Steering System - Variable Assist: Other Ford Thunderbird X

HYDRAULIC SYSTEM BLEEDING

1. Fill pump reservoir. Operate engine until power steering fluid reaches operating temperature. Stop engine. Recheck fluid level. Add fluid as necessary. Repeat procedure until fluid level stabilizes.
2. Raise and support vehicle so front wheels are off ground. Start engine. Turn steering wheel from side to side several times. Avoid hitting stops or holding wheel in full left or right position. Fluid level should remain visible.
3. Return wheels to center position. Operate engine for 2-3 minutes. Road test vehicle. Recheck fluid level. Fluid containing air has milky appearance. All air should be eliminated to obtain normal steering. NOTE: Abnormal noise originating from the power steering system may be caused by air trapped in system. Use Rotunda Vacuum Tester (021-00014), and follow procedure in steps 4)-8) to eliminate this condition.
4. Carefully remove pump filler adapter and dipstick. Check and fill reservoir to COLD mark. Disconnect and ground ignition coil lead. Raise and support front of vehicle.
5. Crank engine while turning steering wheel from side to side. DO NOT hold wheel on stops. Add fluid if necessary. Attach coil lead. Install vacuum tester onto reservoir. NOTE: DO NOT use engine as vacuum source to purge air from power steering system.
6. Start engine. Apply 15 in. Hg vacuum to reservoir for approximately 3 minutes with engine idling. As air is purged from system, vacuum will decrease.
7. Maintain sufficient vacuum with vacuum source. Release vacuum. Check fluid level. Install filler adapter assembly and dipstick. Start engine.
8. Turn steering wheel from side to side while checking for leaks. If condition is severe, repeat procedure until all air is removed. Lower vehicle. Road test vehicle.

POWER STEERING PUMP BELT

Belt tension is adjusted automatically. Automatic belt tensioner has belt wear indicator marks located on top of tensioner housing. If tension indicator mark is not between wear indicator marks, belt is worn or incorrect belt is installed. Replace belt, if necessary.

RACK YOKE PLUG CLEARANCE

Note. This is not a routine service adjustment. It is only required when input shaft and valve assembly are removed. Steering gear unit must be removed from vehicle.

1. Clean exterior of steering gear. Install 2 long bolts and washers through bushings, and attach unit to Bench Mounted Holding Fixture (T57L-500-B).
2. DO NOT remove external pressure lines unless necessary. If lines are removed, they must be replaced. Drain fluid by rotating pinion shaft lock to lock twice using Pinion Shaft Torque Adjuster (T74P-3504-R). Cover ports on valve housing with a cloth while draining gear.
3. Insert an INCH-pound torque wrench in pinion shaft torque adjuster. Position adapter and wrench on pinion shaft splines. Rotate pinion shaft in both directions. Record rotation torque required. If rotation torque is not within specification, adjust pinion preload.
4. To adjust pinion preload, loosen yoke plug lock nut using Pinion Housing Yoke Lock Nut Wrench (T78P-3504-H). (Scheme 28) Loosen yoke plug with a 3/4" socket.
5. Clean yoke plug threads. With rack centered, tighten yoke plug to 45-50 INCH lbs. (4.5-5.7 N.m). Loosen yoke plug approximately 1/8 turn, until torque is to specification. See «PINION SHAFT ROTATION TORQUE TABLE»(ref-54923-S10155463622001011700000).
6. Position Pinion Housing Yoke Lock Nut Wrench (T78P-3504-H) on yoke plug lock nut. Hold yoke plug and tighten lock nut to 44-66 ft. lbs. (60-90 N.m). Ensure yoke plug does not move or preload will be incorrect. After tightening lock nut, recheck pinion shaft rotation torque.

PINION SHAFT ROTATION TORQUE

Scheme 28

POWER STEERING PUMP

Note. On supercharged engines, intercooler and intercooler tubes must be removed to gain access to power steering pump.

POWER STEERING PUMP PULLEY

Note. Pump must be removed from vehicle before pulley can be removed or installed.

For connector side

1. 16-gauge wire, 18" (457 mm) long.
2. Connector (E9SB-14489-EA).
3. 2 terminals (E8VB-14474-BA).

For light side

1. Light socket (E2DB-13728-A).
2. 2 terminals (D4AB-14490-D, E or F).
3. No. 194 or No. 161 bulb.

An analog volt-ohmmeter and a digital volt-ohmmeter are also required for testing.

QUICK TESTS

Note. In the following diagnostic tests, circuit diagrams and illustrations are provided Courtesy of Ford Motor Co.

Check Connections

Verify EVO actuator valve (on power steering pump) and EVO control module harness connectors (in trunk) are firmly seated. If connectors are NOT firmly seated, make proper connection and proceed to QUICK TEST A2 . If connectors are seated properly, proceed to QUICK TEST A2 .

Control Module Check

1. Turn ignition off. Locate service diagnostic connector in upper glove box. Connect fabricated EVO system diagnostic light to service connector. See «EVO TESTING PROCEDURE»(ref-54923-S19145199352001011700000) under TESTING for diagnostic light fabrication. (Scheme 29) Start engine.
2. When engine starts, control module should illuminate the diagnostic light for one second. This indicates control module and bulb are functional.
3. If light illuminates for one second, proceed to «QUICK TEST A3»(ref-54923-S07372561112001011700000). If light does NOT illuminate for one second, proceed to «QUICK TEST E1»(ref-54923-S42291125672001011700000). If light flickers, proceed to «QUICK TEST E1»(ref-54923-S42291125672001011700000).

Fabricating EVO System Diagnostic Light. Scheme 29

Actuator Output Circuit Check

1. If a short to ground or an open exists in circuit, after a 2-second delay, the diagnostic light will flash a Code 6. A Code 6 is indicated by light turning ON for 1/2 second and OFF for 1/2 second, 6 times. After a 2-second delay, the code will repeat until power is turned off.
2. If light flashes a Code 6, delays 2 seconds and repeats Code 6, proceed to «QUICK TEST B1»(ref-54923-S00781236822001011700000) .
3. If light does NOT illuminate after 2-second delay, proceed to «QUICK TEST A4»(ref-54923-S18808884032001011700000) . Actuator output circuit is okay.

Steering Wheel Sensor Check

Start engine and let idle. Rotate steering wheel from lock to lock. If diagnostic light illuminates for 3 seconds, proceed to QUICK TEST A5 . If diagnostic light does NOT illuminate, proceed to QUICK TEST C1 .

Vehicle Speed Sensor Check

Raise back wheels off ground on jackstands. Start vehicle. Hold steering wheel straight. Increase speed to greater than 15 MPH. If light illuminates at speed greater than 15 MPH, proceed to QUICK TEST A6 . If light does not illuminate at speed greater than 15 MPH, proceed to QUICK TEST D1 .

Raise back wheels off ground on jackstands. Start vehicle. Hold steering wheel straight. Increase speed to less than 10 MPH. If diagnostic light turns off at speed less than 10 MPH, speed sensor electrical circuit is working properly. Proceed to QUICK TEST A7 . If light does NOT turn off at speed less than 10 MPH, proceed to QUICK TEST D1 .

Service Power Steering

Check power steering pump pressure and flow. See POWER STEERING PUMP FLOW TEST SPECIFICATIONS TABLE under TESTING. Replace as required. Testing requires Power Steering System Analyzer (014-00207).

Code 6 Activated During Actuator Check

Turn ignition off. Verify EVO actuator valve harness connector is firmly seated. If connector is NOT firmly seated, make proper connection and proceed to QUICK TEST A2 . If connector is firmly seated, proceed to QUICK TEST B2 .

Actuator Valve Resistance

Turn ignition off. Locate control module in module package tray, in trunk. Measure resistance between pins No. 13 and pin 14 of EVO control module 14-pin connector. (Scheme 30) If resistance is less than 18 ohms, proceed to QUICK TEST B3. If resistance is 18-1000 ohms, proceed to QUICK TEST B4.

Identifying EVO Control Module Connector Pins. Scheme 30

EVO Actuator Valve Resistance

Disconnect EVO actuator valve harness connector at pump. Measure resistance between 2 actuator valve connector pins. If resistance is 5-20 ohms, proceed to QUICK TEST B5 . If resistance is NOT within specification, replace EVO actuator valve.

Short Circuit Check

Turn ignition off. Leave EVO actuator valve harness disconnected. Disconnect 14-pin connector from EVO control module. For component location, see EVO CONTROL MODULE under REMOVAL & INSTALLATION. Proceed to QUICK TEST B6 .

Check resistance between pins No. 5 (Black wire) and 13 (Yellow/Light Green wire) of the EVO harness connector. If resistance is greater than 1000 ohms, proceed to QUICK TEST B7 . If resistance is less than 10 ohms, service wiring harness and proceed to QUICK TEST B7. If resistance is 10-1000 ohms, proceed to QUICK TEST B8 .

Measure resistance between pin No. 5 (ground) and pin No. 14 (Light Blue wire) of EVO harness connector. If resistance is less than 10 ohms, service EVO harness and proceed to QUICK TEST B8 . If resistance is greater than 10 ohms, proceed to QUICK TEST B8 .

Short Circuit Check Between Circuits No. 330 & 353

Turn ignition off. Disconnect EVO actuator valve harness at power steering pump. Disconnect EVO control module 14-pin harness connector. Measure resistance across pin No. 13 (Yellow/Light Green wire) and pin No. 14 (Light Blue wire) of EVO control module connector. see scheme 15 If resistance is less than 10 ohms, a short circuit is indicated. Service wires and proceed to QUICK TEST A1. If resistance is more than 1000 ohms, replace EVO control module.

Steering Wheel Rotation Sensor Connector Check

Verify steering wheel rotation sensor connector, at base of steering column, is properly seated. If connector is properly seated, proceed to QUICK TEST C2 . If connector is NOT properly seated, make proper connection and proceed to QUICK TEST A1 .

Steering Wheel Rotation Sensor Check

1. Turn ignition off. Disconnect EVO control module 14-pin harness connector. Examine wiring harness for damage. Ensure the following wires correspond to the following pin numbers. (Scheme 30)for terminal identification. Red wire (circuit No. 633) in pin No. 1. Brown wire (circuit No. 634) in pin No. 6. Yellow/Black wire (circuit No. 837) in pin No. 12.
2. If damaged or crossed wires are found, service wires and proceed to «QUICK TEST A1»(ref-54923-S36392699712001011700000). If wires are okay, proceed to «QUICK TEST C3»(ref-54923-S16963527582001011700000).

Steering Wheel Rotation Sensor Signal Check

1. Use a jumper wire to connect pin No. 12 (Yellow/Black wire) and pin No. 5 (Black wire) of the 14-pin EVO harness connector. Start engine. Set analog ohmmeter to 1000 ohm scale. While rotating steering wheel slowly, measure resistance between pin No. 1 (Red wire) and pin No. 5 (Black wire). Measure resistance between pin No. 6 (Brown wire) and pin No. 5. NOTE: The resistance values will vary between meters. The needle on all meters should swing from a lower to higher resistance and back, approximately every 9 degrees of steering wheel rotation.
2. If meter needle swings for both circuits, the steering wheel rotation sensor is functional. Replace EVO control module and re-test system. If meter does NOT swing for both circuits, disconnect jumper wire and proceed to «QUICK TEST C4»(ref-54923-S26449985632001011700000) .

Steering Wheel Rotation Sensor Wire Check

Turn ignition off. Disconnect steering wheel rotation sensor connector at lower steering column. Inspect sensor wires for damage. Test continuity of Red wire (circuit No. 633), Brown wire (circuit No. 634) and Yellow/Black wire (circuit No. 837) between steering sensor and EVO control module harness. If wires are damaged or crossed, service wires as necessary. If no continuity exists, service wires as necessary and proceed to QUICK TEST A1 . If no problems are found, proceed to QUICK TEST C5 .

Short Across Circuits No. 834 & No. 835 Check

1. Turn ignition off. Disconnect steering wheel rotation sensor. Disconnect EVO control module 14-pin connector. (Scheme 30) Measure resistance between following pins in EVO harness: Pin No. 1 and pin No. 6. Pin No. 1 and pin No. 12. Pin No. 6 and pin No. 12.
2. If resistance is more than 1000 ohms, proceed to «QUICK TEST C6»(ref-54923-S00080902882001011700000). If resistance is less than 10 ohms, service wires as necessary and proceed to «QUICK TEST A1»(ref-54923-S36392699712001011700000).

Vehicle Speed Sensor Connector Check

Verify vehicle speed sensor connector is properly seated. If connector is properly seated, proceed to QUICK TEST D2 . If connector is NOT properly seated, make proper connection and proceed to QUICK TEST A1 .

Speed Sensor Check

1. Turn ignition off. Disconnect EVO control module 14-pin harness connector. Examine wiring harness for damage. Verify the following wires correspond to these pin numbers: Dark Green/White wire (circuit No. 150) in pin No. 9. Gray/Red wire (circuit No. 359) in pin No. 8.
2. If damaged or crossed wires are found, service wires and proceed to «QUICK TEST A1»(ref-54923-S36392699712001011700000) . If wires are okay, proceed to «QUICK TEST D3»(ref-54923-S02100249152001011700000) .

Control Module Retest

Turn ignition off. Connect EVO system diagnostic light to connector in upper glove box. (Scheme 29) Start engine. If light illuminates for one second, proceed to QUICK TEST A3. If light does NOT illuminate, proceed to QUICK TEST F1. If light flickers, replace EVO control module.

EVO Control Module Check

Turn ignition off. Ensure 14-pin connector is properly connected to EVO module. If connection is okay, proceed to QUICK TEST F2 . If connection is NOT okay, secure connection and proceed to QUICK TEST A2 .

Control Module Power Feed Check

1. Turn ignition off. Disconnect EVO control module 14-pin connector. (Scheme 29) Turn ignition to RUN position. Using a digital volt-ohmmeter, measure voltage from pin No. 7 (Purple/Orange wire) and pin No. 5 (ground, Black wire) at 14-pin connector.
2. If 12 volts are present, replace EVO control module. If no voltage is present, repair short to ground or open in Purple/Orange wire (circuit No. 298). Return to «QUICK TEST A1»(ref-54923-S36392699712001011700000).