Worn or fouled spark plugs in the affected cylinder group; Failed ignition coil or coil pack on one or more cylinders; Faulty spark plug wires or ignition harness connectors (on older models); Vacuum leak or intake manifold gasket failure affecting that cylinder bank; Low fuel pressure or clogged fuel injectors for the affected group; Mechanical issue such as low compression or valve problem on that bank

DTC codes / Jaguar codes / P1368

P1368 · JaguarIgnition System Failure Group 2

Q: What does code P1368 mean?

Ignition System Failure Group 2. P1368 on Jaguar vehicles indicates that the engine control module (ECM) has detected a misfire or ignition failure specifically affecting the second group of cylinders, often bank 2 or a defined set of cylinders depending on engine layout. The ECM monitors crankshaft speed fluctuations and compares them to expected values to identify which cylinder or group is not contributing power correctly.

P1368 on Jaguar vehicles indicates that the engine control module (ECM) has detected a misfire or ignition failure specifically affecting the second group of cylinders, often bank 2 or a defined set of cylinders depending on engine layout. The ECM monitors crankshaft speed fluctuations and compares them to expected values to identify which cylinder or group is not contributing power correctly.

SystemPowertrain

Code typeJaguar specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illuminated check engine light, often flashing if the misfire is severe
Noticeable engine misfire or rough running, especially under acceleration
Reduced engine power or limp mode activation
Shaking or vibration felt through the steering wheel or seat
Often no symptoms besides the warning light if the misfire is intermittent

Common causes, most likely first

Worn or fouled spark plugs in the affected cylinder group
Failed ignition coil or coil pack on one or more cylinders
Faulty spark plug wires or ignition harness connectors (on older models)
Vacuum leak or intake manifold gasket failure affecting that cylinder bank
Low fuel pressure or clogged fuel injectors for the affected group
Mechanical issue such as low compression or valve problem on that bank

How to diagnose and fix it

Scan all modules for stored and pending codes, and record freeze-frame data to identify the exact misfire conditions
Perform a visual inspection of ignition components (coils, plugs, wiring) on the affected cylinder group for damage or corrosion
Swap ignition coils from the affected group to a known-good cylinder to see if the misfire moves
Check spark plugs for wear, gap, and fouling; replace as needed
Test fuel injectors for resistance and pulse signal, and check fuel pressure
Perform a compression test or cylinder leak-down test on the affected cylinders to rule out mechanical faults
Repair any vacuum leaks or intake gasket issues found during smoke testing

Ignition Group 2 Misfire Diagnosis Tips

On many Jaguar V8 engines, group 2 refers to a specific set of cylinders (often bank 2), but always confirm with the factory service manual for your exact model year and engine code.
A flashing check engine light indicates a severe misfire that can damage the catalytic converter; stop driving immediately if this occurs.
Ignition coil failure is common on Jaguar AJ-V8 engines, but a misfire can also be caused by a faulty fuel injector or a vacuum leak that mimics ignition problems.
Do not overlook the possibility of a worn timing chain or variable valve timing issue on higher-mileage Jaguars, which can cause misfires without setting typical cam/crank codes.
After repairs, clear the codes and perform a drive cycle to ensure the misfire monitor completes and the light stays off.

Can I keep driving with P1368?

If the check engine light is steady, you can drive cautiously to a repair shop, but avoid hard acceleration and heavy loads. If the light is flashing, stop driving immediately and have the vehicle towed to prevent catalytic converter damage.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for Jaguar vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.