13201-956U0 Suzuki TOP CARBURETOR ASSEMBLY

Table 1
Diagnostic Codes Table    
Description    Conditions which Generate this Code    System Response    
100-3 Engine Oil Pressure Sensor voltage above normal     The Electronic Control Module (ECM) detects signal voltage above normal for eight seconds.
The engine is not running or coolant temperature is greater than
38 °C (100 °F).     The code is logged.
If equipped, the warning light will illuminate.
The ECM will set engine oil pressure to a default value.    
100-4 Engine Oil Pressure Sensor voltage below normal     The ECM detects signal voltage below normal for eight seconds.
The engine is running.     The code is logged.
If equipped, the warning light will illuminate.
The ECM will set engine oil pressure to a default value.    
1785-3 Intake Manifold Pressure Sensor voltage above normal     The ECM detects signal voltage above normal for two seconds.     The code is logged.
If equipped, the warning light will illuminate.
The ECM will set intake manifold (boost) pressure to a maximum valid pressure for two seconds. The ECM will then set intake manifold (boost) pressure to a default value.    
1785-4 Intake Manifold Pressure Sensor voltage below normal     The ECM detects signal voltage below normal for two seconds.     The code is logged.
If equipped, the warning light will illuminate.
The ECM will set intake manifold (boost) pressure to a maximum valid pressure for two seconds. The ECM will then set intake manifold (boost) pressure to a default value.    
1797-3 Fuel Rail Pressure Sensor voltage above normal     The ECM detects signal voltage above normal for two seconds.     The code is logged.
If equipped, the warning light will illuminate.
The engine will be derated.    
1797-4 Fuel Rail Pressure Sensor voltage below normal     The ECM detects signal voltage below normal for two seconds.     The code is logged.
If equipped, the warning light will illuminate.
The engine will be derated.    The troubleshooting procedures for the diagnostic codes of each pressure sensor are identical. The 5 volt sensor supply provides power to all 5 volt sensors. The ECM supplies 5.0 0.2 VDC to terminal "A" of each sensor connector. The sensor common from the ECM connector goes to terminal "B" of each sensor connector. The sensor supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM.Pull-up VoltageThe ECM continuously outputs a pull-up voltage on the circuit for the sensor signal wire. The ECM uses this pull-up voltage in order to detect an open in the signal circuit. When the ECM detects the presence of a voltage that is above a threshold on the signal circuit, the ECM will generate an open circuit diagnostic code (3) for the sensor.If the sensor is disconnected at the sensor connector, 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. If the sensor is disconnected at the sensor connector, the absence of pull-up voltage at the sensor connector indicates an open in the signal wire or a short to ground. If the sensor is disconnected at the sensor connector and the voltage at the sensor connector is different from pull-up voltage, the signal wire is shorted to another wire in the harness.
Illustration 1 g01323286
Typical example of the schematic for the sensors
Illustration 2 g01170309
Typical pressure sensor (1) Voltage supply (2) Sensor return (3) Signal Test Step 1. Inspect Electrical Connectors And Wiring.
Illustration 3 g01346894
Typical view of the P2 pressure sensor pin locations (38) Intake manifold pressure sensor return (39) Oil pressure sensor return (40) Fuel rail pressure sensor return (46) Intake manifold pressure sensor + 5V supply (47) Oil pressure sensor + 5V supply (48) Fuel rail pressure sensor +5V supply (51) Signal fuel rail pressure sensor (55) Signal intake manifold pressure sensor (56) Signal oil pressure sensor
Remove the electrical power from the ECM.
Thoroughly inspect the terminal connections on the P2/J2 ECM connectors. Thoroughly inspect the connectors for each engine pressure sensor.
Refer to service Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the engine pressure sensors.
Check the torque of the allen head screws for the ECM connectors. Refer to service Troubleshooting, "Electrical Connectors - Inspect".
Check the harness for abrasions and for pinch points from the sensors back to the ECM.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the wiring and/or the connectors.Repair: Repair the connectors or the harness and/or replace the connectors or the harness. Ensure that all of the seals are correctly in place and ensure that the connectors are completely coupled.Use Caterpillar Electronic Technician (ET) in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.If applicable, use Cat ET to perform a "Wiggle Test".STOPTest Step 2. Check the Voltage on the +5 V Supply Wire
Remove the electrical power from the ECM.
Disconnect the harness connectors for the pressure sensors.
Restore the electrical power to the ECM.
Measure the voltage between terminals 1 (+5 VDC) and 2 (Return) at each sensor connector on the engine harness.
Remove the electrical power from the ECM.
Connect all of the sensors.Expected Result:Each voltage measurement is 5.0 0.2 VDC.Results:
OK - Each voltage measurement is 5.0 0.2 VDC. Proceed to Test Step 3.
Not OK - At least one voltage measurement is not 5.0 0.20 VDC.Repair: Refer to the circuit test Troubleshooting, "Sensor Supply - Test".STOPTest Step 3. Check for Active Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector. Refer to the introduction Troubleshooting, "Electronic Service Tools".
Restore the electrical power to the ECM.
Observe the "Active Diagnostic" screen on Cat ET. Wait at least 30 seconds so that any codes may become active. Look for an active diagnostic code for an engine pressure sensor.
Determine if the problem is related to a -3 diagnostic