🔧 Sonata - Fuel Pump Module Replacement

The fuel pump is part of a module installed inside the fuel tank beneath the rear seat. You will relieve fuel pressure, remove the seat and service cover, disconnect the module, and replace it without lowering the tank.

Difficulty Level: Intermediate | Estimated Time: 2-3 hours

Assumption: This procedure replaces the complete in-tank fuel pump module.

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⚠️ Safety & Precautions

• 🔥 Work outdoors or in a well-ventilated area, away from flames, heaters, cigarettes, and anything that can create a spark.
• 🧯 Keep a Class B fire extinguisher within reach.
• 🥽 Wear safety glasses and fuel-resistant nitrile gloves. Gasoline can cause serious eye and skin irritation.
• ⛽ Begin with the fuel tank below one-quarter full to reduce spilling.
• 🔋 Relieve fuel pressure before disconnecting the negative battery cable.
• ⚡ Do not use an impact wrench, steel punch, or ordinary hammer on the fuel-pump locking ring.
• 🚫 Do not energize the new pump while it is outside the fuel tank.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 12mm socket
• 3/8-inch drive ratchet
• 3/8-inch drive torque wrench rated 10-100 Nm
• 150mm socket extension
• Phillips No. 2 screwdriver
• Fuel pump lock-ring tool 09310-2S200 equivalent (specialty)
• Fuel-line disconnect pliers (specialty)
• Plastic trim-removal tool
• Plastic scraper
• Small flat-blade screwdriver
• Wet/dry vacuum rated for dry debris only
• Drain pan rated for gasoline
• Shop towels
• Fuel-resistant nitrile gloves
• Safety glasses
• Class B fire extinguisher

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Complete in-tank fuel pump module - Qty: 1
• Fuel pump module sealing gasket - Qty: 1
• Fuel pump service-cover sealant - Qty: 1
• Fuel-safe absorbent towels - Qty: 1 pack

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📋 Before You Begin

• 🚗 Park your Sonata outside on firm, level ground. Select Park, apply the parking brake, switch off the ignition, and open the rear doors.
• ⛽ Reduce the fuel level below one-quarter tank before beginning.
• 📱 Record any radio presets that you want to retain. No infotainment service mode or scan-tool command is required.
• 🧹 Clean loose dirt from beneath the rear seat before opening the fuel tank.
• 🔋 Do not disconnect the battery until the fuel-pressure relief step is complete.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the rear seat cushion

• Use the 12mm socket, 150mm extension, and ratchet to remove the two bolts along the lower front edge of the rear seat cushion.
• Push the cushion slightly rearward, then lift its front edge to release the retaining hooks.
• Guide the seat-belt buckles through the openings and remove the cushion through a rear door.
• Photograph buckle routing before removing the cushion.

Step 2: Expose the fuel pump connection

• Use the Phillips No. 2 screwdriver to remove the fuel-pump service-cover fasteners.
• If the cover is held by sealant, use the plastic trim-removal tool to lift it without bending it.
• Use the wet/dry vacuum rated for dry debris only to remove dry dirt around the cover. Do not vacuum gasoline or wet fuel residue.
• Lift the service cover and locate the fuel-pump electrical connector.

Step 3: Relieve the fuel-system pressure

• Press the electrical connector lock with the small flat-blade screwdriver and unplug the fuel-pump module connector.
• Start the engine and allow it to run until it stalls from lack of fuel.
• Crank the engine for approximately three seconds, then switch the ignition completely off.
• This removes most pressure from the line, but keep the shop towels around the connection because a small amount of gasoline will remain.

Step 4: Disconnect the battery

• Open the hood and use the 10mm socket and ratchet to loosen the negative battery-terminal clamp.
• Remove the negative cable and position it where it cannot touch the battery post.
• Wait at least one minute before continuing.

Step 5: Clean the module area

• Use the wet/dry vacuum rated for dry debris only to remove all remaining dry debris from the top of the module.
• Wipe the surrounding metal with shop towels. Dirt must not enter the tank.
• Place the drain pan rated for gasoline beside the opening to receive the old module.

Step 6: Disconnect the fuel line

• Wrap the connection with shop towels to catch residual gasoline.
• Release the quick connector’s safety lock with the small flat-blade screwdriver.
• Use the fuel-line disconnect pliers to press the connector tabs evenly, then pull the line straight off the module fitting.
• A quick connector is a reusable snap fitting; do not twist it forcefully or pry against the plastic fitting.
• Inspect the connector for cracks, damaged tabs, or a displaced internal seal.

Step 7: Remove the locking ring

• Fit the fuel pump lock-ring tool 09310-2S200 equivalent over the locking ring. This specialty tool grips the ring without creating sparks or damaging it.
• Use the 3/8-inch drive ratchet with the lock-ring tool to rotate the ring counterclockwise.
• Remove the locking ring and set it on a clean towel.
• Do not use a steel punch, chisel, or impact wrench.

Step 8: Remove the old fuel pump module

• Lift the module slowly by hand while holding shop towels around the opening.
• Tilt the module only enough to guide the fuel-level float through the opening without bending its arm.
• Allow trapped gasoline to drain into the tank, then place the module in the drain pan rated for gasoline.
• Remove the old sealing gasket from the tank opening with the plastic scraper.
• Do not drop debris or tools into the fuel tank.

Step 9: Install the new sealing gasket

• Use the plastic scraper and shop towels to clean the gasket seating surface.
• Install the new fuel pump module sealing gasket directly into the tank-opening groove.
• Do not reuse the old gasket or apply grease, silicone, or general-purpose sealant to it.

Step 10: Install the new fuel pump module

• Lower the module into the tank by hand, guiding the float carefully past the opening.
• Align the module’s index mark with the corresponding mark on the fuel tank.
• Keep downward pressure on the module so the gasket remains flat and does not become pinched.
• Install the locking ring by hand, then use the fuel pump lock-ring tool and 3/8-inch drive torque wrench to tighten it to 69-79 Nm (51-58 ft-lbs).
• Stop if the gasket begins squeezing outward.

Step 11: Reconnect the fuel line and wiring

• Push the fuel-line connector straight onto the module fitting by hand until it clicks.
• Reinstall its safety lock by hand, then pull gently on the line to verify it is secured.
• Connect the electrical plug by hand until its locking tab clicks.
• Confirm the wiring and fuel line are not twisted or trapped beneath the service cover.

Step 12: Prime and leak-check the system

• Use the 10mm socket and ratchet to reconnect the negative battery terminal. Tighten the clamp securely without crushing or overtightening it.
• Switch the ignition to ON without starting the engine for five seconds, then switch it OFF for ten seconds.
• Repeat that ON/OFF cycle three times to fill the new module and pressurize the line.
• Inspect the locking-ring seal and fuel-line connector using the safety glasses and shop towels. There must be no dampness, dripping, or fuel odor.
• If fuel appears, switch the ignition off immediately, disconnect the battery with the 10mm socket, and correct the connection before continuing.

Step 13: Start the engine

• Start the engine and let it idle for two minutes.
• Inspect the module opening again while wearing safety glasses.
• Confirm that the engine starts normally, idles smoothly, and no fuel leaks are present.

Step 14: Reinstall the service cover

• Switch off the engine.
• Use the plastic scraper to remove loose old cover sealant without damaging the painted floor.
• Apply the new fuel pump service-cover sealant around the cover’s original sealing path.
• Position the cover and use the Phillips No. 2 screwdriver to tighten its fasteners evenly until snug.

Step 15: Reinstall the rear seat cushion

• Pass the seat-belt buckles through their openings and position the rear edge of the cushion beneath the seatback.
• Press the cushion downward to engage its retaining hooks.
• Install the two front bolts using the 12mm socket and 150mm extension.
• Use the 3/8-inch drive torque wrench and 12mm socket to tighten the bolts to 20-30 Nm (15-22 ft-lbs).
• Pull upward on the cushion’s front edge to confirm it is locked in place.

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✅ After Repair

• ✅ Start your Sonata several times and verify that cranking time is normal.
• 👃 Check for gasoline odor around the rear seat and beneath the vehicle.
• 🔍 Recheck the service opening for leaks after a short drive and again after the next fuel fill.
• ⚠️ If the engine cranks but does not start, do not continue cranking. Recheck the module connector, fuel-line connection, and pump-module installation.
• 🛢️ Take the old module and captured gasoline to an authorized hazardous-waste facility. Never pour fuel onto the ground or into a drain.

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💰 DIY vs Shop Cost

Shop Cost: ₹28,000-₹55,000 (parts + labor)

DIY Cost: ₹14,000-₹32,000 (parts only)

You Save: ₹14,000-₹23,000 by doing it yourself!

Local labor rates and imported-part pricing vary. This repair takes a shop approximately 1.5-2.5 hours.

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