You’re scanning a 2020 Mercedes-Benz A220 that’s been setting P0301 since breakfast. The owner swears it’s a bad injector because “a shop told them so.” But you pulled up live data, watched Cylinder 1’s misfire counter climb at idle, and saw the fuel trims go rich trying to compensate. Classic coil failure. Not the plug. Not the injector. The coil.
The engine is the M282 — the turbocharged 1.3L four-cylinder shared across a big slice of the current Mercedes-Benz lineup: A-Class, CLA, GLA. It’s a decent motor, but the ignition coils sit tight against a hot plastic cam cover, and heat cycling takes its toll. The OE replacement is A2829060000. If you’re doing this at shop pace, the coil you want on the bench is the OSRAM OS1308 — a direct-fit unit that skips the dealer markup without skipping the OEM-spec internals: OS1308 | OSRAM Ignition Coil | Fits Mercedes-Benz | OE# A2829060000 224332935R.
Here’s the walkthrough. It’s a forty-minute repair with the right prep, and a two-hour headache without it.
What You Actually Need
- 8mm socket and a short extension
- Torque wrench — yes, you need it
- Dielectric grease, a small tube
- Clean, lint-free rag
- OS1308 OSRAM coil(s)
No pry tools. No coil pullers. The M282 boots slide off with a firm twist.
The Replacement Sequence
1. Disconnect the battery negative terminal and wait five minutes. Do this before unplugging anything. The M282’s ECU holds live data in memory, and a sudden voltage spike while pulling a connector can send you chasing phantom codes.
2. Unclip the engine cover and set it aside. Six clips on the A-Class. Pull from the front and you’ll snap a tab.
3. Unplug each coil’s electrical connector. Press the red locking tab down, then squeeze the black slide. It comes free clean. If a terminal looks green or crusty, that’s your first clue someone else was in here before you.
4. Remove the coil bolts. The torque spec on the M282 coil bracket studs is 8 Nm. Not 10. Not 12. That spec exists because the coil bracket sits in an aluminum cam cover — 8 Nm holds the coil firmly without leaning on the boot. Going over is how you crack a mounting boss three months from now. Set the wrench. Use it.
5. Pull the coil straight up, twisting slightly as you lift. This breaks the boot suction around the spark plug. If the boot stays stuck on the plug, work a pick around the top edge to free it. Never lever underneath the coil body with a screwdriver — the plastic housing is reinforced, but it isn’t a pry bar.
6. Compare old vs new. Check boot spring length, the O-ring on the connector end, and both mounting holes. The OS1308 matches OE dimensions, but check anyway. It costs ten seconds.
7. Clean the boot seat. Wipe the recess in the cam cover where the coil sits. Dirt trapped under the coil body can cause arcing to the cylinder head. Cheap insurance.
8. Apply a thin film of dielectric grease inside the coil boot. That’s the only place it belongs. Not on the electrical pins. Not on the connector terminals. Just inside the silicone boot — so the next guy doesn’t have to fight a fused boot.
9. Press the coil into place until it clicks onto the spark plug. Hand-tight, then torque the bolt to 8 Nm.
10. Reconnect the harness connector until the red lock clicks. Reconnect the battery, clear the codes, and start the engine.
Common Mistakes to Avoid
The Number One mistake: replacing one coil and calling it done. Misfire codes on the M282 often move. Cylinder 1 misfires today, but the coil on Cylinder 3 has the same heat damage history. If all four coils are from the same batch and the car has over 40,000 miles, the smart play is replacing all four and quoting it that way upfront. Single-coil repair is fine if the others test clean and the customer is watching the budget — but warn them about the likely second visit.
Second mistake: over-torquing the coil bolt. It feels wrong leaving a bolt that “loose,” but 8 Nm is the spec. Trust the wrench.
Third mistake: ignoring the spark plug. You’re right there. The plug is exposed with the coil off. If it’s past 30,000 miles on an M282, show the electrode to the customer and suggest a fresh set. That’s not an upsell — that’s avoiding a return trip when a worn plug starts misfiring and the coil takes the blame.
Fourth: skipping a look at the intake boot while you’re in there. Vacuum leaks mimic coil failures on turbo engines. A lean misfire on one cylinder can look identical to a dead coil on live data. Two minutes with a smoke tester saves you a comeback.
How the OS1308 Performs
I’ve run the OSRAM unit on two shop cars — a GLA 250 and an A220, both M282. Fitment is identical to OE: same boot stiffness, same O-ring seal, same connector feel. It seats on the plug with a satisfying click, no wrestling required. One of those cars has done six months of daily duty with zero re-checks.
For the price, this is the coil to keep in stock. When the next M282 rolls in with a P0301 and the customer doesn’t want a four-coil job upfront, swap the bad cylinder’s coil, set the torque wrench to 8 Nm, and have the car out the door inside an hour. If the customer asks whether you’re using a “German brand” part, hand them the OSRAM box — OS1308 | OSRAM Ignition Coil | Fits Mercedes-Benz | OE# A2829060000 224332935R — and let the part do the talking.
