Failed ignition coil for cylinder 4 (open or shorted primary winding); Damaged or corroded electrical connector at the cylinder 4 coil; Broken, chafed, or open wire in the coil primary feedback circuit; Faulty powertrain control module (PCM) driver for the coil feedback circuit; Poor ground connection shared by the ignition coil circuit; Aftermarket or incorrect coil that does not produce the expected feedback signal

DTC codes / Chrysler codes / P1315

P1315 · ChryslerIgnition Coil 4 Primary Feedback Circuit

Q: What does code P1315 mean?

Ignition Coil 4 Primary Feedback Circuit. P1315 is a Chrysler-specific code that the powertrain control module (PCM) sets when the ignition coil for cylinder 4 fails to provide the expected primary feedback signal during the coil's firing event. The PCM monitors the primary circuit's voltage or current signature and flags this code when the feedback does not match the commanded dwell and firing profile, indicating an open, shorted, or otherwise faulty primary circuit or coil.

P1315 is a Chrysler-specific code that the powertrain control module (PCM) sets when the ignition coil for cylinder 4 fails to provide the expected primary feedback signal during the coil's firing event. The PCM monitors the primary circuit's voltage or current signature and flags this code when the feedback does not match the commanded dwell and firing profile, indicating an open, shorted, or otherwise faulty primary circuit or coil.

SystemPowertrain

Code typeChrysler 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 misfire felt as a shake or stumble, especially when the engine is cold
Reduced engine power or hesitation during acceleration
Increased fuel consumption due to incomplete combustion in cylinder 4
Possible flashing check engine light if the misfire is severe enough to damage the catalytic converter

Common causes, most likely first

Failed ignition coil for cylinder 4 (open or shorted primary winding)
Damaged or corroded electrical connector at the cylinder 4 coil
Broken, chafed, or open wire in the coil primary feedback circuit
Faulty powertrain control module (PCM) driver for the coil feedback circuit
Poor ground connection shared by the ignition coil circuit
Aftermarket or incorrect coil that does not produce the expected feedback signal

How to diagnose and fix it

Scan all modules and record freeze-frame data to confirm P1315 is the only coil-related code and note engine conditions at set
Inspect the cylinder 4 coil connector and wiring for corrosion, loose pins, or chafing, and repair as needed
Swap the cylinder 4 coil with a known-good coil from another cylinder and see if the code moves to confirm coil failure
Measure resistance of the cylinder 4 coil primary and secondary windings and compare to the manufacturer's specification
Back-probe the feedback circuit at the PCM and check for the expected voltage or current pulse during cranking and running
Check for continuity and short-to-ground on the feedback wire between the coil and PCM, repairing any open or short
If wiring and coil are good, test the PCM driver circuit or substitute a known-good PCM to rule out internal driver failure

Why cylinder 4 coil feedback fails

A coil that ohms out perfectly on the bench can still set P1315 because the PCM monitors dynamic feedback during firing, not static resistance, so a coil that fails only when hot or under load is easily missed.
Corroded terminals inside the coil connector often cause this code without any visible damage to the coil itself, and simply cleaning and re-tensioning the pins can resolve the fault.
The feedback circuit is a low-current signal wire that is easily damaged by careless probing; back-probing with a sharp pin can spread terminals and create the very fault you are chasing.
On some Chrysler engines, a failing camshaft or crankshaft sensor can disrupt the timing reference the PCM uses to validate coil feedback, setting P1315 even though the coil circuit is intact.
Replacing the coil without checking the feedback wire continuity is the most common misdiagnosis; the new coil will not fix an open wire between the coil and PCM.

Can I keep driving with P1315?

You can usually drive the vehicle short distances with P1315, but avoid heavy acceleration and prolonged driving because a persistent misfire can overheat and damage the catalytic converter. If the check engine light is flashing, stop driving and have the fault diagnosed immediately.

Tools that help

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