883608T55 Mercruiser GEAR HOUSING ASSEMBLY, Basic

Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
100-3 Engine Oil Pressure Sensor : Voltage Above Normal The ECM detects signal voltage that is above normal.
The ECM has been powered for at least two seconds. The code is logged.
The value of the parameter is set to a gauge pressure of 500 kPa (75 psi).
100-4 Engine Oil Pressure Sensor : Voltage Below Normal The ECM detects signal voltage that is below normal.
The ECM has been powered for two seconds.
100-10 Engine Oil Pressure Sensor : Abnormal Rate of Change The ECM detects signal voltage that is not changing at a normal rate for thirty seconds. Engine speed must be above 600 rpm.
The ECM has been powered for two seconds.
274-3 Atmospheric Pressure Sensor : Voltage Above Normal The ECM detects signal voltage that is above normal.
The ECM has been powered for at least two seconds. The code is logged.
The value of the parameter is set to 100 kPa (14.5 psi).
274-4 Atmospheric Pressure Sensor : Voltage Below Normal The ECM detects signal voltage that is below normal.
The ECM has been powered for two seconds.
1785-3 Intake Manifold Pressure Sensor : Voltage Above Normal The ECM detects signal voltage that is above normal.
The ECM has been powered for at least two seconds. The code is logged.
The value of the parameter is set to 100 kPa (14.5 psi).
1785-4 Intake Manifold Pressure Sensor : Voltage Below Normal The ECM detects signal voltage that is below normal.
The ECM has been powered for two seconds.
1785-10 Intake Manifold Pressure Sensor : Abnormal Rate of Change The ECM detects signal voltage that is not changing at a normal rate for thirty seconds. Engine speed must be above 1000 rpm.
The ECM has been powered for two seconds.
1797-3 Fuel Rail Pressure Sensor : Voltage Above Normal The ECM detects signal voltage that is above normal.
The ECM has been powered for at least two seconds. The code is logged.
The value of the parameter is set to a default value of 100 MPa (14504 psi).
1797-4 Fuel Rail Pressure Sensor : Voltage Below Normal The ECM detects signal voltage that is below normal.
The ECM has been powered for two seconds.
1797-7 Fuel Rail Pressure Sensor : Not Responding Properly The ECM detects signal voltage that is not changing at a normal rate for thirty seconds. Engine speed must be above 1000 rpm.
The ECM has been powered for two seconds. System OperationUse this procedure to troubleshoot any suspect problems with the following sensors:
Atmospheric pressure sensor
Engine oil pressure sensor
Fuel pressure sensor
Fuel rail pressure sensor
Turbocharger inlet pressure sensor
Intake manifold pressure sensorNote: Refer to Troubleshooting, "Fuel System Pressure - Test" for additional information concerning fuel pressure.The supply voltage is routed to terminal A of each sensor connector. The sensor return is routed to terminal B of each sensor connector. The sensor signal is routed to terminal C of each sensor connector. The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.The ECM performs an automatic calibration of these sensors whenever the ECM is powered and the engine is off for at least five seconds. During an automatic calibration, the ECM calibrates pressure sensors to the value of the atmospheric pressure sensor and against an acceptable offset pressure range.The ECM continuously outputs a pull-up voltage on the input terminal from an analog sensor. The ECM uses this pull-up voltage in order to detect an open or a short in the signal circuit. When the ECM detects the presence of a voltage that is above the normal range of the sensor on the signal circuit, the ECM will generate an open circuit diagnostic code -3 for that sensor. When the ECM detects the absence of the pull-up voltage on the signal circuit, the ECM will generate a short circuit diagnostic code -4 for that sensor. The presence of pull-up voltage at the sensor connector indicates that the wires from the sensor connector to the ECM are not open or shorted to ground.
Illustration 1 g01682858
Typical schematic
Illustration 2 g01683118
P1 ECM connector
(P1-2) Sensor supply
(P1-3) Sensor return
(P1-15) Turbocharger inlet pressure sensor
Illustration 3 g01683135
P2 ECM connector
(P2-15) Intake manifold pressure sensor
(P2-17) Sensor return
(P2-28) Engine oil pressure sensor
(P2-40) Fuel pressure sensor
(P2-85) Fuel rail pressure sensor
(P2-57) Atmospheric pressure sensor
(P2-72) Sensor supply
(P2-54) Sensor return
(P2-80) Sensor supply
Illustration 4 g01159881
Sensor connector
(A) 5 V sensor supply
(B) Sensor return
(C) Signal Test Step 1. CHECK FOR "ACTIVE" OR "LOGGED" DIAGNOSTIC CODES
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position.
Monitor the diagnostic codes on Cat ET. Check and record any diagnostic codes. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Determine if a diagnostic code has occurred several times. Note: A diagnostic code that is logged several times is an indication of an intermittent problem. Most intermittent problems are the result of a bad connection between a socket and a pin in a connector or a bad connection between a wire and a terminal. The problem may be caused by moisture, corrosion, or wear.
Determine if the problem is active and related to one of the following diagnostic codes:
-3
-4
-10Expected Result:A diagnostic code is not active.Results:
OK - A diagnostic code is not active.Repair: The problem may be intermittent. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - A -10 diagnostic code is active.Repair: A -10 diagnostic code indicates an open in the voltage supply to a sensor. If the code is only present for one sensor, the open will be between the sensor connector and a splice. If the open is for two or more sensors the open will be before the splice for the voltage supply to those sensors. Repair the open in the wiring or connectors. Refer to the electrical schematic for the locations of splices in the harness.STOP
Not OK - A -3 code or a -4 code is active. Proceed to Test Step 2.Test Step 2. CHECK THE 5 VOLT SUPPLY VOLTAGE AT THE SENSOR CONNECTOR
Do not disconnect the suspect connector.
Connect a voltmeter between