Parts for your 2015 Ford Territory-Ignition coils

2015 Ford Territory ignition coils — what they do and when they matter

Technical references indicate the 2015 Ford Territory can be fitted with ignition coils only when it has the 4.0‑litre petrol inline‑six. Ford Australia’s SZ/SZ MkII Territory workshop information (Engine 303‑07A: Ignition — 4.0L I6) specifies a coil‑on‑plug system, one coil per cylinder. By contrast, the 2.7‑litre TDCi diesel (Engine 303‑04C: Compression‑Ignition Fuel System) relies on compression ignition with glow plugs and a high‑pressure common‑rail injection system, so there’s no spark system and no ignition coils. Industry texts on the Ford/PSA AJD‑V6 diesel architecture and common‑rail operation support this. So, coils are relevant for 2015 Territory petrol models, and not used on the 2.7 TDCi diesel.

For petrol models, the ignition coils are the little powerhouses that transform the battery’s 12 volts into the high voltage needed to fire the spark plugs. On the Territory’s 4.0L I6 they’re coil‑on‑plug units, tucked neatly under the plastic engine cover, each sitting directly over a spark plug. Healthy coils mean clean starts, smooth running and decent fuel economy, tired ones lead to misfires, rough idle and that pesky check‑engine light.

There isn’t a strict replacement interval for coils. A good rule is to inspect them whenever the spark plugs are due (often around 100,000 km for long‑life plugs, or as per the service book). If the vehicle shows misfire codes (like P0301–P0306) or stumbles under load, a coil test or swap‑diagnosis can quickly pinpoint a dud. At higher mileages, if one fails, many owners choose to replace the full set to keep things consistent.

When fitting new coils, use quality parts and keep the plug wells clean and dry. A light smear of dielectric grease on the coil boots helps prevent tracking and eases future removal. Seat the coils squarely, reconnect the plugs firmly, and tighten fasteners to the workshop‑manual spec. Pairing fresh coils with new spark plugs can restore performance and help fuel economy if the old components were on their last legs.

Helpful signs to watch for:

• Rough idle, hesitation, or a stumble when overtaking
• Poor fuel economy and sluggish performance
• Check‑engine light with cylinder‑specific misfire codes

Handy tips between services:

• Avoid pressure‑washing the engine bay, water in plug tubes can upset coils
• If removing coils, label them to keep track and don’t mix up connectors
• Scan for codes before and after work to confirm a proper fix

FAQs

Does a 2015 Ford Territory have ignition coils?
Yes on the 4.0L petrol inline‑six (coil‑on‑plug, six units). The 2.7L TDCi diesel doesn’t use ignition coils at all because it’s a compression‑ignition engine with glow plugs and high‑pressure fuel injection.

How often should ignition coils be replaced?
There’s no fixed schedule. Inspect coils whenever spark plugs are serviced and replace any that fail testing or show misfire symptoms. If one coil fails at high kilometres, many technicians recommend replacing the set to keep performance even.

What are common symptoms of a failing ignition coil?
Rough idle, misfire under load, increased fuel use, hard starts, and a check‑engine light with cylinder‑specific misfire codes. On wet days, a weak coil may act up more due to moisture tracking.