2015 Honda Civic: Serpentine Belt Replacement Guide

An essential component of your 2015 Honda Civic's engine is the serpentine belt. This long, multi-ribbed belt drives multiple accessories simultaneously, including the alternator, A/C compressor, and water pump. Because it powers these critical systems, a failing belt can leave you stranded.

This guide will provide the part numbers, routing diagram, and replacement information you need to tackle a serpentine belt replacement on your 2015 Civic. Note that Honda offered two primary engines this model year—a 1.8L four-cylinder in most trims and a 2.4L four-cylinder in the performance-oriented Si model. Part numbers and routing differ between them.

Disclaimer: Part numbers can vary based on the specific manufacturing date, trim, and engine of your vehicle. Always verify the correct part number using your vehicle's VIN with a trusted parts supplier before purchasing.

Quick Answer: 2015 Civic Serpentine Belt PNs & Specs

Here are the common specifications and part numbers for the two main engine options.

For 1.8L Engine (LX, SE, EX, EX-L)

• Belt Length & Rib Count: Approx. 1330mm (52.4 inches), 6-rib
• OEM Belt PN: Honda 31110-R1A-A11
• Aftermarket Belt Cross-References: Gates K060525, Dayco 5060525, Continental 4060525
• Auto-Tensioner Assembly PN: Honda 31170-R1A-A01
• Idler Pulley: The 1.8L engine does not use a separate idler pulley. The tensioner pulley serves this function.

For 2.4L Engine (Si Model)

• Belt Length & Rib Count: Approx. 1435mm (56.5 inches), 7-rib
• OEM Belt PN: Honda 31110-RX0-A01
• Aftermarket Belt Cross-References: Gates K070565, Dayco 5070565, Continental 4070565
• Auto-Tensioner Assembly PN: Honda 31170-RX0-A01
• Idler Pulley PN: Honda 31190-RX0-A01

Belt Routing

Since it's impossible to render a diagram here, a text-based description is the next best thing. Before you remove the old belt, take a clear photograph of the routing path for reference. This simple step can save you a significant headache.

The 9th generation Civic uses Electric Power Steering (EPS), so you will not find a power steering pump on the belt path.

1.8L Engine Belt Routing

The belt snakes around five pulleys. Starting from the bottom-most pulley:

1. From the Crankshaft pulley (bottom center),
2. Up and around the A/C Compressor pulley (bottom right),
3. Up and over the Alternator pulley (top right),
4. Across to the Water Pump pulley (top left),
5. Down and around the Auto-Tensioner pulley (center left), returning to the Crankshaft.

2.4L (Si) Engine Belt Routing

The 2.4L engine adds an idler pulley into the system:

1. From the Crankshaft pulley (bottom center),
2. Up and around the A/C Compressor pulley (bottom right),
3. Up to the Idler Pulley,
4. Over the Alternator pulley (top right),
5. Across to the Water Pump pulley (top left),
6. Down and around the Auto-Tensioner pulley (center), returning to the Crankshaft.

How to Replace the Serpentine Belt

To replace the belt, you must release the tension from the auto-tensioner. You will need a serpentine belt tool or a long-handled 3/8-inch breaker bar. The tensioner has a square hole designed to accept the tool.

1. Insert the breaker bar or serpentine belt tool into the square hole on the body of the tensioner assembly.
2. Rotate the tensioner clockwise. This will retract the pulley and loosen the belt.
3. While holding the tensioner in the loosened position, slip the old belt off the smoothest, most accessible pulley (the water pump or alternator pulley is often easiest).
4. Slowly release the tool and the tensioner arm will return to its resting position.
5. Remove the old belt completely.
6. Route the new belt around all pulleys except for the last smooth one, using your photo and the path described above for guidance. Ensure the ribbed side of the belt is seated in the grooves of the crank, A/C, and alternator pulleys.
7. Rotate the tensioner again and slip the belt over the final pulley.
8. Slowly release the tensioner and ensure the belt is properly seated in every groove on every pulley. A misaligned belt will shred itself almost immediately.

Replacement Interval

Modern serpentine belts are durable, but they don't last forever. A general rule of thumb is to inspect the belt at every oil change and plan for replacement every 60,000 to 100,000 miles. Refer to your owner's manual for Honda's specific recommendation. It's often wise to replace the auto-tensioner and idler pulley (if equipped) at the same time as the belt, as their internal springs and pulley bearings wear out over time.

Signs of a Failing Belt or Tensioner

• High-pitched squealing or chirping: This noise is most common on cold starts or when turning on the A/C. It indicates a slipping belt.
• Visible wear: Look for cracks, fraying, glazing (shiny spots), or missing chunks or ribs on the belt.
• Grinding or rattling noise: A persistent grinding or rattling from the belt area often points to a failing bearing in the tensioner or idler pulley.
• Tensioner arm vibration: A tensioner arm that is vibrating erratically or "slapping" back and forth is a sign that its internal damping has failed.

If you're not comfortable performing this service yourself, Repairius can help.

Find a trusted shop on Repairius.