A 2017 KADJAR rolls into the bay with a rough idle that gets worse under load. Check engine light is on, and the owner says it started after a cold snap last week. He already swapped the battery because it was dead, but the misfire didn’t clear. Sound familiar? This is a textbook ignition coil call, but the symptoms can fool you if you don’t dig past the obvious.
Let me walk you through the diagnosis on this one, because ignition coil failures on the KADJAR—especially the 1.2 TCe and 1.6 petrol variants—have a few quirks worth knowing. And if you’re working on a VW or Skoda with a similar complaint, the same logic applies, just with different OE numbers.
Step 1: Read the Codes and Look for Patterns
First scan pulled a P0302 (cylinder 2 misfire) and a P0352 (ignition coil B primary/secondary circuit malfunction). That second code seals it—the coil itself has an internal fault, not just a spark plug issue. On the KADJAR, I’ve seen P0300 random misfire more often than a specific cylinder code when the coil starts degrading under heat. The owner’s dead battery symptom? That was likely a separate issue: parasitic drain from the misfire ECU getting confused and keeping relays alive, or just age. After a new battery, the misfire remained, which confirms the coil was the root cause all along.
Common fault codes on KADJAR ignition system:
- P0300 – Random/multiple cylinder misfire
- P0301–P0304 – Cylinder-specific misfire
- P0351–P0354 – Ignition coil primary/secondary circuit failure
- P130A – Cylinder 1 misfire with fuel cut (often misdiagnosed as injector)
Step 2: Distinguishing Coil Failure from Battery or Signal Interference
A dead battery can cause misfire codes, but the pattern is different. After a jump start or fresh battery, if the misfire clears after a few minutes and the code never returns, it was low voltage fooling the coil’s primary circuit. With a failed coil, the misfire persists even at full battery voltage.
Signal interference is rarer on the KADJAR, but I’ve seen aftermarket LED headlight ballasts and cheap USB chargers inject noise into the 12V rail. That can trigger false coil circuit faults. Check the wave form with a scope if you see intermittent misfire codes that move between cylinders. Grounding issues also mimic coil failure—clean the engine-to-chassis ground, especially on the 1.6 petrol where the ground strap corrodes near the battery tray.
Step 3: The OS1018 Option for VW and Skoda Applications
Now, the KADJAR uses a specific coil-on-plug design (Renault part number 22433-2921R or equivalent). But the diagnostic workflow is identical for any modern coil-on-plug system. If you’re working on a VW Golf or Skoda Octavia with the 1.4 TSI or 1.6 MPI and you see P0351 or P0301, the OS1018 | OSRAM Ignition Coil | Fits Skoda, [Volkswagen | OE# 036905715E
0986221023](https://longweiparts.com/product/os1018-osram-ignition-coil-fits-skoda-volkswagen-oe-036905715e0986221023/) is a direct OE replacement that I’ve used in a dozen shops. It’s OS1018 from OSRAM, matching OE# 036905715E / 0986221023.
Here’s why I reach for it: the moulded secondary boot has a snug fit that doesn’t tear on removal like some budget copies, and the primary resistance stays within spec longer. We’ve logged fewer comebacks than with the cheap grey-box units.
Pro Tip – Don’t Skip the Spark Plug Tube Check
Before you swap any ignition coil, pull the spark plug and inspect the tube for oil or coolant contamination. On the KADJAR 1.2 TCe, the cam cover gasket leaks into the plug holes, destroying the coil boot within months. Clean the tube, replace the gasket, and then install the new coil. Otherwise, you’ll be doing the job again in three months.
Step 4: Testing the Old Coil – Quick Bench Check
While you have the coil out, connect a multimeter to the primary terminals. You should see 0.5–1.5 ohms on most direct-ignition coils, including the OS1018. Secondary resistance (between the spark plug terminal and ground) should read 6–10 kΩ. If it’s open or shorted, the coil is toast. If it reads within spec but the vehicle still misfired, suspect an intermittent thermal failure—heat gun the coil to 80°C and re-test.
The Bottom Line for the Shop
For KADJAR owners: replace the faulty coil with the correct OE-grade part, and don’t forget the spark plugs (always do all four while the coils are off). For VW, Skoda, and Seat owners dealing with the same misfire codes, the [OS1018 | OSRAM Ignition Coil | Fits Skoda, Volkswagen | OE# 036905715E
0986221023](https://longweiparts.com/product/os1018-osram-ignition-coil-fits-skoda-volkswagen-oe-036905715e0986221023/) is a solid choice that won’t have you chasing intermittent faults six months down the road. Either way, the diagnostic path is the same: verify with codes, rule out battery and ground issues, then swap the coil. Keep a few of these OSRAM coils on the shelf; they pay for themselves in reduced diag time.
