13203-956U0 Suzuki 3RD CARBURETOR ASSEMBLY

Table 1
Diagnostic Codes Table    
Description     Conditions which Generate this Code     System Response    
91-2 Throttle Position Sensor erratic, intermittent, or incorrect     The Electronic Control Module (ECM) has detected an invalid combination of positions for the multi-position switches.     The code is logged.
If equipped, the warning light will come on.
Engine RPM defaults to a predetermined safe speed.
The throttle switch is ignored by the ECM until the fault is cleared and the keyswitch is cycled.    
91-3 Throttle Position Sensor voltage above normal     The ECM has detected voltage that is above the accepted range.     The code is logged.
If equipped, the warning light will come on.
Engine RPM defaults to a predetermined safe speed.
The throttle switch is ignored by the ECM until the fault is cleared and the keyswitch is cycled.    
91-4 Throttle Position Sensor voltage below normal     The ECM has detected voltage that is below the accepted range.     The code is logged.
If equipped, the warning light will come on.
Engine RPM defaults to a predetermined safe speed.
The throttle switch is ignored by the ECM until the fault is cleared and the keyswitch is cycled.    
91-8 Throttle Position Sensor abnormal frequency, pulse width, or period     The ECM has detected an erratic multi-position switch.     The code is logged.
If equipped, the warning light will come on.
Engine RPM defaults to a predetermined safe speed.    Note: Certain applications will determine the desired engine speed within the machine ECM. The desired engine speed will then be sent to the engine ECM for implementation.The throttle switch provides the operator with the ability to select the desired engine speed. The throttle switch configuration may be selected between 0 to 4 switches. A multi-position rotary switch may be used.The throttle switch is connected to the four throttle inputs of the ECM. Each position generates a specific on/off pattern on the throttle inputs. A diagnostic code is generated if a pattern that does not correspond with any of the switch positions is detected.Once a diagnostic code is generated, the ECM ignores the throttle input signals and the desired engine speed is set to 1200 rpm, unless the actual engine speed is below 1200 rpm. If the actual engine speed is below 1200 rpm, the desired engine speed is set to the current engine speed. The desired engine speed is set to low idle if the engine is not running.Caterpillar Electronic Technician (ET) can be used to view the status of the inputs for the throttle switch.
Illustration 1 g01347275
Schematic for the throttle switch
Illustration 2 g01347281
Typical view of the pin locations for the throttle switch on the P1 connector (35) Switch return (52) Throttle position switch 1 (51) Throttle position switch 2 (50) Throttle position switch 3 (49) Throttle position switch 4Test Step 1. Inspect Electrical Connectors and Wiring
Remove the electrical power from the ECM.
Thoroughly inspect the J1/P1 ECM connector. Refer to service Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01250541
Terminal locations at the throttle switch (Terminal 1) Return (Terminal 2) Throttle input #1 (Terminal 3) Throttle input #2 (Terminal 4) Throttle input #3 (Terminal 5) Throttle input #4 (Terminal 6) Open
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and at the connector for the throttle switch.
Check the allen head screw for each of the ECM connectors for the proper torque. Refer to service Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for corrosion, for abrasion, and for pinch points from the throttle switch 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 connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.If applicable, perform a "Wiggle Test" by using Cat ET in order to identify intermittent connections.Use Cat ET in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 2. Check "Throttle Cab Switch Position" on Cat ET
Connect the electronic service tool to the diagnostic connector.
Restore the electrical power to the ECM.
Observe the status of the throttle switch and the throttle inputs on Cat ET while you operate the throttle switch in each position.Expected Result:The throttle switch is functioning correctly.Results:
OK - The throttle switch is functioning correctly.Repair: Refer to service Troubleshooting, "Electrical Connectors - Inspect" if the fault is intermittent.STOP
Not OK - The throttle switch is not functioning correctly. Record the suspect input. Proceed to Test Step 3.Test Step 3. Jumper the Switch Input at the Throttle Switch Connector
Disconnect the throttle switch connector.
Observe the status of the suspect throttle input on Cat ET.
Use a suitable jumper wire to short terminal 1 to the terminal for the suspect throttle input at the throttle switch connector.
Observe the status of the suspect throttle input onCat ET.
Remove the jumper wire.Expected Result:The status of the suspect throttle input is OFF when the throttle switch connector is disconnected. The status is ON when the jumper wire is installed.Results:
OK - There is a problem with the throttle switch. The harness and the ECM are OK.Repair: Replace the throttle switch.Use Cat ET in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOP
Not OK - There is a problem with the harness and/or the ECM. Proceed to Test Step 4.Test Step 4. Check for Shorts in the Harness
Remove the electrical power from the ECM.
Disconnect the P1 connector and the throttle switch connector.
Measure the resistance between engine ground and the terminal for the suspect throttle input at the throttle switch connector .
Measure the resistance between the terminal for the suspect throttle input at the throttle switch connector and the remaining terminals at the connector.Expected Result:Resistance is greater than 20,000 Ohms for each