24748 1 Force GASKET, FUEL PUMP

Table 1
Diagnostic Codes Table
Description Conditions which Generate this Code System Response
106-3 Air Inlet Pressure Sensor : Voltage Above Normal The Electronic Control Module (ECM) has detected a frequency of less than 375 Hz for the sensor PWM signal. The code is logged.
The alarm output is activated.
The shutdown output is activated.
The engine is shut down.
106-4 Air Inlet Pressure Sensor : Voltage Below Normal The ECM has detected a voltage on the circuit that is less than 0.2 V for five seconds.
106-8 Air Inlet Pressure Sensor : Abnormal Frequency, Pulse Width, or Period The ECM has detected a frequency that is greater than 625 Hz for the sensor PWM signal.
or
The duty cycle is greater than 95 percent or the duty cycle is less than 5 percent for the sensor PWM signal.
109-3 Engine Coolant Outlet Pressure Sensor : Voltage Above Normal The ECM has detected a frequency of less than 375 Hz for the sensor PWM signal. The code is logged.
The alarm output is activated.
109-8 Engine Coolant Outlet Pressure Sensor : Abnormal Frequency, Pulse Width, or Period The ECM has detected a frequency that is greater than 625 Hz for the sensor PWM signal.
or
The duty cycle is greater than 95 percent or the duty cycle is less than 5 percent for the sensor PWM signal. The following PWM sensors are used by this engine:
Engine coolant pressure (outlet)
Intake manifold pressure
Illustration 1 g01423130
Components for the PWM sensors
(1) Analog pressure sensor
(2) Signal converter The PWM sensor circuit consists of an analog pressure sensor and a signal converter. The signal converter receives a 8.0 0.4 VDC regulated voltage from the ECM. The signal converter provides 5.0 0.25 VDC to the analog sensor. The analog pressure sensor provides an analog signal to the signal converter that represents the pressure that is being sampled. The signal converter converts the analog signal to a PWM signal and the converter then transmits the signal to the ECM.The signal converter generates a PWM signal that is in a specific range of duty cycle that is sent to the ECM. This range is directly related to the pressures that are sampled by the pressure sensor. As the pressure of the sensor fluctuates between the minimum and the maximum pressures, the duty cycle fluctuates on a scale that is directly related to the pressure. The sensor signal converter generates a frequency of 500 100 Hz for the PWM signal. If the frequency of the sensor PWM signal is out of the specification, a diagnostic code will be generated.Excessive pressure can generate electrical noise interference in the circuitry that is for the sensors. Although there is not a problem with the sensor, the following codes will be generated for the given pressures:If the actual intake manifold pressure (absolute pressure) is greater than approximately 446 kPa (65 psi), a 106-8 Air Inlet Pressure Sensor abnormal frequency, pulse width, or period will be generated.If the actual engine coolant pressure (absolute pressure) is greater than approximately 446 kPa (65 psi), a 109-8 Engine Coolant Outlet Pressure Sensor abnormal frequency, pulse width, or period will be generated.If a 106-8 or 109-8 diagnostic code is generated, measure the actual pressure with a pressure gauge before you troubleshoot the sensor. If the pressure is too high, repair the system in order to reduce the pressure. Measuring the pressure will avoid activation of false diagnostic codes.A -3 diagnostic code for the pressure sensors is probably caused by a short circuit to the +Battery in the harness or by an open circuit in a harness. The next likely cause is a sensor problem. The least likely cause is a problem with the ECM.
Illustration 2 g03086916
Schematic of the circuits for the PWM sensors
Test Step 1. Inspect the Electrical Connectors and the Wiring
Set the engine control to the OFF/RESET position. Remove the electrical power from the engine.
Illustration 3 g01771854
Locations of the PWM sensors (typical left front engine view)
(3) Engine coolant pressure sensor (outlet)
(4) Intake manifold pressure sensor
Illustration 4 g01771856
Locations of the connectors at the ECM junction box for the PWM sensors (typical left front engine view)
(5) J2/P2 ECM connectors
(6) J1/P1 ECM connectors
(7) Control harness connectors
Thoroughly inspect the connectors for sensors (3) and (4). Also, thoroughly inspect ECM connectors (5) and (6), and control harness connectors (7). Refer to Troubleshooting, "Electrical Connectors - Inspect" for details that are related to inspection of the electrical connectors.
Illustration 5 g01418762
Terminal locations at the J1/P1 ECM connectors that are for the PWM sensors
(P1-4) 8 V supply
(P1-5) Return
(P1-10) Intake manifold pressure
Illustration 6 g01771873
Terminal locations at the J2/P2 ECM connectors that are for the PWM sensors
(P2-68) Engine coolant pressure (outlet)
Illustration 7 g01771893
Terminal locations at the control harness connectors that are for the PWM sensors
(Terminal AH) 8 V supply for the intake manifold pressure sensor
(Terminal AJ) Return for the intake manifold pressure sensor
(Terminal AK) Intake manifold pressure
(Terminal AL) Shield for the intake manifold pressure sensor