2012 Ford Fusion Serpentine Belt Diagram: Routing by Engine
Your 2012 Ford Fusion uses one of four different serpentine belt setups. The exact one depends on your engine: 2.5L four-cylinder, 2.5L Hybrid, 3.0L V6 or 3.5L V6. The belt part number, the pulley it comes off, and the direction you turn the tensioner all change between them.
Ford’s own workshop manual confirms this split. Two of the four engines release with a clockwise turn of the tensioner. The other two release counterclockwise.
Turn the wrong direction and the tool just loads the spring harder instead of releasing it.
What engines does the 2012 Ford Fusion take, and why does it matter for the belt?
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The 2012 Fusion lineup covers four powertrains. The 2.5L Duratec four-cylinder, and the 2.5L Atkinson-cycle engine in the Fusion Hybrid.
Then the 3.0L Duratec V6, Flex Fuel capable and available with AWD. And the 3.5L Duratec V6 in the Sport trim, also AWD.
Each sits in the same engine bay footprint. Ford still built a separate accessory drive, called the Front End Accessory Drive or FEAD, for each one.
That split runs deeper than belt length. The 2.5L and the 3.0L use Electronic Power-Assisted Steering, or EPAS: an electric motor on the rack, no hydraulic pump.
The 3.5L V6 kept a traditional hydraulic power steering pump, driven off the belt. A steering complaint on a 3.5L can be a belt problem. On a 2.5L or 3.0L, it cannot.
Most belt diagram sites publish one generic routing graphic for “the Ford Fusion.” They note the specs “may vary slightly” between the 2.5L, 3.0L and 3.5L.
They do not vary slightly. They are opposite.
Ford’s factory manual has the 2.5L gas engine’s tensioner turning clockwise. The belt comes off the coolant pump pulley.
The 2.5L Hybrid, built the same model year, turns counterclockwise instead. It comes off the tensioner pulley itself, with a high-voltage safety step first. The 3.0L V6 also turns counterclockwise.
The 3.5L V6 turns clockwise again, but its mounting bolts torque to less than half of what the other three specify. Confirm your exact engine before you touch a wrench, not after.
2012 Ford Fusion serpentine belt chart: part numbers, routing and tensioner specs by engine
The belt part numbers below are Ford’s own Motorcraft and OEM numbers. They are confirmed against Ford’s dealer parts catalog and cross-checked against an independent Motorcraft cross-reference. Tensioner direction, bolt count and torque come straight from Ford’s 2012 Fusion factory workshop manual, read separately for each engine.
| Engine | Belt drives | Ford belt part number | Tensioner turns to release | Comes off which pulley | Mounting bolts / torque |
|---|---|---|---|---|---|
| 2.5L I4 Duratec (gas) | Alternator, A/C compressor, coolant pump. EPAS, no belt-driven steering. | AE5Z-8620-A (2010-2012) | Clockwise, using the tensioner’s hex feature | Coolant pump pulley | 2 bolts, 25 Nm (18 lb-ft) |
| 2.5L I4 Hybrid (Atkinson) | Alternator, A/C compressor, coolant pump. EPAS. High-voltage system nearby. | 9E5Z-8620-A (2010-2012) | Counterclockwise | Tensioner pulley itself | 3 bolts, 25 Nm (18 lb-ft) |
| 3.0L V6 Duratec (Flex Fuel) | Alternator, A/C compressor, coolant pump on a second belt. EPAS, no belt-driven steering. | GB5Z-8620-A main drive (2010-2012); 9L8Z-8620-A water pump belt | Counterclockwise | Tensioner pulley itself | 3 bolts, 25 Nm (18 lb-ft) |
| 3.5L V6 Duratec (Sport, AWD) | Alternator, A/C compressor, coolant pump, hydraulic power steering pump. | 7T4Z-8620-A, later 7T4Z-8620-C, replaced by BT4Z-8620-A (2007-2012) | Clockwise, working from the top of the vehicle | Generator (alternator) pulley | 3 bolts, 11 Nm (97 lb-in) |
The 3.0L is the only 2012 Fusion engine with two separate belts. A main accessory drive belt, GB5Z-8620-A, and a dedicated coolant pump belt, 9L8Z-8620-A, listed on its own in Ford’s parts catalog.
The 2.5L, 2.5L Hybrid and 3.5L each run a single combined belt, with no second one listed anywhere.
Which way does the tensioner actually turn on your engine?
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All four need the right-hand fender splash shield out first. That is 4 screws, then 6 pin-type retainers, straight from Ford’s own procedure.
A shop hoist lifts the whole car, so the manual skips wheel removal. A home driveway job means jacking the front passenger corner and pulling the wheel to reach those fasteners.
Owner reports on Fusion and Milan forums confirm the same access point on the 3.0L and 3.5L. Right front wheel off, splash shield out, tight clearance to the frame rail.
From there, the direction split holds exactly as the chart above shows. Turn the wrong way and the tensioner loads harder instead of releasing. If you feel resistance building instead of slack appearing within the first quarter turn, you have the direction backward for that engine.
The 2.5L Hybrid adds one step none of the others have. Ford’s procedure opens with depowering the vehicle’s high-voltage system.
Two high-voltage connectors near the tensioner get disconnected before the belt does. Skip that step at your own risk on a hybrid.
What does a bad serpentine belt sound and feel like on a 2012 Fusion?
Match your symptom to the likely cause before you start pulling parts. A few of these point at something other than the belt itself.
| What you notice | Most likely cause |
|---|---|
| High-pitched squeal at cold startup, fades after a few seconds | Glazed belt surface or a weak tensioner spring losing tension overnight |
| Squeal that gets worse only when the A/C is on | Belt slipping on the A/C compressor pulley, present on all four engines |
| Chirping that changes with steering input, 3.5L V6 only | Belt slipping under power steering pump load. Not possible on the 2.5L or 3.0L |
| Steering feels heavy, or an EPAS warning shows, on a 2.5L or 3.0L | Not a belt problem. EPAS runs off an electric motor, not the belt |
| Rhythmic flapping or thumping noise at idle | Belt too loose, or the automatic tensioner has lost its spring rate |
| Battery warning light plus dimming headlights | Belt slipping on the alternator pulley, or a snapped belt |
| Sudden overheating warning, no visible coolant loss | Snapped belt. On the 2.5L and Hybrid, the coolant pump rides the same belt and stops turning too |
| Cracking across the ribs, more than a few per inch | Belt is past its service life. EPDM belts crack less visibly than old neoprene, so flex a rib to check, don’t just look |
Does the 2012 Fusion have a belt-driven power steering pump?
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Only on the 3.5L V6. Ford’s parts catalog lists a power steering pump assembly, AH6Z-3A696-A or EU2Z-3V674-LRM, for the 2010-2012 Fusion 3.5L.
No equivalent hydraulic pump exists for the 2010-2012 3.0L. Ford’s own workshop manual files the 3.0L’s steering system under EPAS, the same electric-rack system as the 2.5L.
That is a real change from the Fusion’s first two model years. A 3.0L V6 sold in 2006 through 2009 did use a belt-driven hydraulic pump, and Ford’s parts catalog still lists that older pump on its own.
The 2010 refresh moved the 3.0L to EPAS. The 3.5L Sport kept hydraulic assist, inside the same generation this site groups as 2006-2012.
If your Fusion is a 3.0L, do not chase a steering noise into the belt. There is no steering pump on it to slip.
Which belt part number is correct, AE5Z-8620-A or 9E5Z-8620-A?
Ford’s own dealer parts network is not fully consistent with itself here. FordPartsGiant’s catalog lists AE5Z-8620-A under “4 Cyl 2.5L PFI Gas/Electric” and 9E5Z-8620-A under “4 Cyl 2.5L Duratec HE PFI.” That reads as AE5Z for the Hybrid.
Lakeland Ford’s own parts pages title 9E5Z-8620-A specifically “Fusion Hybrid Sedan.” They list AE5Z-8620-A under the plain “Fusion” pages for 2010, 2011 and 2012 instead. That is the opposite assignment.
Both part numbers are genuine Ford numbers covering the 2010-2012 2.5L engine family. Which one is correct for your specific Fusion cannot be resolved from published catalogs alone.
Have the parts counter confirm against your VIN before you order either one. That beats trusting either catalog’s category label.
Tools and parts for a 2012 Fusion belt job
Ford’s manual does not publish an exact socket size, only that the tensioner uses a “hex feature.” Owners on the 2.5L and V6 engines commonly report a 15mm socket fits.
A 3/8-inch or 1/2-inch drive ratchet turns it. That is field-reported, not a confirmed factory spec, so bring a small set and check what actually engages.
A dedicated serpentine belt tool kit gives you leverage a standard ratchet often cannot manage this close to the frame rail.
For the tensioner’s mounting bolts, torque them to the exact spec in the chart above rather than guessing. A small-scale torque wrench matters more here than on most under-hood bolts.
The 3.5L spec is less than half the other three. Overtightening it risks cracking the mounting boss.
Chasing a steering noise on the 3.5L specifically? Our Ford Fusion power steering assist fault reset guide covers the warning message this system throws on a real fault. That is separate from a belt-driven pump slipping.
Quick reference: 2012 Ford Fusion serpentine belt
| Engine | Tensioner direction | Belt part number | Power steering on belt? |
|---|---|---|---|
| 2.5L I4 (gas) | Clockwise | AE5Z-8620-A | No, EPAS |
| 2.5L I4 Hybrid | Counterclockwise | 9E5Z-8620-A | No, EPAS |
| 3.0L V6 | Counterclockwise | GB5Z-8620-A + 9L8Z-8620-A (2nd belt) | No, EPAS |
| 3.5L V6 | Clockwise | 7T4Z-8620-A / BT4Z-8620-A | Yes, hydraulic |
Have a different model year in this generation? The 2011 Ford Fusion serpentine belt diagram covers the year just before this one.
The 2014 Ford Fusion fuse box diagram covers the next generation’s electrical side. While the hood is already up, reset your oil life monitor too.
