The ICP sensor is supplied a 5 V reference signal at Pin 2 through valve cover gasket Pin B from ECM Pin
X1–14. The ICP sensor is supplied a signal ground at Pin 1 through valve cover gasket Pin C from ECM Pin
X1–6. The ECM monitors the ICP signal from sensor Pin 3 through valve cover gasket Pin A to ECM Pin X1–20.
Fault Detection / Management
The ECM continuously monitors the signal of the ICP sensor to determine if the signal is within an expected
range. If the ECM detects a voltage greater or less than expected, the ECM will set a DTC, illuminate the
amber ENGINE lamp, ignore the ICP sensor signal, and use a preset value based on engine operating conditions.
ICP Diagnostic Trouble Codes (DTCs)
DTCs are read using the EST or by counting the flashes from the amber and red ENGINE lamps.
DTC 124
ICP signal out-of-range low
• DTC 124 is set by the ECM if signal voltage is less than 0.039 V for more than 0.1 second.
• DTC 124 can be set due to an open or short to ground on the signal circuit, a failed ICP sensor or an open VREF circuit or VREF short to ground.
• When DTC 124 is active the amber ENGINE lamp is illuminated.
DTC 125
ICP signal out-of-range high
• DTC 125 is set by the ECM if the signal voltage is greater than 4.9 V for more than 0.1 second.
• DTC 125 can be set due to a signal circuit shorted to VREF or B+, or a failed ICP sensor.
• When DTC 125 is active the amber ENGINE lamp is illuminated.
DTC 332
ICP above specification with engine not running
• DTC 332 is set by the ECM, if the voltage signal from the ICP sensor is greater than expected with the key-on engine-off. If the ECM sets DTC 332, the ECM will ignore the ICP signal and operate the IPR with fixed values based on engine operating conditions.
• DTC 332 can be caused by an open signal ground, VREF shorted to voltage source greater than 5.5 V, a biased circuit, a failed ICP sensor, or a momentary loss of either the CMP or CKP signal.
• When DTC 332 is active the amber ENGINE lamp is illuminated.
Tools
• EST with MasterDiagnostics® software
• EZ-Tech® interface cable
• Digital Multimeter (DMM)
• 3-Banana Plug Harness
• 500 Ohm Resistor Harness
• VC Gasket Breakout Harness
• UVC Pressure Breakout Harness
• Breakout Box
• Terminal Test Adapter Kit
