The P1320 code is a manufacturer-specific powertrain code. Unlike a standard generic OBD-II code, its exact definition depends entirely on the vehicle application, typically relating to ignition signal faults.
This code identifies a detected electrical circuit condition or missing signal, not necessarily a failed ignition coil. Proper diagnosis requires verifying the exact factory definition and testing the relevant circuits.
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Key Takeaways
- The P1320 code is manufacturer-specific, indicating an ignition signal, igniter circuit, or ionization sensor fault depending on the vehicle.
- Possible causes include wiring faults, poor electrical connections, failed ignition coils, or a faulty igniter module.
- Symptoms typically include an illuminated Check Engine Light, engine misfires, stalling, or a no-start condition.
- Diagnosis requires confirming the exact factory definition and testing the specific ignition control and feedback circuits.
- Repairs depend on the confirmed fault and may involve wiring repair, ignition coil replacement, or igniter replacement.
P1320 Code Description and Implications
P1320 is a manufacturer-specific code. Its exact definition depends entirely on the vehicle application.
Some Nissan and Infiniti applications: The code indicates an “Ignition Signal” fault. The Engine Control Module (ECM) does not receive the primary ignition signal from the ignition coil or power transistor during cranking or running.
Toyota and Lexus applications: The code indicates an “Igniter Circuit Malfunction.” The ECM detects a fault in the ignition confirmation signal circuit from the igniter module.
Volvo and Saab applications: The code may relate to an ionization sensor circuit fault or specific misfire detection. Because definitions vary, verifying the exact factory service information is mandatory.
Common Causes of the P1320 Code
Several conditions can trigger this manufacturer-specific malfunction code. Identifying the exact cause requires electrical testing of the specific circuit.
- Wiring issues: Open or short circuits in the ignition control or feedback signal wires.
- Poor electrical connections: Corroded, loose, or contaminated connectors at the ignition coil, igniter, or ECM.
- Failed ignition components: A faulty ignition coil, power transistor, or igniter module failing to send the confirmation signal.
- Blown fuses supplying power to the ignition system.
- A faulty ECM or internal module driver issue (rare, usually only after circuit verification).
Symptoms Associated With P1320
Symptoms vary depending on the specific system design and the underlying fault condition.
- Illuminated Check Engine Light.
- Engine stalling immediately after starting or a complete no-start condition, especially on applications where fuel injectors are disabled without an ignition signal.
- Rough idle, engine misfires, or hesitation during acceleration.
- In some applications, the vehicle may enter a fail-safe or limp mode to protect the engine and catalytic converter.
Diagnosing the P1320 Trouble Code
Diagnosis must begin by confirming the exact factory definition and inspecting the physical system components.
- Verify the exact manufacturer definition and locate the wiring diagram for the specific ignition control and feedback circuits.
- Visually inspect the wiring harness and connectors at the ignition coils, power transistor, and ECM for damage, chafing, or corrosion.
- Check the relevant fuses and relays supplying power to the ignition system.
- Use a digital multimeter or oscilloscope to test the ignition control signal and the feedback circuit for proper switching and voltage levels.
- Swap ignition coils between cylinders if applicable to see if the fault follows the component or remains with the circuit.
Repairing the P1320 Issue
Repairs depend entirely on the confirmed root cause of the system malfunction.
- If wiring damage or an open/short circuit is found, repair or replace the affected harness sections and secure the routing.
- Clean or replace corroded connectors to restore proper electrical contact and circuit integrity.
- If the ignition coil, power transistor, or igniter fails electrical or functional testing, replace it using a component meeting the correct vehicle specification.
- If testing confirms the ECM is faulty and all external circuits are intact, follow the manufacturer procedure for module replacement.
Cost Considerations for P1320 Repairs
Cost depends on diagnostic time, component accessibility, required parts, programming requirements, and labor.
Replacing a single ignition coil or repairing a wire is generally less expensive than replacing an external igniter module or performing ECM diagnostics and replacement.
Prevention Strategies for Future Occurrences
While electrical and mechanical failures are not always preventable, some practices can reduce the risk of ignition system issues.
- Inspecting exposed wiring and connectors can help identify developing damage from heat exposure, chafing, or moisture intrusion.
- Keeping electrical connections clean and sealed helps prevent corrosion in harsh climates.
- Ensuring the ignition system is free from oil or coolant leaks that could degrade coil boots and connectors.
Troubleshooting Tips and Best Practices
Always consult the exact manufacturer service information for your vehicle’s wiring diagram and expected signal waveforms.
- Do not assume an ignition coil is faulty simply because the code points to the ignition signal; wiring damage and poor connections must be ruled out first.
- On applications where a missing ignition signal disables fuel injection, verifying the presence of the ignition signal is critical before condemning the fuel system.
- Verify technical service bulletins for your specific make and model, as some manufacturers issue updated wiring harnesses or revised ignition components for recurring signal faults.
More OBD-II Codes
| P1298 | P1299 | P1300 | P1305 |
| P1310 | P1315 | P1321 | P1322 |
| P1323 | P1324 | P1325 | P1330 |
| P0300 | P0301 | P0302 | P0313 |
| P0325 | P1336 | P1350 | P1351 |
| P1352 | P1380 | P1381 | P1390 |
Frequently Asked Questions
Is the P1320 code generic or manufacturer-specific?
No. P1320 is a manufacturer-specific code. Its exact definition varies by vehicle make, typically indicating an ignition signal or igniter circuit fault.
Can I drive my car with a P1320 code?
It depends on the application. On some vehicles, a missing ignition signal will disable the fuel injectors, causing a no-start condition or immediate stalling, making the vehicle undrivable.
Will a bad ignition coil cause a P1320 code?
Yes. On applications monitoring the primary ignition signal, a failed ignition coil or its internal power transistor will prevent the confirmation signal from reaching the ECM, triggering the code.
Can a wiring issue trigger the P1320 code?
Yes. An open circuit, short to ground, or high resistance in the ignition feedback signal wire between the ignition coil or igniter and the ECM will cause a signal fault.
Will a P1320 code cause an emissions test failure?
Yes. Any code that illuminates the Check Engine Light or indicates an active misfire or ignition system fault will cause an automatic failure during an OBD-II emissions inspection.
What Should You Do About the P1320 Code?
Confirm the exact factory definition for your specific vehicle application. Follow the applicable manufacturer diagnostic procedure to test the relevant ignition control circuits, feedback signals, and components.
Repair or replace the confirmed failed component or fix the identified wiring fault, then retest the system to ensure proper operation.
