1990-1996 Infiniti Q45 Power Steering Module: Solving Heavy Steering and Compatibility Issues
Your definitive guide to diagnosing, replacing, and buying a used power steering control module for the first-generation Infiniti Q45, including critical suspension-related differences.
- Compatibility is critical: This module (28500-60U10) is ONLY for Q45s WITHOUT the optional Full-Active Suspension (FAS).
- No programming is required for this module; it is a direct plug-and-play replacement.
- The most common failure symptoms are heavy steering or inconsistent power assist that is not accompanied by pump noise.
- Due to the part's age, internal capacitor failure is a high probability. Consider buying a rebuilt unit or having a used one serviced.
Symptoms of a Failing Power Steering Control Module
When the power steering control module begins to fail, it can cause confusing symptoms that might be mistaken for a bad power steering pump or steering rack. Owners typically report one or more of the following issues:
- Heavy or Stiff Steering: The most common symptom is steering that feels extremely heavy, as if there is no power assist at all. This can happen intermittently or become a permanent condition.
- Inconsistent Steering Assist: The steering effort may change unexpectedly while driving. It might feel normal one moment and then become very heavy, or vice-versa. Some owners report the assist cutting in and out while turning the wheel.
- No Change in Assist with Speed: You may notice that the steering feels too light and over-boosted at highway speeds, or too heavy at parking lot speeds. This indicates the speed-sensitive function has failed.
- Warning Lights: A failure in the system can trigger a power steering warning light on the dashboard, if equipped.
It's important to also check other components before condemning the module. A failing power steering pump will often make a whining noise, and a binding steering U-joint can also cause stiff or notchy steering.
Warning: Before replacing any parts, check the power steering fluid level and condition. Also, inspect the steering rack U-joint for binding, as this is another common cause of stiff steering on these cars.
Vehicle Compatibility: The Active Suspension Question
This is the most critical information to understand before buying a replacement module. The correct part depends on which suspension your Q45 has.
- Standard Suspension: Most 1990-1996 Q45 models came with a standard suspension. These vehicles use the power steering control module with OEM part number 28500-60U10.
- Full-Active Suspension (FAS): From 1991 to 1995, Infiniti offered an extremely advanced and complex hydraulic "Full-Active Suspension" as an option. Cars with this system were designated as the "Q45A". This system has its own, separate control modules and does NOT use the standard power steering control module. The initial information about "High Capacity Active Control Suspension" appears to be a misnomer for the FAS system.
For 1990-1994 models, the module 28500-60U10 fits vehicles WITHOUT Full-Active Suspension. For 1995-1996, this module fits all vehicles, as the Q45A with FAS was discontinued after the 1995 model year.
Buying a Used Power Steering Control Module
Since new OEM modules have been discontinued, buying a used part is the most common solution. Here’s what to look for:
- Verify the Part Number: Absolutely confirm the part number on the unit is 28500-60U10. Do not rely on a seller's description alone.
- Inspect the Connectors: Check for any signs of corrosion, bent pins, or heat damage on the electrical connectors.
- Look for Water Damage: The module is located inside the cabin, but leaks can happen. Look for any signs of water stains or corrosion on the module's case.
- Ask About Capacitor Health: For an electronic part this old, failure of the internal capacitors is a very common issue. Some sellers offer modules that have been preemptively rebuilt with new capacitors. If you are buying a standard used module, be aware that you may need to have it repaired in the future.
Pro Tip: Given the age of these modules, even a good used one can fail due to aging capacitors. Consider buying from a seller who specializes in rebuilding these units, or factor in the cost of having the capacitors replaced by an electronics repair shop as a preventative measure.
Diagnosis and Replacement
Location
The power steering control module is located in the center of the dashboard, behind the radio and climate control unit, typically to the driver's side of the radio. Accessing it requires removing the center console trim and the radio/climate control assembly.
Programming and Installation
The power steering control module for the 1990-1996 Q45 is a simple, plug-and-play unit. No programming, flashing, or dealer visit is required after installation. Simply disconnect the battery, swap the module, and reconnect everything.
Known Issues, TSBs, and Recalls
There are no specific recalls or Technical Service Bulletins (TSBs) from Infiniti or the NHTSA that directly address the power steering control module for the 1990-1996 Q45. Recalls found for Infiniti steering systems apply to much newer models with different technologies.
Cost Comparison
Pricing can vary, but here is a general breakdown of what to expect:
| Part Type | Estimated Cost | Notes |
|---|---|---|
| New OEM | $1,100 - $1,200 (when available) | This part is discontinued by Infiniti and no longer available new. |
| Used OEM | $50 - $150 | Price depends on the seller and condition. This is the most common option. |
| Remanufactured/Rebuilt OEM | $150 - $300 | These units have been tested and had common failure components like capacitors replaced. |
| Shop Labor for Replacement | $100 - $250 | Estimated 1-2 hours of labor for a professional to access and replace the module. |
Frequently Asked Questions (FAQ)
Does the 1990-1996 Q45 power steering module need to be programmed?
No. This is a plug-and-play module that does not require any programming or special calibration after installation.
How do I know if my Q45 has the Full-Active Suspension (FAS)?
Models with this option were designated "Q45A" and often had a "Full-Active Suspension" sticker on the rear window. It was a rare and expensive option offered from 1991-1995. If you are unsure, you can have an Infiniti dealer or a knowledgeable mechanic check your VIN. Most Q45s have the standard suspension.
Is it the module, the pump, or the steering rack?
It can be difficult to tell. A whining noise that changes with engine RPM usually points to the power steering pump. A notchy or binding feeling in the steering, especially when first starting the car, can be the steering U-joint. A complete or intermittent loss of assist without noise is often the control module or the solenoid on the rack it controls.
Where is the power steering control module located?
It is located inside the car, behind the radio in the center of the dashboard.
Technical Specifications
OEM Part Numbers: 28500-60U10 2850060U10
Controls speed-sensitive hydraulic power steering system. Not compatible with Full-Active Suspension (FAS) models.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- INFINITI Q45:
- 🛍️ Shop This Part
- Symptoms of a Failing Power Steering Control Module
- Vehicle Compatibility: The Active Suspension Question
- Buying a Used Power Steering Control Module
- Diagnosis and Replacement
- Location
- Programming and Installation
- Known Issues, TSBs, and Recalls
- Cost Comparison
- Frequently Asked Questions (FAQ)
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