Variable Effort Steering System: Diagnosis Oldsmobile Eighty-Eight X

DIAGNOSIS & TESTING

Note. Ensure VES power supply fuse in instrument panel fuse block is good before continuing. See WIRING DIAGRAMS . Begin VES system diagnosis with PRE-DIAGNOSTIC INSPECTION procedure.

PRE-DIAGNOSTIC INSPECTION

When checking potential VES system faults, check following before performing CIRCUIT TEST

1. Check wheel bearings for wear or damage causing wheels to wobble.
2. Check all VES system wiring harness connectors for proper engagement, loose wires or terminals and/or corrosion.

Check harness routing; pay particular attention to wheel speed sensor wiring harness routing.

1. Check for proper outer CV joint alignment and operation.
2. Check for proper tire wear (tread depth).
3. Always perform SYSTEM CHECK before diagnosing VES system.

If mechanical component malfunctions are present, or if failure is intermittent and not reproducible, test drive vehicle. Drive vehicle in a normal manner, with normal acceleration, stopping and turning.

If vehicle test drive does not reproduce any failures, perform another test drive with an ABS stop from about 30-50 MPH on surface suchas gravel. Perform sudden turns (such as evasive maneuvers). Per-form SYSTEM CHECK. If ABS warning light and/or BRAKE warning light illuminates, go to ANTI-LOCK BRAKE SYSTEM article in BRAKES.

CIRCUIT TEST

1. Perform «SYSTEM CHECK»(ref-55759-S36996956882001011700000) before proceeding. If System check has been performed, go to next step.
2. Inspect all related connectors and wiring for damage. If wiring or connectors are damaged, go to next step. If connectors and wiring are okay, go to step 4).
3. Repair connectors and wiring as necessary. After repairs, go to «SYSTEM CHECK»(ref-55759-S36996956882001011700000) .
4. Turn ignition off. Disconnect Magna Steer actuator connector. Using a DVOM, measure resistance across actuator connector (component side). If resistance is 1.6-3.1 ohms, go to next step. If resistance is not as specified, go to step 6).
5. Measure resistance between ground and either actuator connector (component side) terminal, then the other terminal. If resistance is less than infinite on both terminals, go to step 7). If resistance is not as specified, go to next step.
6. Replace actuator. After replacement, go to «SYSTEM CHECK»(ref-55759-S36996956882001011700000) .
7. Turn ignition off. Disconnect EBTCM connector. Install Pinout Box (J39700) and Cable Adapter (J39700-25) to EBTCM harness connector only. Using a DVOM, measure resistance between pinout box terminals "B" and "C". If resistance is less than infinite, go to next step. If resistance is not as specified, go to step 8).
8. Repair Gray wire circuit between actuator and EBTCM for short to ground. After repairs, go to «SYSTEM CHECK»(ref-55759-S36996956882001011700000) .
9. Using DVOM, measure resistance between pinout box terminals "B" and "F". If resistance is less than infinite, go to next step. If resistance is not as specified, go to step 11).
10. Repair White wire circuit between actuator and EBTCM for short to ground. After repairs, go to «SYSTEM CHECK»(ref-55759-S36996956882001011700000) .
11. Leave actuator harness connector connected to pinout box. Connect actuator component connector to pinout box. Using DVOM, measure resistance between pinout box terminals "C" and "F". If resistance is 1.6-3.1 ohms, go to step 17). If resistance is not as specified, go to next step.
12. If resistance in step 11) is less than 1.6 ohms, go to next step. If resistance is more than 3.1 ohms, go to step 14).
13. Repair Gray and White wire circuits between actuator and EBTCM for a short. After repairs, go to «SYSTEM CHECK»(ref-55759-S36996956882001011700000) .
14. Connect a fused jumper wire between pinout box terminals "B" and "C". Disconnect actuator component connector from pinout box. Using DVOM, measure resistance between ground and pinout box terminal "A". If resistance is less than 5 ohms, go to next step. If resistance is not as specified, go to step 16).
15. Repair open in White wire circuit between actuator and EBTCM. After repairs, go to «SYSTEM CHECK»(ref-55759-S36996956882001011700000) .
16. Repair open in Gray wire circuit between actuator and EBTCM. After repairs, go to «SYSTEM CHECK»(ref-55759-S36996956882001011700000) .
17. Turn ignition switch to RUN position. Using DVOM, measure voltage at pinout box terminal "C". If voltage is more than one volts, go to next step. If voltage is not as specified, go to step 19).
18. Repair short to voltage in Gray wire circuit between actuator and EBTCM. After repairs, go to «SYSTEM CHECK»(ref-55759-S36996956882001011700000) .
19. Using DVOM, measure voltage at pinout box terminal "F". If voltage is more than one volt, go to next step. If voltage is not as specified, go to step 21)
20. Repair short to voltage in White wire circuit between actuator and EBTCM. After repairs, go to «SYSTEM CHECK»(ref-55759-S36996956882001011700000) .
21. Replace EBTCM. After repairs, go to «SYSTEM CHECK»(ref-55759-S36996956882001011700000) .