P1305 Code failures by brands



Description of DTC code P1305

The engines that use the DIS (Direct Ignition) system do not use rotary distributors to deliver ignition spark to the cylinders. As an alternative, they rely on signals from engine sensors, for example, the CKP (Crankshaft Position Sensor) or CMP (Camshaft Position Sensor). The PCM can set the best ignition timing with this information at any given load and engine speed. Ignition timing accuracy and a significant reduction in high voltage losses are achieved with the igniter, extending the life of these components.

The igniter sends a primary ignition signal to the cylinders that are connected via an ignition coil. The PCM calculates the accurate time at which this primary ignition signal should be delivered. Once the igniter receives it, it transmits it to the primary winding of the coil for the appropriate cylinder. The igniter's power transistors interrupt the signal to create a high voltage in the secondary winding of the coil.

Although this is the voltage that produces the spark to ignite the air-fuel mixture, the PCM requires the voltage that produces the ignition for that cylinder, so the igniter provides an Ignition Feedback (IGF) signal after the primary signal has been interrupted. The PCM continuously monitors this signal for all cylinders. In case the IGF signal is not present or not adequate, the P1305 OBD2 diagnostic code will be set.

Symptoms of fault code P1305

  • Check Engine light ON.
  • Significant increase in fuel consumption.
  • The engine loses power.
  • The engine stops unexpectedly.
  • Unstable idle.
  • Other misfire-related error codes are set.

Causes of OBD2 P1305

Reasons for setting the P1305 OBDII fault code are as follows:

  • The connectors or wires in the cigarette lighter circuit may be damaged.
  • An ignition coil could be bad.
  • The cigarette lighter may be malfunctioning.

Possible solutions of the DTC code P1305

To troubleshoot the DTC P1305 OBD2, try this:

  • First, consult the TSB (Technical Service Bulletins). These contain useful information that will help you in your diagnosis.
  • Check the coil and spark plug connections for inconsistencies with the engine idling. Repair or replace any wires that require it.
  • Verify that the spark plugs and ignition coils meet the voltage requirements necessary for proper operation. If you find that one of these is bad, replace it.
  • Consult the service manual and connector table for IGT and IGF circuits for the faulty cylinder. Check that this circuit is not shorted or open. Also, check that it meets the proper resistance and continuity levels.
  • Activate the igniter and test the voltages of the wires between the ground and the connector on the PCM. If one of these values is below 4.5 V and 5.5 V, the igniter is bad. Replace it.

Codes related to P1305

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