Ignition Mode

Scan Tool displays Bypass/IC. Bypass indicates the ignition control 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 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 doesn't receive it, the module will control spark timing. 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 doesn't receive it, the module will control of spark timing (Bypass mode).