3A3-84428-0 Tohatsu THROTTLE FRICTION ARM

Table 1
Diagnostic Codes Table    
Description     Conditions which Generate this Code     System Response    
262-3 5 Volt Sensor DC Power Supply voltage above normal     The analog sensor supply voltage is above normal for two seconds.     The code is logged.
All sensors are set to default values.    
262-4 5 Volt Sensor DC Power Supply voltage below normal     The analog sensor supply voltage is below normal for two seconds.    
263-3 Digital Sensor Power Supply (8V Or 12V) voltage above normal     The digital sensor supply voltage is above normal for two seconds.    
263-4 Digital Sensor Power Supply (8V Or 12V) voltage below normal     The digital sensor supply voltage is below normal for two seconds.    System OperationThe Electronic Control Module (ECM) supplies a regulated voltage of 5.0 0.2 VDC to the following sensors:
Atmospheric pressure sensor
Coolant temperature sensor
Crankcase pressure sensor
Filtered engine oil pressure sensor
Filtered fuel pressure sensor
Turbocharger outlet pressure sensor
Left turbocharger inlet pressure sensor
Right turbocharger inlet pressure sensor
Unfiltered engine oil pressure sensor
Unfiltered fuel pressure sensorThe ECM supplies a regulated voltage of 8.0 0.4 VDC to the following sensors:
Left exhaust temperature sensor
Right exhaust temperature sensorThe supply voltage for the sensors is routed from the ECM to terminal A of each sensor connector. The sensor return for the sensors is routed from the ECM to terminal B 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.Note: The sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. If the diagnostic code 262-3 or the diagnostic code 263-3 is logged, it is possible that all of the sensors have been damaged. Repair the sensor supply and check for any active sensor diagnostic codes in order to determine if a sensor has failed.
Illustration 1 g01212476
Typical schematic
Illustration 2 g01212477
Typical 8 V supply
Illustration 3 g01212479
P1 ECM connector (P1-2) 5 V sensor supply (P1-3) Sensor return (P1-4) 8 V supply (P1-5) Digital return (P1-7) Coolant temperature sensor (P1-11) Left exhaust temperature (P1-12) Right exhaust temperature (P1-16) Filtered engine oil pressure sensor (P1-17) Unfiltered engine oil pressure sensor (P1-24) Filtered fuel pressure (P1-25) Unfiltered fuel pressure
Illustration 4 g01288476
P2 ECM connector (P2-36) Turbocharger outlet pressure sensor (P2-37) Atmospheric sensor (P2-38) Left turbocharger inlet pressure sensor (P2-39) Right turbocharger inlet pressure sensor (P2-46) Crankcase pressure sensor
Illustration 5 g01094844
Sensor connector (Pin A) Sensor supply (Pin B) Sensor return (Pin C) SignalTest Step 1. Inspect Electrical Connectors and Wiring
Turn the "main disconnect switch (MDS)" to the OFF position.
Thoroughly inspect the J1/P1 ECM connector and the J2/P2 ECM connector. Inspect all of the connectors that are associated with the circuit.Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM.Expected Result:All connectors, pins and sockets are completely coupled and/or inserted and 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 with 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.Verify that the repair eliminates the problem.STOPTest Step 2. Check for Active Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the "MDS" to the ON position.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Look for the following diagnostic codes:
262-3
262-4
263-3
263-4 Note: Wait at least 30 seconds in order for the diagnostic codes to become active.Expected Result:No diagnostic codes are active.Results:
OK - No diagnostic code is active.Repair: The problem is no longer present. If the problem is intermittent, refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - Either the 262-3 or 262-4 diagnostic code is active at this time. Proceed to Test Step 3.
Not OK - Either the 263-3 or 263-4 diagnostic code is active at this time. Proceed to Test Step 5.Test Step 3. Disconnect the 5 Volt Sensors while you Monitor the Active Diagnostic Codes
Monitor the active diagnostic code screen on Cat ET while you disconnect each 5 Volt sensor at the sensor connector. Check for an active 262-3 code or an active 262-4 code.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Disconnect the following sensors one at a time:
Atmospheric pressure sensor
Coolant temperature sensor
Crankcase pressure sensor
Filtered engine oil pressure sensor
Filtered fuel pressure sensor
Turbocharger outlet pressure sensor
Left turbocharger inlet pressure sensor
Right turbocharger inlet pressure sensor
Unfiltered engine oil pressure sensor
Unfiltered fuel pressure sensor
Turn the "MDS" to the OFF position.Expected Result:The diagnostic code deactivates when a particular sensor is disconnected.Results:
OK - The 262-3 or 262-4 diagnostic code deactivates when a particular sensor is disconnected.Repair: Connect the suspect sensor. If the code returns, replace th