Error code P1320 on Nissan Sunny FB15: complete analysis of the problem

Nissan Sunny FB15 with motor HR15DE — a reliable and economical car, but even it is not immune to errors in electronic systems. One of the most common problems that owners face is DTC P1320 ("Ignition Signal Primary"). This error is related to the ignition system and can manifest itself in different ways: from engine twitching to complete loss of power.

In this article we will look in detail at what it means P1320 on Sunny FB15, which components may be to blame, how to correctly diagnose the problem and what steps to take to fix it. We will pay special attention unique nuances specifically for this engine and model, which are often missed in general guides. If you see this code on your dashboard or scanner, don’t panic: in 80% of cases, the problem is solved without major repairs.

What does error P1320 mean on Nissan Sunny FB15?

Code P1320 in the diagnostic system Nissan stands for "Ignition Signal Primary" — error in the primary ignition signal. In context Sunny FB15 with engine HR15DE this means that ECU (electronic control unit) has detected an inconsistency or lack of signal from one or more ignition system components. It is important to understand: this code does not directly indicate a faulty element, but only signals a problem in the circuit.

In practice P1320 may be accompanied by the following symptoms:

• 🔥 Misfires (engine “troits”) at idle or under load;
• ⚡ Power Loss, especially during sudden acceleration;
• 🚗 Unstable work engine (speeds float);
• 🛑 Check Engine lights up and doesn't go out.

Unlike other errors (eg. P0300 - random misfires) P1320 more specifically: it points to a problem in primary circuit ignition system, that is, until a spark is formed. It could be:

• 🔌 Malfunction ignition coils;
• 📉 Problems with wiring or connectors;
• 🛠️ Problems with ECU or its firmware;
• 🔋 Low voltage in the on-board network.

Reasons for P1320 on Sunny FB15

On Nissan Sunny FB15 with motor HR15DE error P1320 most often associated with the design features of the ignition system. Unlike older models, they use custom ignition coils (one for each cylinder), which increases the number of potential failure points. Let's look at the main reasons:

1. Malfunction of ignition coils

Coils on FB15 - one of the most vulnerable places. Over time they may:

• 🔥 Overheat due to poor contact or cracks in the housing;
• 💧 Shorten when exposed to moisture (for example, after washing the engine);
• 🛠️ wear out naturally (resource ~100–150 thousand km).

2. Problems with wiring or connectors

Oxidation of contacts, breaks or short circuits in wiring harnesses are a common cause P1320. Particularly vulnerable:

• 🔌 Ignition coil connector (often oxidized or poorly fixed);
• 📡 Wires from the coils to the ECU (can rub against other elements under the hood);
• 🔋 Engine ground wire (corroded or poor contact).

3. Malfunction of the ECU or its firmware

Less often, but there are cases when an error P1320 arises due to:

• 🖥️ "Glitches" firmware ECU (especially after unsuccessful chip tuning);
• 🔌 Bad contact in the connectors of the control unit;
• 💥 ECU damage from power surges.

4. Other possible reasons

Sometimes P1320 may be a false positive due to:

• 🔋 Discharged battery or faulty generator;
• 🛠️ Poor quality fuel (detonation);
• 🔥 Engine overheating (affects sensor operation).

Why does P1320 often appear after an engine wash?

After washing, moisture can penetrate into the ignition coil connectors or cracks in high-voltage wires (if any). This results in a short circuit or current leakage, which the ECU perceives as a primary circuit failure. After washing, it is recommended to blow out the area of the coils and wires with compressed air, and also treat the contacts WD-40 or special lubricant for electrical contacts.

How to diagnose P1320 on a Nissan Sunny FB15?

Diagnostics P1320 requires a systematic approach. Start with the simplest checks and gradually move on to more complex ones. Important: before starting diagnostics reset the error scanner or disconnecting the battery (for 10–15 minutes). If the code appears again, the problem is confirmed.

Step 1: Visual inspection

Open the hood and inspect:

• 🔍 Ignition coils: are there any cracks, melting or traces of moisture;
• 🔌 Connectors: do they fit tightly, is there any oxidation;
• 📡 Wires: are they frayed or touching metal parts?

Step 2: Checking the Ignition Coils

To check the coils for Sunny FB15 You can use a multimeter:

1. Remove the connector from the coil.
2. Measure the resistance between the terminals 1 and 2 (primary winding): must be 0.5–1.0 Ohm.
3. Measure the resistance between the high voltage terminal and the terminal 2 (secondary winding): must be 5–10 kOhm.
4. If the values are outside the limits, the coil is faulty.

Step 3: Check Wiring

Use the multimeter in "dialing" mode:

• 🔌 Ring the wires from the coils to the ECU for a break;
• 🔋 Check the voltage at the coil connector with the ignition on (should be 12 V between + and mass);
• 📉 Make sure there is no short circuit to ground.

Step 4: ECU Diagnosis

If the coils and wiring are ok, but the error remains:

• 🖥️ Check the voltage at the ECU connector (should be stable 12 V);
• 🔧 Inspect the unit for signs of corrosion or damage;
• 📡 Try resetting the ECU adaptations via a diagnostic scanner (for example, Nissan Consult or Launch X431).

Reset the error and check if it appears again | Inspect the ignition coils for cracks and moisture | Check the resistance of the coils with a multimeter | Test the wiring from the coils to the ECU | Measure the voltage at the coil connector (12 V)

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Step 5: Check additional systems

If the diagnostics are unsuccessful, check:

• 🔋 Battery and generator: voltage should be 13.8–14.4 V at idle;
• 🛢️ Fuel quality: try filling with gasoline with a different octane number;
• 🔥 Knock sensor: its malfunction can indirectly affect the ignition.

How to Fix Error P1320: Step-by-Step Instructions

Remedy P1320 depends on the cause found. Below are step-by-step instructions for the most common cases.

1. Replacing a faulty ignition coil

If the diagnostics showed a coil malfunction:

1. Disconnect the negative terminal of the battery.
2. Remove the connector from the faulty coil.
3. Unscrew the coil mounting bolt (usually 10 mm).
4. Remove the coil and install a new one (we recommend the original Nissan 22448-JK00A or equivalent NGK/Denso).
5. Connect the battery connector and terminal.
6. Reset the error using the scanner.

2. Repair of wiring or connectors

If the problem is in the contacts:

• 🔧 Clean oxidized connectors WD-40 or special contact liquid;
• 🔌 Replace damaged wires (use heat shrink tube for insulation);
• 📡 Secure the wire harnesses so that they do not rub against the metal.

3. Reset ECU adaptations

If the error is related to ECU glitches:

1. Connect a diagnostic scanner (for example, Launch CReader).
2. Go to menu "Resetting adaptations" or "Throttle learning".
3. Perform a reset and reboot the ECU (disconnect the battery for 10 minutes).

4. Checking power and mass

Low voltage or bad ground may cause P1320:

• 🔋 Check the battery voltage (should be 12.6 V with the engine off);
• 🔌 Clean the battery terminals and the ground wire on the body;
• 📉 Make sure that the generator produces 13.8–14.4 V at idle.

Common mistakes when repairing P1320

Many owners Sunny FB15 make typical mistakes that lead to reoccurrence P1320 or new problems. That's what can't do:

1. Ignore code after reset

If you simply reset the error with a scanner or disconnecting the battery, but did not eliminate the cause, it will return. P1320 always has a specific reason, and it needs to be found.

2. Change coils “at random”

Some owners change all the coils in a row, hoping for a miracle. It's expensive and ineffective. First diagnose each coil with a multimeter or the permutation method.

3. Use non-original coils

Cheap analogues (for example, Chinese “no-name”) often fail after 10–20 thousand km. It's better to pay more for the original (Nissan 22448-JK00A) or proven brands (NGK, Denso, Bosch).

4. Do not check engine weight

A bad ground can simulate a bad coil. Always clean the ground wire from corrosion and check its attachment to the body.

5. Carry out repairs without diagnostics

Without a scanner and multimeter, you're guessing. Minimum diagnostic kit P1320:

• 🔧 Multimeter (from 200 rub.);
• 🖥️ Diagnostic scanner (from 1500 rub., for example, ELM327);
• 🔍 Flashlight for inspecting connectors.

Cost of repairs and selection of spare parts

Repair price P1320 on Nissan Sunny FB15 depends on the reason and the selected spare parts. Below are the estimated prices (for 2026):

Component	Original (price, rub.)	Analogue (price, rub.)	Cost of work (rub.)
Ignition coil	3 500–4 200 (Nissan 22448-JK00A)	1 800–2 500 (NGK, Denso)	500–800 (replacement of one)
Set of coils (4 pcs.)	14 000–16 000	7 000–10 000	1 500–2 000
Diagnostics with a scanner	—	—	500–1 500
Cleaning/repairing wiring	—	—	1 000–2 500
Reset ECU adaptations	—	—	300–800

Saving tips:

• 💰 If one coil is faulty, change only it (not necessarily a set);
• 🔧 You can clean connectors and bulk wires yourself;
• 📡 For diagnostics, buy an inexpensive scanner ELM327 (from 500 rub.) and program Torque Pro.

Where to buy spare parts?

Recommended verified suppliers:

• 🛒 Original: Nissan dealers, Exist.ru, Autodoc;
• 🛒 Analogues: NGK (coils U5057), Denso (coils 550-0109), Bosch;
• 🛒 Used: only if the seller guarantees performance (risky).

Prevention of error P1320 on Nissan Sunny FB15

To avoid reappearance P1320, follow these guidelines:

1. Regular inspection of the ignition system

Every 20–30 thousand km check:

• 🔍 Condition of the coils (are there any cracks, melts);
• 🔌 Density of connectors (they should not dangle);
• 💧 Lack of moisture in the engine compartment.

2. Use quality fuel

Bad gasoline can cause detonation, which increases the load on the coils. Refuel at trusted gas stations (for example, Lukoil, Gazpromneft, Rosneft) and avoid gasoline with an octane rating lower 92.

3. Monitor your battery and alternator

Low voltage in the on-board network is a common cause of false errors. Check:

• 🔋 Battery voltage (must be 12.6 V with the engine off);
• 🔌 Condition of terminals (cleanliness, tightness of fastening);
• 📉 Generator voltage (13.8–14.4 V at idle).

4. Avoid pressure washing the engine

Moisture entering the coil connectors may cause P1320. If you wash the engine:

• 💦 Cover the coils and connectors with polyethylene;
• 🌬️ After washing, blow with compressed air;
• 🔌 Process your contacts WD-40 or Liqui Moly Electronic-Spray.

5. Reset ECU adaptations regularly

After replacing the coils or battery, reset the adaptations through the scanner. This will help the ECU “retrain” to the new parameters.

FAQ: Frequently asked questions about P1320 on Nissan Sunny FB15

Is it possible to drive with error code P1320?

Short-term - possible, but not recommended. The error indicates problems with the ignition, which can lead to:

• 🔥 Increased fuel consumption;
• 🛠️ Overheating of the catalyst;
• 💥 Loss of power and jerking.

If the engine is unstable, it is better not to take risks and fix the problem.

How to reset P1320 without a scanner?

You can reset the error by disconnecting the negative battery terminal at 10–15 minutes. However, this will not eliminate the cause! If the code appears again, diagnostics are required.

Which ignition coils are best installed on the Sunny FB15?

Recommended options:

• 🥇 Original: Nissan 22448-JK00A (the most reliable, but expensive);
• 🥈 NGK: U5057 (good price/quality ratio);
• 🥉 Denso: 550-0109 (reliable, but may require ECU adaptation).

Avoid cheap Chinese analogues - they often fail after 10-20 thousand km.

Can P1320 be caused by bad gas?

Yes, but indirectly. Bad fuel can cause detonation, which increases the load on the ignition coils. If they are already worn out, this may cause an error. In this case:

1. Drain the bad gasoline;
2. Refuel with quality fuel;
3. Check the coils for spark.

What should I do if the error remains after replacing the coils?

Possible reasons:

• 🔌 Unconnected or oxidized connector;
• 🖥️ Unreset ECU adaptations;
• 💥 The problem is in the wiring or the ECU itself.

Check:

1. Connector density;
2. Coil voltage (12 V);
3. Resistance of new coils (must match the original).