P1315 – Persistent Misfire: Symptoms, Causes, Diagnosis & Repair Cost (2026 Guide)

Overview

The control module stored P1315 because it detected a problem with: Persistent Misfire.

P1315 relates to Persistent Misfire. Use a quality scan tool, follow wiring diagrams for your vehicle, and confirm tests before replacing expensive parts.

What does the P1315 code mean?

When P1315 is set, the vehicle’s diagnostics detected an issue described as: Persistent Misfire. In practice, the ECM/PCM (and related modules) compare sensor inputs, commanded outputs, and self-tests for that subsystem. The exact repair depends on whether the fault is wiring-related, component-related, or a rationality/performance issue for this circuit or system.

Common symptoms of P1315

Check engine light
Unusual engine noise
Hard start
Loss of power
Rough running or misfire feel
Extended crank

Possible causes

Fault affecting Persistent Misfire (wiring, connector, or component)
Component failure in the described system
Control module strategy or calibration issue
Electrical fault in the monitored circuit
Control module or software calibration issue (less common—verify tests first)
Past repairs or aftermarket parts causing out-of-spec operation

How to diagnose P1315

Scan for P1315 and review freeze frame / pending codes for related faults
Inspect connectors and wiring related to: Persistent Misfire
Compare live data and commanded vs actual values for the affected system (per service information)
Perform circuit tests appropriate to the fault type (continuity, voltage, resistance) before replacing parts
Confirm power and ground integrity at the relevant module or sensor
After repair, clear DTCs and verify under the conditions that originally set P1315

Tip: Use a scan tool that shows live data and freeze frame for the conditions when the code set.

Severity of code P1315

High: This code can affect emissions, performance, or drivability. Diagnose before long trips or heavy loads.

Can you drive with P1315?

Short trips may be okay if the vehicle feels normal, but have it diagnosed—especially if performance, safety warnings, or overheating are present.

Avoid heavy acceleration, towing, or long highway drives until the cause of P1315 is confirmed and repaired.

How to fix it (step-by-step)

Start with visual inspection and connector cleaning/tightening where needed
Confirm failure mode with testing—avoid swapping parts without evidence
Repair wiring or replace the failed component per manufacturer procedure
Clear faults, run relearns if required, and road test to confirm

Repair & fix options

Test component against service limits
Inspect connectors and wiring first
Clear codes and verify with drive cycle
Clear codes and verify repair with a drive cycle and readiness where applicable
Reinspect related monitors if the code returns after repair

Typical repair cost

$120 – $3,500+ depending on cause

Estimated cost breakdown for P1315
Repair type	Typical range
Diagnostic And Minor	$180 – $900
Common Component Work	$800 – $3,500+
Major Subsystem Repair	$400 – $1,800
Severe Or Replacement	$120 – $1,200

How to help prevent P1315 in the future

Fix new codes early before secondary damage or catalyst stress
Keep connectors clean and secure; address rodent or water intrusion in harnesses
Use the correct fluids/parts for your vehicle and service intervals
Avoid ignoring pending codes after battery work or repairs

When to see a mechanic

Schedule diagnosis if the check engine light is on, drivability is worse, or you notice new noises, smells, or warning lamps. For safety-related (SRS/ABS) or overheating symptoms, prioritize a qualified shop immediately.

Common mistakes when diagnosing P1315

Replacing sensors/modules without verifying wiring and reference voltages
Ignoring related codes that identify the real root cause
Clearing codes without a verification drive cycle

Common vehicles & notes for P1315

Volkswagen / BMW models (common examples—verify for your vehicle)
Mercedes-Benz / Audi applications vary by engine and model year
Many other makes—this is a standardized OBD-II definition: Persistent Misfire

P1315 is reported across many platforms including Volkswagen, BMW, Mercedes-Benz, Audi. Always use VIN-specific service information for testing limits and calibration steps.

Frequently asked questions

What does P1315 mean?

P1315 indicates a fault involving Persistent Misfire, based on what the control module detected during self-tests or live monitoring.

Is it safe to drive with P1315?

If the vehicle runs normally and no warning lights are flashing, short trips may be reasonable—but avoid ignoring symptoms like misfire, overheating, ABS/SRS warnings, or major loss of power.

How much does it cost to fix P1315?

Typical repairs often fall in the ranges shown on this page, but final cost depends on labor rate, parts quality, and whether the issue is wiring vs. a major component.

What is the most common cause of P1315?

Most shops start with wiring/connectors and the directly monitored component for “Persistent Misfire,” then expand testing if the fault returns.

Will P1315 clear itself?

It may become intermittent, but if the underlying fault remains, the code will usually return—especially after a drive cycle.

Can a weak battery cause P1315?

Low system voltage can cause odd sensor/module behavior, but you should still validate the actual DTC and perform normal circuit/component tests.