Ignition Mode

The scan tool displays Bypass/IC. The bypass indicates the Ignition Control (IC) module is keeping the spark advance at a fixed 10 degrees BTDC, bypass mode. The ignition control module determines the correct operating mode based on the level of the voltage that the PCM sends to the ignition control module on the bypass circuit. If the PCM does not turn ON the 5 volts, or if the ignition control module does not receive the voltage, the module will control spark timing. The ignition control (IC) indicates that the PCM has signaled the ignition module that the PCM is going to control the spark advance, IC mode. The ignition control module determines the correct operating mode based on the level of voltage that the PCM sends to the ignition control module on the bypass circuit. The PCM provides 5 volts to the ignition control module bypass circuit if the PCM is going to control spark timing, IC mode. If the PCM does not turn ON the 5 volts, or if the ignition control module does not receive the voltage, the module will control spark timing, bypass mode.