriate ANTI-LOCK article in BRAKES. If DTC U1181 is retrieved, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. If any other DTCs are retrieved, go to «VAPS STEERING DTCS»(ref-63570-S35784067022001021400000) table. If no DTCs are retrieved, replace VDM. Recheck system operation.

DIAGNOSTIC TESTS

Note. To identify circuits and terminals referenced in testing, see WIRING DIAGRAMS in ELECTRONIC - CONTINENTAL article in SUSPENSION. After repairs are complete, recheck system operation to verify problem has been rectified.