33925-93J00 Suzuki CUSHION, ENGINE CONTROL UNIT

Table 1
Diagnostic Codes Table    
Code and Description    Conditions which Generate this Code    System Response    
94-3 Fuel Delivery Pressure Sensor voltage above normal     The Electronic Control Module (ECM) detects signal voltage that is above normal for 8seconds.
The ECM has been powered for at least 2 seconds.     The code is logged.
The value of the parameter is set to a gauge pressure of 500 kPa (75 psi).    
94-4 Fuel Delivery Pressure Sensor voltage below normal     The ECM detects signal voltage that is below normal for 8 seconds.
The ECM has been powered for 2seconds.    
100-3 Engine Oil Pressure Sensor voltage above normal     The ECM detects signal voltage that is above normal for 8 seconds.
The ECM has been powered for at least 2 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 for eight second.
The ECM has been powered for 2 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 30 seconds. Engine speed must be above 600 rpm.
The ECM has been powered for 2 seconds.    
274-3 Atmospheric Pressure Sensor voltage above normal     The ECM detects signal voltage that is above normal for 30 seconds.
The ECM has been powered for at least 2 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 for 30 seconds.
The ECM has been powered for 2 seconds.    
1589-3 Turbocharger Inlet Air Pressure Sensor voltage above normal     The ECM detects signal voltage that is above normal for one second.
The ECM has been powered for at least 3 seconds.     The code is logged.
The value of the parameter is set to zero.    
1589-4 Turbocharger Inlet Air Pressure Sensor voltage below normal     The ECM detects signal voltage that is below normal for one second.
The ECM has been powered for 3 seconds.    
1785-3 Intake Manifold Pressure Sensor voltage above normal     The ECM detects signal voltage that is above normal for 2 seconds.
The ECM has been powered for at least 2 seconds.     The code is logged.
The value of the parameter is set to a gauge pressure of zero.
   
1785-4 Intake Manifold Pressure Sensor voltage below normal     The ECM detects signal voltage that is below normal for 2 seconds.
The ECM has been powered for 2 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 30 seconds. Engine speed must be above 1000 rpm.
The ECM has been powered for 2 seconds.    System OperationUse this procedure to troubleshoot any suspect problems with the following sensors:
Fuel pressure sensor
Engine oil pressure sensor
Atmospheric pressure sensor
Turbocharger inlet pressure sensor
Intake manifold pressure sensorThe 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 5 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 g03428500
Typical schematic
Illustration 2 g01145897
P1 ECM connector (P1-2) Sensor supply (P1-3) Sensor return (P1-15) Turbocharger inlet pressure sensor
Illustration 3 g01024457
P2 ECM connector (P2-15) Intake manifold pressure sensor (P2-17) Sensor return (P2-28) Engine oil pressure sensor (P2-40) Fuel pressure sensor (P2-57) Atmospheric pressure sensor (P2-72) Sensor supply
Illustration 4 g01159881
Sensor connector (A) 5 V sensor supply (B) Sensor return (C) Signal
Illustration 5 g01200216
Locations of the pressure sensors (typical left side engine view) (1) Atmospheric pressure sensor (2) Fuel pressure sensor (3) Intake manifold pressure sensor (4) Engine oil pressure sensor (5) J2/P2 ECM connectors (6) J1/P1 ECM connectors
Illustration 6 g01142856
Air filter assembly (7) Turbocharger inlet pressure sensorTest Step 1. Check for "Active" or "Logged" Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the START 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 a