🔧 GS350 - Power Steering Pump Replacement (Not Applicable: EPS System)

Your GS350 uses an Electric Power Steering (EPS) system, which means there is no hydraulic power steering pump, no belt-driven pump, and typically no power steering fluid reservoir. If you’re having “no assist,” heavy steering, or warning lights, the fix is usually in the EPS electrical system (battery/charging, fuses, wiring, EPS rack/motor, or calibration), not a pump.

Difficulty Level: Intermediate | Estimated Time: 0.5-2.0 hours (diagnosis/checks)

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⚠️ Safety & Precautions

• ⚠️ Use jack stands anytime the front wheels are off the ground.
• ⚠️ Keep hands clear of the steering linkage if someone turns the wheel.
• ⚠️ If disconnecting the battery: protect memory settings and wait 90+ seconds before working near airbags (steering column area).
• ⚠️ Do not probe yellow airbag connectors with a meter.

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🔧 Required Tools

You'll need the following tools for this repair:

• OBD2 scan tool with Toyota/Lexus EPS capability (Techstream-compatible) (specialty)
• Digital multimeter
• 12V battery load tester (specialty)
• 10mm socket
• 12mm socket
• 14mm socket
• 3/8" drive ratchet
• 3/8" drive torque wrench
• Trim clip removal tool
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Safety glasses
• Nitrile gloves
• Flashlight

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• EPS-related fuses (assortment) - Qty: 1
• 12V battery (AGM or OEM equivalent) - Qty: 1
• Battery terminal cleaning kit - Qty: 1
• Steering rack assembly (EPS) - Qty: 1 (only if diagnosed failed)
• Front inner/outer tie rod set - Qty: 1 (recommended if rack is replaced)

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📋 Before You Begin

• Park on level ground, steering wheel centered, and set the parking brake.
• Chock the rear wheels using wheel chocks.
• If you will lift the front: loosen nothing yet—just plan safe lift points with a floor jack and support on jack stands.
• Have your scan tool ready to read EPS codes (these are different from engine codes).

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Confirm it’s EPS (no pump to replace)

• Open the hood and look for a power steering fluid reservoir (a small tank with a cap labeled “Power Steering”).
• If you do not see one, that confirms the EPS setup (electric assist), meaning there is no pump replacement procedure for your GS350.
• EPS = electric motor does the assisting.

Step 2: Check the 12V battery and charging basics (most common cause of EPS issues)

• Use a 12V battery load tester (specialty) to test the battery health per the tester instructions.
• Use a digital multimeter at the battery terminals:
  • Engine off: note voltage.
  • Engine running: note voltage again (charging check).
• If battery terminals are crusty/green, remove with a 10mm socket, clean, and reinstall snugly.
• Low voltage can disable steering assist.

Step 3: Scan for EPS trouble codes (this points to the real failed part)

• Plug in your OBD2 scan tool with Toyota/Lexus EPS capability (Techstream-compatible) (specialty).
• Read codes from the Power Steering / EPS module (not just “Engine”).
• Save or write down the codes and freeze frame data.
• Clear codes, then re-check after a short key cycle to see what returns immediately.

Step 4: Check EPS-related fuses (simple, fast win)

• Using a flashlight and trim clip removal tool, open the under-hood fuse box cover.
• Use the fuse box legend to locate EPS/PS-related fuses.
• Test fuses with a digital multimeter (continuity) instead of guessing by sight.
• Replace failed fuses with matching amperage from your EPS-related fuses (assortment).

Step 5: Front-end quick mechanical check (rule out binding)

• Lift the front safely using a floor jack (rated 3-ton minimum) and support with jack stands (rated 3-ton minimum).
• With the key OFF, turn each front wheel by hand and feel for roughness or binding.
• Check tire pressure (very low pressure can feel like “no power steering”).

Step 6: If codes indicate rack/motor failure, plan rack replacement + calibration

• The EPS assist motor is typically part of the steering rack assembly (EPS).
• Rack replacement is an advanced job and requires an alignment afterward, plus scan-tool calibrations (steering angle/zero point) depending on what codes are stored.
• If you proceed with rack replacement, you’ll also want front inner/outer tie rod set on hand.
• Don’t skip alignment—handling will suffer.

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✅ After Repair

• Re-scan with your OBD2 scan tool with Toyota/Lexus EPS capability (Techstream-compatible) (specialty) and confirm no EPS codes return.
• Road test in a safe area: verify steering assist at parking-lot speeds and no warning lights.
• If any steering or suspension parts were replaced: get a 4-wheel alignment.
• If the battery was disconnected: reset clock and one-touch window functions if needed.

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💰 DIY vs Shop Cost

Shop Cost: $150-$350 (diagnosis) OR $1,800-$3,500 (EPS rack replacement parts + labor + alignment)

DIY Cost: $0-$250 (battery/fuses/cleaning) OR $900-$2,200 (rack parts only, if needed)

You Save: $150-$1,300+ by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1-5 hours depending on diagnosis vs rack replacement.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.