1998 Sedan Deville has service steering system warning on dash. Fluid level is full and pump appears to be good. What is the likely source?

What year , make , model vehicle ? Warning light , electric power steering ? And what would you like to know Allison ? How to fix or what to do ? If your vehicle is a GM product , Chevy , Pontiac , Buick etc... there was a recall on a problem they had . Your best bet is to take it to a dealer .

SERVICE PROCEDURE: THE POWER STEERING FLUID REPLACEMENT PROCEDURE IS A TWO-STAGE PROCESS: FIRST, FLUSHING THE OLD FLUID FROM THE SYSTEM WITH NEW FLUID; AND SECOND, BLEEDING THE SYSTEM TO REMOVE ANY TRAPPED AIR. THE FOLLOWING TWO SEQUENCES OUTLINE THE STEPS IN EACH PROCEDURE.

FLUSHING THE POWER STEERING SYSTEM 1. RAISE THE FRONT END OF THE VEHICLE OFF THE GROUND UNTIL THE WHEELS ARE FREE TO TURN.

2. REMOVE THE FLUID RETURN LINE AT THE PUMP RESERVOIR INLET CONNECTOR.

3. PLUG THE INLET CONNECTOR PORT ON THE PUMP RESERVOIR.

4. POSITION THE FLUID RETURN LINE TOWARD A LARGE CONTAINER IN ORDER TO CATCH THE DRAINING FLUID.

5. WHILE A SECOND PERSON FILLS THE RESERVOIR WITH NEW LOW TEMPERATURE CLIMATE SERVICE FLUID, START AND RUN THE ENGINE AT IDLE.

6. TURN THE STEERING WHEEL FROM STOP TO STOP.

NOTICE: DO NOT HOLD THE WHEEL AGAINST STOPS WHILE FLUSHING THE SYSTEM. HOLDING STEERING WHEEL AGAINST WHEEL STOPS WILL CAUSE HIGH SYSTEM PRESSURE, OVERHEATING, AND DAMAGE TO THE PUMP AND/OR GEAR. 7. CONTINUE DRAINING UNTIL ALL OF THE OLD FLUID IS CLEARED FROM THE POWER STEERING SYSTEM. ADDITION OF APPROXIMATELY 1 QUART OF NEW FLUID WILL BE REQUIRED TO FLUSH SYSTEM.

8. UNPLUG PUMP RESERVOIR INLET AND RECONNECT RETURN LINE.

9. TURN ENGINE OFF, AND FILL RESERVOIR TO THE "FULL COLD" MARK.

10. CONTINUE WITH FOLLOWING PROCEDURE "BLEEDING THE POWER STEERING SYSTEM".

BLEEDING THE POWER STEERING SYSTEM AFTER REPLACING THE FLUID OR SERVICING THE POWER STEERING HYDRAULIC SYSTEM, YOU MUST BLEED AIR FROM THE SYSTEM. AIR IN THE SYSTEM PREVENTS AN ACCURATE FLUID LEVEL READING, CAUSES PUMP CAVITATION NOISE AND OVER TIME COULD DAMAGE THE PUMP. TO BLEED THE POWER STEERING SYSTEM PROCEED AS FOLLOWS:

1. BEGIN WITH THE ENGINE OFF, FRONT WHEELS OFF THE GROUND, AND WHEELS TURNED ALL THE WAY TO THE LEFT.

2. ADD LOW TEMPERATURE CLIMATE SERVICE FLUID TO THE "FULL COLD" MARK ON THE FLUID LEVEL INDICATOR.

3. BLEED THE SYSTEM BY TURNING THE WHEELS FROM SIDE TO SIDE WITHOUT HITTING STOPS.

IMPORTANT: THIS MAY REQUIRE TURNING THE WHEELS FROM SIDE TO SIDE TWENTY TIMES. ON SYSTEMS WITH LONG RETURN LINES OR FLUID COOLERS, TURNING STEERING WHEEL LOCK-TO-LOCK FORTY TIMES MAY BE REQUIRED. KEEP THE FLUID LEVEL AT THE "FULL COLD" MARK. FLUID WITH AIR IN IT HAS A LIGHT TAN APPEARANCE. THIS AIR MUST BE ELIMINATED FROM THE FLUID BEFORE NORMAL STEERING ACTION CAN BE OBTAINED. 4. START THE ENGINE. WITH THE ENGINE IDLING, RECHECK THE FLUID LEVEL. IF NECESSARY, ADD FLUID TO BRING THE LEVEL TO THE "FULL COLD" MARK.

5. RETURN THE WHEELS TO THE CENTER POSITION. LOWER FRONT WHEELS TO THE GROUND. CONTINUE RUNNING THE ENGINE FOR TWO OR THREE MINUTES.

6. TEST THE VEHICLE TO BE SURE THE STEERING FUNCTIONS NORMALLY AND IS FREE FROM NOISE.

IMPORTANT: INSPECT FOR FLUID LEAKAGE AT CONNECTION POINTS ALONG THE POWER STEERING SYSTEM. 7. RECHECK THE FLUID LEVEL AS DESCRIBED IN STEPS 3 AND 4 EXCEPT THAT THE FLUID LEVEL SHOULD NOW BE UP TO THE "FULL HOT" MARK AFTER THE SYSTEM HAS STABILIZED AT ITS NORMAL OPERATING TEMPERATURE.

FIGURES: 1 ATTACHMENT

Figure 1

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION.

Hope this may help:

Regards,
VOTIT

If you can't find a power steering fluid reservoir under the hood in the engine compartment your G6 could have Electronic Power Steering . If you look up under the dash below the steering column you will see a electric motor mounted to the steering column !
The power steering system reduces the amount of effort needed to steer the vehicle. The system uses the powertrain control module (PCM), body control module (BCM), power steering control module (PSCM), discrete battery voltage supply circuit, steering shaft torque sensor, steering wheel position sensor, power steering motor, driver information center (DIC), and the serial data circuit to perform the system functions. The PSCM and the power steering motor are serviced as an assembly and are serviced separately from the steering column assembly. The steering shaft torque sensor and the steering wheel position sensor are not serviced separately from each other or from the steering column assembly. The steering column assembly does not include the power steering motor and module assembly.

Section 11-00: Steering System-Service 1999 Taurus, Sable Workshop Manual SERVICE PROCEDURES Purging Power Steering System of Air NOTE: If the air is not purged from the power steering system correctly, a second customer concern or pump failure could result. This condition can only occur on pre-delivery vehicles with evidence of aerated fluid or vehicles that have had steering component repair.

A whine noise heard from the power steering pump may be caused by air in the system. The following procedure must be performed whenever any of the following are performed:

• All power steering noise complaints with evidence of aerated fluid on pre-delivery vehicles only, prior to any component repair.
• After any power steering system component (for example, gear or hose) has been replaced and the noise is heard.

Fluid Level Top-Off Procedure

1. Check and fill pump reservoir to dipstick full cold or remote reservoir center mark.
   

1. Disable ignition by removing Fuse 10 in the fuse junction panel.
   

1. Crank engine 30 seconds, check fluid level and add if required.
   

1. NOTE: Do not hold steering wheel on stops.
   
   Crank engine 30 seconds while cycling the steering wheel lock to lock.
   

1. Check fluid level and add fluid if required.
   

Air Purge with Vacuum External Source Procedure - 3.0L (2V) Engine, Flex Fuel and 3.4L SHO Engine

1. Tightly insert the rubber stopper of the air evacuator assembly into pump reservoir.
   

1. Reinstall Fuse 10 used to disable ignition and start vehicle.
   

1. Apply 20-25 in-Hg (85-88 kPa) maximum vacuum for minimum of three minutes at idle; maintain maximum vacuum with vacuum source.
   

1. Release vacuum and remove vacuum source.
   

1. Add fluid to full warm or reservoir center mark.
   

1. Reinstall vacuum source and apply 20-25 in-Hg (85-88 kPa) vacuum.
   

1. NOTE: Do not hold steering wheel on stops.
   
   Cycle steering wheel from lock to lock every 30 seconds for approximately 5 minutes.
   

1. Shut engine off, release vacuum and remove vacuum source.
   

1. Add Motorcraft MERCON Multi-Purpose (ATF) Transmission Fluid if necessary and install dipstick or reservoir cap.
   

1. NOTE: Do not hold steering wheel on stops.
   
   Start engine and cycle steering wheel from lock to lock every 30 seconds for approximately 5 minutes.
   

1. Check for oil leaks at all connections.
   

1. In severe cases it may be necessary to repeat air purge with vacuum source procedure.
   

Air Purge with Vacuum External Source Procedure - 3.0L (2V) and 3.0L (4V)

1. Add Motorcraft MERCON® Multi-purpose (ATF) Transmission Fluid XT-2-QDX or MERCON® equivalent to approximately 2.5 cm (1 in) (make a mark) above the top of the supply line.
   

1. Tightly insert the rubber stopper of the air evacuator assembly into the pump reservoir.
   

1. Apply 85-88 kPa (20-25 in-Hg) maximum vacuum for a minimum of three minutes.
   

1. Add Motorcraft MERCON® Multi-purpose (ATF) Transmission Fluid XT-2-QDX or MERCON® equivalent until the level is at the marked point.
   

1. Repeat Steps 3 and 4 until the fluid level stabilizes.
   

1. Check reservoir level and add Motorcraft MERCON® Multi-purpose (ATF) Transmission Fluid XT-2-QDX or MERCON® equivalent to the FULL WARM (MAX) mark.
   

1. Install the number 10 fuse in the fuse junction panel. Start the engine.
   

1. NOTE: The front wheels must be off the floor during lock-to-lock rotation of the steering wheel.
   
   NOTE: Do not hold the steering wheel on stops.
   
   Reinstall the vacuum source and apply 85-88 kPa (20-25 in-Hg) maximum vacuum and cycle the steering wheel from lock-to-lock every thirty seconds for a minimum of 5 minutes.
   

1. Shut the engine off, release the vacuum and remove the vacuum source.
   

1. Add Motorcraft MERCON® Multi-purpose (ATF) Transmission Fluid XT-2-QDX or MERCON® equivalent to the FULL WARM (MAX) level. Install the dipstick or reservoir cap.
   

1. NOTE: Do not hold the steering wheel on stops.
   
   NOTE: In severe cases, it may be necessary to repeat air purge with vacuum source procedure.
   
   Start the engine and cycle the steering wheel from lock-to-lock every thirty seconds for approximately five minutes.
   

1. Lower the vehicle front end.
   

1. Check for oil leaks at all connections.
   

bad seal/ bearing on the power steering pump or p/s gearbox. could also be a bad hose or resevoir.

Yes, your brakes are boosted by the power steering pump rather than by vacuum. I don't think it's air in the system. More likely your pump has failed, but you can try bleeding the pump. Here is a procedure from autozone.com:

Observe the following:
Use clean, new power steering fluid type only Hoses touching the frame, body or engine may cause system noise. Verify that the hoses do not touch any other part of the vehicle. Loose connections may not leak, but could allow air into the steering system. Verify that all hose connections are tight.


NOTE Power steering fluid level must be maintained throughout bleed procedure.

1. Fill pump reservoir with fluid to minimum system level, FULL COLD level, or middle of hash mark on cap stick fluid level indicator.
   NOTE With hydro-boost only, the oil level will appear falsely high if the hydro-boost accumulator is not fully charged. Do not apply the brake pedal with the engine OFF . This will discharge the hydro-boost accumulator.
   
2. If equipped with hydro-boost, fully charge the hydro-boost accumulator using the following procedure:
   1. Start the engine.
   2. Firmly apply the brake pedal 10-15 times.
   3. Turn the engine OFF
   
   
3. Raise the vehicle until the front wheels are off the ground.
4. With key in the ON position and the engine OFF , turn the steering wheel from stop to stop 12 times. Vehicles equipped with hydro-boost systems or longer length power steering hoses may require turns up to 15 to 20 stop to stops.
5. Verify power steering fluid level per operating specification.
6. Start the engine. Rotate steering wheel from left to right. Check for sign of cavitation or fluid aeration (pump noise/whining).
7. Verify the fluid level. Repeat the bleed procedure if necessary.

Observe the following:



Use clean, new power steering fluid type only Hoses touching the frame, body or engine may cause system noise. Verify that the hoses do not touch any other part of the vehicle. Loose connections may not leak, but could allow air into the steering system. Verify that all hose connections are tight.
NOTE Power steering fluid level must be maintained throughout bleed procedure.

1. Fill pump reservoir with fluid to minimum system level, FULL COLD level, or middle of hash mark on cap stick fluid level indicator.
   NOTE With hydro-boost only, the oil level will appear falsely high if the hydro-boost accumulator is not fully charged. Do not apply the brake pedal with the engine OFF . This will discharge the hydro-boost accumulator.
   
2. If equipped with hydro-boost, fully charge the hydro-boost accumulator using the following procedure:
   1. Start the engine.
   2. Firmly apply the brake pedal 10-15 times.
   3. Turn the engine OFF
   
   
3. Raise the vehicle until the front wheels are off the ground.
4. With key in the ON position and the engine OFF , turn the steering wheel from stop to stop 12 times. Vehicles equipped with hydro-boost systems or longer length power steering hoses may require turns up to 15 to 20 stop to stops.
5. Verify power steering fluid level per operating specification.
6. Start the engine. Rotate steering wheel from left to right. Check for sign of cavitation or fluid aeration (pump noise/whining).
7. Verify the fluid level. Repeat the bleed procedure if necessary.

check the fluid level on steering reservior, if ok replace your steering pump assembly

This is normal; when turned to the limits, the pump has to resort to using its pressure relieve valve, which is what you hear operating. It has to use this valve so to redirect the pressure to avoid damage of the power steering system.

Remove the accessory drive belt from the pump
Remove the pressure hose from the pump
Remove the return hose from the pump

Remove the bolts from the pump.

Remove the power steering pump from the vehicle.

Remove the power steering pump pulley from the pump

Remove the reservoir from the pump

Install the pump to the vehicle.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Install the power steering pump bolts.

Tighten
Tighten the power steering pump bolts to 34 N·m (25 lb ft).
Install the return hose to the pump.
Then just reverse what you did to remove.
Once you have it al back together fill the resevoir.
Do not over fill

Start the engine. Rotate steering wheel from left to right. Check for sign of cavitation or fluid aeration (pump noise/whining).

Verify the fluid level. Repeat the bleed procedure if necessary

BETWEEN THERESERVIOR AND PUMP ASSEMBLY THERE IS A O RING IT MAY BE MISSING OR CUT WHEN THIS PROBLEM IS CORRECTED (MAKE SURE PLASTIC RESIVOR(SP) IS NOT CRACKED) IF NO MORE LEAKS MAKE SURE IT IS FULL OF FLUID, RAISE FRONT WHEELS OFF GROUND KEY ON ENGINE OFF TURN STEERING WHEEL LOCK TO LOCK 50 TIMES. THIS FROM A CADILLAC SERVICE BULLETIN THIS WILL REMOVE AIR FROM THE SYSTEM