The function diagram for the ICP sensor includes the following:
• ICP sensor
• Electronic Control Module (ECM)
• Injector Drive Module (IDM)
• Fuel injector
• Injection Pressure Regulator (IPR)
• ENGINE lamp (amber)
Function
The ICP sensor is a Micro Strain Gauge (MSG) sensor. The ICP sensor is under the valve cover, forward of the No. 6 fuel injector in the high-pressure oil rail. The engine harness connection on the valve cover gasket for the ICP sensor is left of the No. 6 injector connector. The ECM supplies a 5 V reference signal which the ICP sensor uses to produce a linear analog voltage that indicates pressure.
The ICP sensor provides a feedback signal to the ECM indicating injection control pressure. The ECM monitors ICP as the engine is operating to modulate the IPR. This is a closed loop function which means the ECM continuously monitors and adjusts for ideal ICP determined by conditions such as load, speed, and temperature.
The ECM monitors the ICP signal to determine if the performance of the hydraulic system is satisfactory. During engine operation, if the ECM recognizes that the ICP signal is greater or less than the value that the IPR is trying to achieve the ECM will set a DTC and illuminate the amber ENGINE lamp.
The ICP signal from the ECM is one of the signals the IDM uses to command the correct injector timing.
