0389992 JOHNSON CARB ASSY., Lower 150 only

Illustration 1 g01161442
Schematic
Illustration 2 g01161474
P1 ECM connector
(P1-2) Analog sensor power
(P1-3) Analog sensor common
(P1-6) Aftercooler temperature
(P1-7) Coolant temperature
(P1-16) Filtered oil pressure
(P1-17) Unfiltered oil pressure
(P1-18) Analog sensor power
(P1-35) Analog sensor common
(P1-24) Filtered fuel pressure
(P1-25) Unfiltered fuel pressure
Illustration 3 g01161487
P2 ECM connector
(P2-3) Atmospheric pressure
(P2-36) Turbocharger outlet pressure
(P2-38) Left turbocharger inlet pressure
(P2-39) Right turbocharger inlet pressure
(P2-46) Crankcase pressure
Illustration 4 g01094844
Sensor connector
Illustration 5 g01142488
Typical sensor locations
(1) Engine oil pressure sensor
Illustration 6 g01161501
Typical sensor locations
(2) Turbocharger inlet pressure sensor
(3) Boost pressure sensor
(4) Filtered fuel pressure sensor
(5) Inlet manifold pressure sensor
(6) Atmospheric pressure sensor
(7) Unfiltered fuel pressure sensor Test Step 1. Inspect Electrical Connectors and Wiring
Turn the battery disconnect switch 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 3.
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 battery disconnect switch to the ON position.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Note: Wait at least 15 seconds in order for the diagnostic codes to become active.Expected Result:One of the following diagnostic codes is active:
262-03
262-04 Results:
OK - A 262-03 diagnostic code is active. Proceed to Test Step 3.
OK - A 262-04 diagnostic code is active. Proceed to Test Step 4.
Not OK - No diagnostic code is active.Repair: The problem is no longer present. If the problem is intermittent, refer to Troubleshooting, "Inspecting Electrical Connectors".STOPTest Step 3. Check the Supply Voltage at the Sensor Connector
Turn the battery disconnect switch to the OFF position.
Disconnect all of the following analog sensors at the sensor connector:
Coolant temperature sensor
Aftercooler temperature sensor
Unfiltered engine oil pressure sensor
Filtered engine oil pressure sensor
Left turbocharger inlet pressure sensor
Right turbocharger inlet pressure sensor
Atmospheric pressure sensor
Crankcase pressure sensor
Turbocharger outlet pressure sensor
Unfiltered fuel pressure sensor
Filtered fuel pressure sensor
Turn the battery disconnect switch to the ON position.
Measure the voltage between terminal A (5 V analog supply) and terminal B (sensor common) at the sensor connectors.
Turn the battery disconnect switch to the OFF position.
Reconnect all of the sensors. Expected Result:The voltage is 5.0 0.2 VDC.Results:
OK - The voltage is correct.Repair: Replace all wires to the original configuration. Clear all diagnostic codes. Check for active diagnostic codes. If the problem is intermittent, refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - The voltage is not 5.0 0.2 VDC. The voltage is incorrect. Proceed to Test Step 5.Test Step 4. Disconnect the +5 V Sensors while you Monitor the Active Diagnostic Codes
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Note: Wait at least 15 seconds in order for the diagnostic codes to become active.
Disconnect the following sensors one at a time at the sensor connector as you monitor Cat ET:
Coolant temperature sensor
Aftercooler temperature sensor