Service steering system 98 deville

Doesn't use power steering fluid ,your vehicle has electrric power steering . What's the problem ? Light or message on instrument cluster ? SERVICE POWER STEERING
The electric power steering (EPS) system reduces the amount of effort needed to steer the vehicle. The system uses the body control module (BCM), power steering control module (PSCM), torque sensor, discrete battery voltage supply circuit, EPS motor, serial data bus, and the instrument panel cluster (IPC) message center to perform the system functions. The PSCM, torque sensor, nor the EPS motor are serviced separately from each other or from the steering column. Ant EPS components diagnosed to be malfunctioning requires replacement of the steering column assembly, also known as the EPS assembly.
Your best bet ,take it to a qualified repair shop.

eps ???? spell it out electric power steering (EPS) system ? The system uses the body control module (BCM), power steering control module (PSCM), torque sensor, discrete battery voltage supply circuit, EPS motor, serial data bus, and the instrument panel cluster (IPC) message center to perform the system functions. The PSCM, torque sensor, nor the EPS motor are serviced separately from each other or from the steering column. Ant EPS components diagnosed to be malfunctioning requires replacement of the steering column assembly, also known as the EPS assembly.
The scan tool won't communicate with what ? The power steering control module , BCM or PCM/ECM .

SERVICE STEERING SYS
Refer to Variable Effort Steering System Description and Operation in Variable Effort Steering

Your best bet , take it to the dealer .
Variable Effort Steering System Description and Operation
The Variable Effort Steering (VES) System varies the amount of effort to steer the vehicle as wheel speed changes or lateral acceleration occurs. The Electronic Brake Control Module (EBCM) controls an actuator located in the steering rack and pinion. The actuator consists of an electromagnetic coil and a pintle valve which moves in and out of the rack and pinion's input fluid orifice, regulating power steering fluid flow. The EBCM commands current from 0-1 amp to the VES actuator which varies the amount of effort to steer the vehicle. At low speeds, 1 amp of current is commanded to the VES actuator and the pintle valve is fully retracted which provides maximum fluid flow and maximum steering assist for easy turning and parking maneuvers. At high speeds, no current is commanded and the pintle valve moves closer to the orifice, decreasing fluid flow, providing firmer steering (road feel) and directional stability. The VES system uses the steering wheel position sensor input to calculate lateral acceleration during abrupt driving maneuvers. The system also uses the Antilock Brake System (ABS) wheel speed sensor inputs to determine vehicle speed. The EBCM is constantly monitoring these inputs to achieve the desired current to the VES actuator. The EBCM has the ability to detect malfunctions in the VES actuator or the circuits to the actuator. Any malfunctions detected will cause the VES outputs to be disabled and the EBCM will command the Driver Information Center (DIC) to display the SERVICE STEERING SYSTEM warning message via a class 2 serial data circuit.
Step
Action
Yes
No
Schematic Reference: Steering Assist Schematics
1
Install a scan tool.
Does the scan tool turn ON?
Go to Step 2
Go to Scan Tool Does Not Power Up in Data Link Communications
2
Turn ON the ignition, with the engine OFF.
Attempt to establish communication with the EBCM.
Does the scan tool communicate with the EBCM?
Go to Step 3
Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications
3
Select the ABS Diagnostic Trouble Codes function on the scan tool.
Does the scan tool display any DRP/ABS/TCS or VSES DTCs?
Go to Diagnostic System Check - ABS in Antilock Brake System
Go to Step 4
4
Does the scan tool display any DTCs which begin with a "U"?
Go to Diagnostic Trouble Code (DTC) List in Data Link Communications
Go to Step 5
5
Does the scan tool display "DTC C0450?"
Go to Diagnostic Trouble Code (DTC) List
System OK

Wrench light means you have a fault or service is due. Not sure what fault is . If it is a fuse the part cost is small, not sure about labour cost, it depends on where fuse is located but shouldn't take more than a few minutes. Hope this helps

SERVICE ELECTRICAL SYS - 106
The IPC illuminates the SERVICE ELECTRICAL SYS -- 106 message in the DIC when one of the following conditions exist:
?€¢
The dash integration module (DIM) detects a malfunction that is related to the ignition switch.

The IPC receives a class 2 message requesting illumination from the DIM.

?€¢
There is a powertrain related code present.

The IPC receives a class 2 message requesting illumination from the PCM. Dash Integration Module (DIM)
The various DIM input and output circuits are described in the corresponding functional areas as indicated on the DIM electrical schematics.
The DIM functions include the following:
?€¢
Class 2 communication requiring DIM interaction.

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Control of exterior lamps.

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Control of front fog lights.

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Control of the headlights.

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Headlamps on with wiper input.

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Hood ajar switch input w/export.

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Horn relay control.

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Interior lamps incandescent dimming.

?€¢
Low side temperature for HVAC compressor.

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Power moding control over Class 2 serial data circuit.

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Reverse lockout solenoid control.

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Steering wheel controls input.

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Storage of the clock settings and, sending a message out on the class 2 serial data circuit in response to requests from other modules.

On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the DIM. The PMM receives 4 signals from the ignition switch.
To determine the correct power mode the PMM uses the following circuits:
?€¢
Accessory voltage

?€¢
Ignition 1 voltage

?€¢
Ignition 3 voltage

?€¢
Off/Run/Crank voltage

Your having a module problem , need to have it checked for DTC'S . Dealer only one for that !

On most models, you turn the key switch on but don't start the engine. Push "off" and "warm" to enter the diagnostics program.
When 70 appears on the fuel screen, push "off" and "high fan" at the same time and hold until all symbols and numbers appear, then release.

Sounds like the bearing on the pulley that runs the Power Steering pump is shot. Have it serviced.

You can't get the codes if they were erased prior.

PWR STR message
Power Steering: Refer to Power Steering System Description and Operation in Power Steering System

The electric power steering (EPS) system reduces the amount of effort needed to steer the vehicle. The system uses the body control module (BCM), power steering control module (PSCM), torque sensor, discrete battery voltage supply circuit, EPS motor, serial data bus, and the instrument panel cluster (IPC) message center to perform the system functions. The PSCM, torque sensor, not the EPS motor are serviced separately from each other or from the steering column. Any EPS components diagnosed to be malfunctioning requires replacement of the steering column assembly, also known as the EPS assembly.

Having a qualified repair shop check it out would be your best bet ! Do you know what DTC'S are ? diagnostic trouble codes

DTC C0000
DTC C0475
DTC C0476
DTC C0545
DTC C0847
DTC C0848
DTC C0896
DTC C0899
DTC C0900

Chevy Cobalt Trac Light On Harsh Shifting and NO COM All Modules
Your saturn is the same as the cobalt . You have a computer problem or serial data network .

This is most likely referring to the steering positioning sensor but to know for sure you will have to have a code reader to get the code and go from there. Sorry, but whiteout a code there is no way to tell you any more.