🔧 Ascent - Ignition Coil Replacement

Replace the failed coil one cylinder at a time. Your Ascent has four coil-on-plug units, meaning each spark plug has its own ignition coil mounted directly over it.

The job is straightforward, but access beside the flat-four engine is tight. The battery-side coils usually require removing the battery, while the opposite side may require moving the intake duct or air-filter housing.

Difficulty Level: Intermediate | Estimated Time: 1-2 hours

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⚠️ Safety & Precautions

• 🛑 Let the engine cool completely because the turbocharger and exhaust components become extremely hot.
• 🔋 Disconnect the negative battery cable before unplugging the ignition coils.
• ⚡ Never run the engine with a loose coil near metal. Ignition voltage can cause a painful shock.
• 🧤 Pull electrical connectors by their plastic bodies, never by their wires.
• 🛑 Keep dirt and loose hardware away from the spark-plug openings.
• ⚠️ Do not overtighten the small coil bolts. They thread into aluminum.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 12mm socket
• 1/4-inch drive ratchet
• 1/4-inch drive torque wrench rated in inch-pounds
• 3-inch socket extension
• 6-inch socket extension
• Universal-joint socket adapter
• Flat-blade screwdriver
• Plastic trim-clip removal tool
• Needle-nose pliers
• Compressed-air blow gun
• LED work light
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Vehicle-specific ignition coil - Qty: 1 for the failed cylinder
• Vehicle-specific ignition coils - Qty: 4 if replacing the complete set
• Dielectric boot grease - Qty: 1 small tube

Important: The currently displayed coil carries a January 2020-and-later qualifier, so I would not order it for your 2019 until the catalog shows an unqualified 2019 fit. A shiny new wrong part is still a wrong part.

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📋 Before You Begin

• 🚙 Park your Ascent on level ground, select Park, set the parking brake, and switch the ignition off.
• 🌡️ Allow the engine to cool for at least one hour.
• 📷 Photograph the intake duct, battery cables, and wiring positions before disassembly.
• 🔍 If you have a diagnostic scanner, record the misfire code before clearing it. P0301 through P0304 identify the affected cylinder.
• 🧹 Clean loose dirt from both sides of the engine before removing a coil.
• 🔑 Keep the key away from the vehicle while electrical connectors are disconnected.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect the Battery

• Use the 10mm socket and 1/4-inch ratchet to loosen the negative battery-terminal nut.
• Lift the negative terminal from the battery post and position it where it cannot spring back.
• Do not allow a tool to bridge the positive terminal and vehicle body.

Step 2: Remove the Engine Cover

• Grip the plastic engine cover near its mounting points.
• Pull it straight upward by hand to release its rubber grommets.
• Place it somewhere clean so the mounting grommets are not lost.

Step 3: Open Access on the Battery Side

• Use the 10mm socket and ratchet to remove the battery hold-down fasteners.
• Disconnect the positive terminal with the 10mm socket after confirming the negative cable is already disconnected.
• Lift the battery straight upward using both hands. Batteries are heavy, so keep it upright.
• Remove the battery tray fasteners with the 10mm or 12mm socket if additional clearance is necessary.
• Put removed fasteners into labeled containers.

Step 4: Open Access on the Opposite Side

• Use the plastic trim-clip removal tool to release clips securing the intake snorkel.
• Use the flat-blade screwdriver to loosen an intake-hose clamp only if the air-filter housing blocks the coil.
• Use the 10mm socket and ratchet to remove airbox fasteners as required.
• Disconnect only the hoses and electrical connectors needed for clearance.
• Cover any open intake hose with a clean, lint-free cloth.

Step 5: Clean Around the Coil

• Wear safety glasses.
• Use the compressed-air blow gun to remove dirt around the coil and spark-plug tube.
• Use the LED work light to inspect the area for oil, coolant, or damaged wiring.
• If oil is present inside the spark-plug tube, stop and repair the sealing leak before fitting the new coil.

Step 6: Disconnect the Ignition Coil

• Press the electrical connector's locking tab with your fingers.
• Pull the connector body straight away from the coil.
• Use the flat-blade screwdriver only to gently depress a stubborn tab. Do not pry against the wires.
• Inspect the connector for corrosion, overheated terminals, or a broken lock.

Step 7: Remove the Old Coil

• Use the 10mm socket, extension, and 1/4-inch ratchet to remove the coil hold-down bolt.
• Rotate the coil gently to release its rubber boot from the spark plug.
• Pull the coil outward from the cylinder head. Slightly angle it as needed for body clearance.
• Inspect the boot for oil, water, cracking, carbon tracking, or burn marks.

Step 8: Install the Replacement Coil

• Compare the electrical connector, boot length, mounting ear, and overall shape with the removed coil.
• Apply only a thin film of dielectric grease inside the end of the rubber boot. Dielectric grease is an insulating silicone grease that seals out moisture.
• Do not place grease on the coil's electrical terminals or directly on the spark-plug metal contact.
• Push the coil squarely onto the spark plug until it is fully seated.
• Start the hold-down bolt by hand to prevent cross-threading.
• Use the inch-pound torque wrench and 10mm socket to tighten the bolt to 7.5 Nm (66 in-lbs). howtoo.com

Step 9: Reconnect the Coil

• Push the electrical connector onto the coil until its lock clicks.
• Gently pull the connector body to verify that it is locked.
• Check that the wiring is not stretched, pinched, or touching a hot component.

Step 10: Replace Additional Coils

• Repeat Steps 5 through 9 for each additional coil.
• Work on only one coil at a time so the connectors cannot be mixed up.
• If one coil failed but the others test correctly, replacing only the failed coil is normally acceptable.

Step 11: Reassemble the Intake Components

• Remove the protective cloth from any intake opening.
• Reinstall the air-filter housing and intake duct using the 10mm socket, ratchet, flat-blade screwdriver, and trim-clip removal tool.
• Reconnect every hose and electrical connector removed for access.
• Make sure intake hoses sit fully over their fittings before tightening their clamps.

Step 12: Reinstall the Battery

• Place the battery squarely in its tray using both hands.
• Reinstall the hold-down using the 10mm socket and ratchet. Tighten it only until the battery cannot move.
• Connect the positive terminal first, followed by the negative terminal.
• Tighten each terminal with the 10mm socket until secure. Do not crush or distort the terminal clamps.
• Press the engine cover down by hand until all mounting grommets engage.

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✅ After Repair

• 🚗 Start the engine and allow it to idle without pressing the accelerator.
• 👂 Listen for smooth operation, intake-air leaks, clicking, or an obvious misfire.
• 🔍 Confirm that no tools, cloths, or loose connectors remain in the engine compartment.
• 🧰 Use a diagnostic scanner to clear the misfire code, then recheck for returning codes after a road test.
• ⚠️ If the check-engine light flashes or the engine shakes badly, switch it off immediately and recheck the coil connectors.
• 🪟 Restore the automatic window function if necessary by fully lowering each affected window, then fully raising it and holding the switch for approximately one second.
• 🛣️ Take a gentle 10-15 minute test drive and scan again for pending misfire codes.
• 🔄 If the same cylinder still misfires, inspect the spark plug and wiring before buying more coils. Fuel-injector or compression faults can produce the same code.

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💰 DIY vs Shop Cost

Shop Cost: ₹12,000-₹35,000 for one or more coils, diagnosis, and labor

DIY Cost: ₹5,000-₹24,000 depending on coil quantity and brand

You Save: Approximately ₹5,000-₹12,000 by doing it yourself!

Labor and imported-part prices vary around Haryana. This repair usually takes a shop approximately 1-1.5 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every eligible part, plus all the tools and specialty tools you need! Check the parts and tools sections below, but verify that the ignition coil listing explicitly covers the 2019 model before adding it to your cart.