1994 PCED OBDI-A
SECTION 18A: Diesel Diagnosis — 7.3L DI Engine
Z: Injection Control Pressure (ICP) Sensor
Introduction
  Z: Pinpoint Tests  





Signal Functions

The ICP (injection control pressure) sensor is a variable capacitance sensor that, when supplied with a 5 volt reference signal from the PCM, produces a linear analog voltage signal that indicates pressure.

The ICP (injection control sensor) sensor's primary function is to provide a feedback signal to indicate rail pressure so that the PCM can command the correct injector timing and pulse width and the correct injection control pressure for proper fuel delivery at all speed and load conditions.

Detection/Management

If the PCM detects a malfunctioning ICP sensor the CHECK ENGINE light is illuminated and the PCM will go to open loop control of injection control pressure. (Operate from an estimated ICP pressure.)





Note

After removing connector, check for damaged pins, corrosion, loose terminals, etc.



Connector Checks to Ground (B-)
(Check with sensor connector disconnected and ignition key off, all accessories off)
Test PointsSpec.ActualComments
A to Grd<5 ohms Resistance to ground check with key off. If greater than 5 ohms the harness is open
B to Grd>5 ohms Resistance less than 5 ohms indicates a short to ground
C to Grd>5 ohms Resistance less than 5 ohms indicates a short to ground



Connector Voltage Checks
(Check with sensor connector disconnected and ignition key on)
Test PointsSpec.ActualComments
A to Grd0-.25 volts If greater than .25 volts signal wire is shorted to VREF or battery
B to Grd5.0 ± .5 volt VREF check with key on
C to Grd<.25 volts Signal; if greater than .25 volts signal wire is shorted to VREF or battery



Harness Resistance Checks
(Check with breakout box installed on engine harness only)
Test PointsSpec.ActualComments
No. 91 to A<5 ohms Resistance from sensor connector to 104 pin connector
No. 87 to C<5 ohms Resistance from sensor connector to 104 pin connector
No. 90 to B<5 ohms Resistance from sensor connector to 104 pin connector

DTC Descriptions

153 = Signal voltage was less than 0.39 volts for more than .10 seconds.

154 = Signal voltage was greater than 4.90 volts for more than .10 seconds.

819 = Signal voltage was greater than 1.625 volts with key on/engine off.





 

 

  Z: Pinpoint Tests