Circuit Description

ECM determines ignition timing and outputs a ignition signal (IGT) to ignitor. Primary circuit is turned off when ECM delivers a signal to ignitor on IGT wire, causing ignition coil to fire spark plug. After delivering a command to turn off primary circuit, ECM monitors IGF circuit to ensure primary switching occurred. DTC P1300 is set when there is no IGF signal to ECM for 4 consecutive IGT1 signals during engine operation. DTC P1310 is set when there is no IGF signal to ECM for 4 consecutive IGT2 signals during engine operation. Possible causes are:

• IGF, IGT1 or IGT2 circuit from ignitor to ECM is open or shorted.
• Defective ignitor.
• Defective ECM.