Circuit Description

The DTC P0617 Starter Relay Control Circuit High Voltage diagnostic monitors the voltage signal that is sent from the ignition switch when starting the engine. When the engine is being cranked, battery voltage is applied to the powertrain control module (PCM). On a cold engine the PCM can increase the fuel injection volume and modify ignition timing when receiving the start signal. This signal passes through the park neutral position (PNP) switch or the clutch pedal position (CPP) switch. If this signal is not detected during engine cranking, the PCM will still allow the engine to start.