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DTC codes / Toyota codes / P1325

P1325 · ToyotaIgniter Circuit Malfunction No 6

P1325 on Toyota vehicles means the engine control module (ECM) has detected a fault in the ignition coil circuit for cylinder number 6, specifically the igniter signal path. The ECM monitors the ignition coil's built-in igniter and expects a confirmation pulse each time it commands a spark; when that feedback is missing or out of range, it stores this code and may disable fuel delivery to that cylinder.

SystemPowertrain
Code typeToyota specific
SeverityMedium
Fix difficultyIntermediate
AreaIgnition system and misfire

Symptoms you may notice

  • Check engine light illuminated, often with no other noticeable symptoms at first
  • Rough idle or a noticeable vibration because cylinder 6 is misfiring
  • Loss of power and sluggish acceleration, especially under load
  • Shaking or hesitation during acceleration that may feel like a stumble
  • Worse fuel economy than normal due to incomplete combustion
  • In some cases, the engine may enter limp mode or flash the check engine light if the misfire is severe

Common causes, most likely first

  1. Faulty ignition coil with integrated igniter on cylinder 6
  2. Damaged or corroded electrical connector at the cylinder 6 ignition coil
  3. Open or shorted wire in the igniter signal circuit between the ECM and coil
  4. Failed spark plug or excessive spark plug gap causing the coil to overwork
  5. Poor engine ground connection affecting the ignition system
  6. Rarely, a failed driver circuit inside the ECM

How to diagnose and fix it

  1. Scan all stored and pending codes with an OBD-II scanner to confirm P1325 is the only ignition-related code
  2. Inspect the cylinder 6 ignition coil connector and wiring for corrosion, loose pins, or chafed insulation
  3. Swap the cylinder 6 ignition coil with a known-good coil from another cylinder and see if the misfire moves
  4. Check the spark plug condition and gap, replacing if worn or fouled
  5. Measure resistance of the igniter signal wire from the coil connector to the ECM to rule out an open circuit
  6. Verify engine ground straps are clean and tight, especially the one near the ignition coils
  7. If all external checks pass, test the ECM driver circuit with an oscilloscope or substitute a known-good ECM

Igniter feedback faults that fool many technicians

  • A coil that sparks fine on a bench test can still set P1325 because the igniter feedback signal inside the coil has failed, so the ECM cannot confirm ignition occurred.
  • Corroded pins in the coil connector are a frequent cause on older Toyota engines, and simply unplugging and reconnecting the connector can temporarily clear the fault and mislead you.
  • P1325 is often accompanied by a misfire code for the same cylinder, but the misfire code may be the only one stored if the ECM does not enable the igniter monitor under certain conditions.
  • A weak battery or charging system fault can cause erratic igniter signals and set this code without any coil being defective.
  • Do not overlook the spark plug tube seals; oil leaking into the spark plug well can short the coil and trigger P1325 without any visible wire damage.

Can I keep driving with P1325?

You can drive cautiously to a repair shop, but avoid heavy acceleration and prolonged driving because unburned fuel from the misfiring cylinder can overheat and damage the catalytic converter. If the check engine light is flashing, stop driving and have the vehicle towed.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for Toyota vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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