P1320 critical

Ignition Signal Primary Circuit Fault (Nissan/Infiniti)

The P1320 code means the vehicle's onboard diagnostic system has detected: Ignition Signal Primary Circuit Fault (Nissan/Infiniti). This is a critical severity code.

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Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$75 - $400 (parts and labor)

Manufacturer-specific code. P1320 is a manufacturer-specific DTC, so its exact definition can differ by make, model, and year. Use the meaning above as a general guide, and always confirm it against your vehicle manufacturer's official service information (or a make-specific scan tool) before diagnosing or replacing parts.

What Are the Symptoms of P1320?

  • Check Engine Light on
  • Engine misfiring on one or more cylinders
  • Rough idle and vibration
  • Loss of power during acceleration
  • Poor fuel economy

What Causes P1320? (Most Likely First)

  • Failed ignition coil Very High
  • Worn or fouled spark plugs High
  • Damaged coil connector or wiring Moderate
  • Failed power transistor module Moderate
  • ECM ignition driver circuit fault Low

Can I Still Drive with P1320?

Short distances only. P1320 is rated critical severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.

Frequently Asked Questions

Can I drive with code P1320?

You can drive short distances. The engine will misfire, causing rough running and reduced power. Avoid heavy acceleration to prevent catalytic converter damage.

What causes P1320 on Nissan?

A failed ignition coil is the most common cause. Unlike many manufacturers that use specific cylinder codes, Nissan uses P1320 as a general ignition circuit code. Check all coils.

How do I find which coil is bad?

Swap coils one at a time between cylinders. Clear the codes and run the engine. The bad coil will cause a misfire wherever it is installed. On some Nissan models, Mode 4 data can identify the specific cylinder.

Mechanics Guide Step-by-step diagnosis

How Do You Diagnose P1320?

  1. Swap ignition coils between cylinders to identify the faulty coil

  2. Inspect and replace spark plugs if worn or fouled

  3. Check ignition coil connectors for corrosion or damage

  4. Measure ignition coil primary and secondary resistance

  5. Test the power transistor module if equipped

Which Vehicles Commonly Get P1320?

  • 2002-2016 Nissan Altima
  • 2003-2017 Nissan Maxima
  • 2004-2018 Nissan Pathfinder
  • 2005-2019 Infiniti G35/G37
  • 2006-2020 Nissan Frontier

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