Faulty ignition coil on cylinder 6 with internal short or degraded insulation; Worn or fouled spark plug on cylinder 6 causing abnormal ionization and coil feedback; Damaged or corroded electrical connector at the cylinder 6 coil; Chafed or open wiring in the coil trigger circuit between the ECM and coil; Failed ignition coil driver inside the engine control module (less common); Contamination or moisture ingress into the coil boot or spark plug well

DTC codes / Jaguar codes / P1376

P1376 · JaguarIgnition Coil Cylinder 6 Early Activation Fault

Q: What does code P1376 mean?

Ignition Coil Cylinder 6 Early Activation Fault. P1376 on a Jaguar indicates the engine control module has detected that the ignition coil for cylinder 6 is activating earlier than expected relative to the commanded spark timing. The module monitors coil primary current and compares the actual dwell and firing event against the target, flagging this fault when the coil fires too soon, which can cause a misfire or rough running.

P1376 on a Jaguar indicates the engine control module has detected that the ignition coil for cylinder 6 is activating earlier than expected relative to the commanded spark timing. The module monitors coil primary current and compares the actual dwell and firing event against the target, flagging this fault when the coil fires too soon, which can cause a misfire or rough running.

SystemPowertrain

Code typeJaguar specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or engine vibration, especially when cold
Hesitation or stumble during acceleration
Reduced fuel economy due to incomplete combustion
Occasional misfire code for cylinder 6 stored alongside P1376
In severe cases, a flashing check engine light indicating a misfire that could damage the catalytic converter

Common causes, most likely first

Faulty ignition coil on cylinder 6 with internal short or degraded insulation
Worn or fouled spark plug on cylinder 6 causing abnormal ionization and coil feedback
Damaged or corroded electrical connector at the cylinder 6 coil
Chafed or open wiring in the coil trigger circuit between the ECM and coil
Failed ignition coil driver inside the engine control module (less common)
Contamination or moisture ingress into the coil boot or spark plug well

How to diagnose and fix it

Scan all modules for stored and pending codes, and record freeze-frame data to confirm the fault conditions
Inspect the cylinder 6 ignition coil, connector, and wiring for corrosion, chafing, or loose pins
Swap the cylinder 6 coil with a known-good coil from another cylinder and recheck for code migration
Remove and inspect the spark plug on cylinder 6 for wear, fouling, or incorrect gap; replace if necessary
Perform a resistance and waveform test on the coil trigger circuit to rule out wiring faults
If the fault persists after swapping components, test the ECM driver output with an oscilloscope or substitute a known-good ECM
Clear codes and road-test the vehicle under the same conditions that originally set the code to verify the repair

What a coil swap really tells you

Swapping the coil to another cylinder is the quickest way to confirm whether the fault follows the coil or stays with cylinder 6, which separates a bad coil from a wiring or ECM issue.
A spark plug with excessive gap or high resistance can cause the coil to fire early as the voltage builds faster than expected, so always inspect the plug before condemning the coil.
P1376 can be set intermittently by a loose coil connector that only loses contact during engine vibration, so wiggle-test the harness while monitoring live misfire data.
Jaguar's coil-on-plug design places the coil boot deep in the cam cover, where oil leaks from a failed gasket can soften the boot and cause early activation without any visible external damage.
This code does not always mean the coil is failing; a faulty ECM driver or a shorted trigger wire can command early activation, so circuit testing is essential before parts replacement.

Can I keep driving with P1376?

You can usually drive the car to a workshop, but avoid hard acceleration and prolonged driving if the check engine light is flashing, as a persistent misfire can overheat and damage the catalytic converter. If the engine runs very rough or loses power, stop and arrange a tow.

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.