Ignition Signal Primary Circuit Fault (Nissan/Infiniti)
What does P1320 mean?
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.
Common Symptoms
- Check Engine Light on
- Engine misfiring on one or more cylinders
- Rough idle and vibration
- Loss of power during acceleration
- Poor fuel economy
Probable Causes (Ranked by Likelihood)
- 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
Step-by-Step Diagnostic Procedure
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Swap ignition coils between cylinders to identify the faulty coil
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Inspect and replace spark plugs if worn or fouled
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Check ignition coil connectors for corrosion or damage
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Measure ignition coil primary and secondary resistance
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Test the power transistor module if equipped
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.