P1325 – Ignition control – cylinder No. 6 – circuit malfunction (Toyota)

By Reinier (Contact Me)
Last Updated 2022-02-07
Automobile Repair Shop Owner

Manufacturer Specific Definitions for P1325

Table of Contents

1. What Does Code P1325 Mean?
2. Where is the P1325 sensor located?
3. What are the common causes of code P1325?
4. What are the symptoms of code P1325?
5. Get Help with P1325

What Does Code P1325 Mean?

OBD II fault code P1325 is a manufacturer-specific trouble code that is defined by carmaker Toyota as, “Ignition control – cylinder No. 6 – circuit malfunction”, and is set when the PCM (Powertrain Control Module) detects a failure or malfunction in the primary circuits that control the igniter on cylinder #6.

NOTE: In Toyota-speak, an “igniter” is the ignition coil that connects the sparkplug to the larger ignition system. These are also knows as COPs, or Coil Over Plug units. In common parlance, these ignition coils are also known as “pencil coils” after their passing resemblance to pencils.

All modern Toyota gasoline engines use a so-called DIS (Direct Ignition System) to deliver ignition sparks to the cylinders. In practice, what this means is that each cylinder is equipped with its own ignition coil, unlike many other vehicle makes and models that use integrated coil packs that deliver ignition sparks to multiple cylinders.

On Toyota applications, the crankshaft position sensor generates electrical signals that the PCM uses as triggers to calculate appropriate ignition timing strategies. As a practical matter, the PCM can delay or advance the delivery of primary ignition triggers to the ignition coils based on the engine speed, engine load, and other operational parameters.

Nonetheless, when the PCM receives a trigger signal from the crankshaft position sensor, it relays the signal to the primary windings in the ignition coil, which then creates a magnetic field during a period known as the ramp-up time. Based on the ignition timing setting for any given engine speed, the PCM interrupts the primary signal to the coil at an appropriate moment, which causes the magnetic field in the coil’s primary windings to collapse.

The collapse of the field then creates a stronger magnetic field in the ignition coil’s secondary windings, which is the mechanism that generates the actual ignition spark. If both the ignition coil and the sparkplug are fully functional, the ignition spark will be intense enough to ignite the air/fuel mixture in the cylinder at exactly the right moment to produce a torque input.

However, to ensure a high degree of control over the ignition system, the PCM expects to see confirmation that an ignition spark had in fact been created and delivered. This confirmation is achieved by monitoring a dedicated feedback signal that occurs when the PCM turns off the current to the coil’s primary windings.

This process is known as “primary switching”, and when it does not occur for four consecutive ignition cycles, the PCM will recognize that it cannot control the ignition circuit for the affected cylinder effectively, and it will set code P1325 and illuminate a warning light as a result. In addition to setting the trouble code, the PCM will also disable the fuel injector on the affected cylinder to prevent uncombusted fuel from entering the catalytic converter(s), which if it happens, could cause the converter(s) to overheat to the point of melting.

Where is the P1325 sensor located?

This image shows an ignition coil (aka igniter) that is suitable for use on a Toyota Camry. Note that while the actual appearance of Toyota ignition coils varies somewhat between various models, the design of all Toyota igniters intended for use on Direct Ignition Systems follow this general pattern.

In terms of their location, all igniters used in Direct Ignition Systems are arranged in-line in the middle of the cylinder head, and are for the most part, secured to the valve cover(s) with a single retaining screw/bolt. Note though, that on some Toyota models, it may be necessary to remove a cosmetic engine cover to access the igniters. However, since code P1325 indicates a problem with the igniter on cylinder #6, be sure to consult reliable service information for the affected engine to identify cylinder #6 correctly on V-type engines.

WARNING: If replacing the affected igniter with an OEM, or OEM equivalent part does not resolve the problem, the best course of action to follow would be to seek professional assistance with diagnosis and repair of this code. A large part of diagnosing this code involves performing pinpoint tests directly on the PCM and several critically important connectors, which means that getting these procedures wrong could result in destroying the PCM and/or other control modules.

What are the common causes of code P1325?

The most common causes of code P1325 on Toyota applications are largely similar on all models, and typically include one or more of the following-

• Burnt, damaged, shorted, or corroded wiring and/or electrical connectors between the crankshaft position sensor and the PCM, and/or between the PCM and the affected igniter, but note that defective or failed crankshaft position sensors will typically affect all the cylinders, as opposed to affecting only one cylinder
• Defective, failed, or malfunctioning igniter on cylinder #6
• The use of a substandard aftermarket igniter on cylinder #6
• Defective, failed, or malfunctioning spark plug on cylinder #6
• Failed or defective PCM, but note that unlike most other trouble codes, PCM failure is the primary cause of many, if not most instances of code P1325 on Toyota applications

NOTE: Failed or defective fuel injectors, or mechanical issues that cause a loss of compression in the affected cylinder will not cause this code to set.

What are the symptoms of code P1325?

Typical symptoms of code P1325 are largely similar across all Toyota models, and typically include the following-

• Stored trouble code and an illuminated warning light
• In almost all instances of this code on Toyota applications, code P1325 will be accompanied by code P0306 – “Misfire Detected – Cylinder No. 6”, but note that code P0306 will be the result of code P1325 being present, as opposed to code P0306 being the cause of the misfire
• In cases where a PCM failure is involved, one or more UXXXX (Communications) codes will be present along with code P1325
• The engine will display a severe misfire
• The engine will display as severe loss of power
• Fuel consumption will increase significantly

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