Circuit DescriptionThe injector solenoid valves control fueling quantity and injection timing. The electronic control module (ECM) energizes the solenoid by closing a high-side and a low-side switch. There are two high-side switches and four low-side switches inside the ECM. The injectors for cylinder numbers 1 and 2 (front bank) share a single high-side switch that connects the injector circuit to the source of high voltage inside the ECM. Likewise, the injectors for cylinder numbers 3 and 4 (rear bank) also share a single high-side switch. Each injector circuit has a dedicated low-side switch that completes the circuit path to ground...

Circuit DescriptionThe injector solenoid valves control fueling quantity and injection timing. The electronic control module (ECM) energizes the solenoid by closing a high-side and a low-side switch. There are two high-side switches and four low-side switches inside the ECM. The injectors for cylinder numbers 1 and 2 (front bank) share a single high-side switch that connects the injector circuit to the source of high voltage inside the ECM. Likewise, the injectors for cylinder numbers 3 and 4 (rear bank) also share a single high-side switch. Each injector circuit has a dedicated low-side switch that completes the circuit path to ground...

Circuit DescriptionThe engine coolant temperature sensor is used by the electronic control module (ECM) to monitor the engine coolant temperature. The ECM monitors the voltage on the signal pin and converts this to a temperature value. The engine coolant temperature value is used by the ECM for the engine protection system and engine emission control. Component LocationThe engine coolant temperature sensor is located on the thermostat housing. Conditions for Running the DiagnosticsThe engine must be turned off for period of 8 hours before this diagnostic will run. This diagnostic runs when the keyswitch is turned to the ON position after...

Circuit DescriptionThe electronic control module (ECM) Idle Shutdown feature has an optional parameter for a shutdown accessory relay. When this parameter is set to “Installed”, the ECM sends a signal to energize the relay and turn off vehicle accessories during idle shutdown events. The idle shutdown relay return circuit varies by original equipment manufacturer (OEM). The return circuit can be returned to the ECM through the ECM Return (General) or connected directly to ground. Refer to the OEM service manual to determine grounding configuration. Component LocationThis idle shutdown relay location varies by OEM. Refer to the OEM service manual to...

Circuit DescriptionThe engine control module (ECM) uses the EGR differential pressure sensor reading to determine how much exhaust gas is flowing through the EGR connection tube to the intake manifold. The EGR differential pressure sensor measures the pressure drop across the EGR differential pressure orifice using two exhaust ports. The sensor outputs a voltage, which represents the pressure difference between the two ports, and the ECM correlates that voltage to an EGR flow rate. This information is used to control the EGR valve for correct emission levels. The ECM provides a 5 volt supply to the EGR differential pressure sensor...