0337791 JOHNSON COVER, Air intake

Illustration 1 g00634731
Typical example
Illustration 2 g01072115
P1 ECM connector (P1-29) Digital return (P1-35) 8 V digital supplyTest Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF position.
Thoroughly inspect the ECM connectors J1/P1. Inspect all of the sensor connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details on inspecting connectors.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the customer connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the harness and the wiring for abrasion and for pinch points.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 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 the Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch 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:None of the following diagnostic codes are active:
263-03
263-04 Results:
OK - No diagnostic codes are active.Repair: The problem may have been related to a faulty connection in the harness. Carefully reinspect the connectors and wiring. Refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - A 263-03 diagnostic code is active. Proceed to Test Step 3.
Not OK - A 263-04 diagnostic code is active. Proceed to Test Step 4.Test Step 3. Check the Voltage on the +8 V Supply Wire at the Sensor Connector
Turn the keyswitch to the OFF position.
Disconnect all of the following digital sensors at the sensor connector:
Right exhaust temperature sensor
Left exhaust temperature sensor
Throttle position sensor
Engine fan speed sensor
Turn the keyswitch to the ON position.
Measure the voltage between terminal A and terminal B at the sensor connectors.Expected Result:The voltage is 8.0 0.4 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 Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - The voltage is incorrect. Proceed to Test Step 5.Test Step 4. Disconnect the +8 V Sensors while you Monitor the Active Diagnostic Codes
Monitor the active diagnostic code screen on the electronic service tool. 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:
Right exhaust temperature sensor
Left exhaust temperature sensor
Throttle position sensor
Engine fan speed sensor
Wait for 15 seconds after each sensor is disconnected. Check for an active diagnostic code on the electronic service tool.Expected Result:The 263-04 diagnostic code deactivates.Results:
OK - The 263-04 diagnostic code deactivates. The diagnostic code is not active after a specific sensor is disconnected.Repair: Reconnect the sensor that is suspected of causing the problem. If the problem returns after the reconnection of the sensor, disconnect the sensor. If the problem disappears after the disconnection of the sensor, replace the sensor. Replace all wires to the original configuration. Clear all diagnostic codes. Verify that the repair eliminates the problem.STOP
Not OK - The 263-04 diagnostic code stays active. Leave the sensors disconnected. Proceed to Test Step 5.Test Step 5. Check the +8 V Supply Wire for a Short to Engine Ground or a Short to another Wire in the Harness
Turn the keyswitch to the OFF position.
Disconnect the J1/P1 ECM connector and the J2/P2 ECM connector.
Leave the digital sensors disconnected at the sensor connectors.Note: Wiggle the harness during the following measurements in order to reveal any intermittent short condition.
Measure the resistance from the ECM connector P1-35 (+8 V Supply) to every terminal on ECM connector P1 and ECM connector P2.
Measure the resistance from the ECM connector P1-35 to the ECM ground strap.
Reconnect all connectors.Expected Result:Each resistance measurement is more than 20,000 Ohms.Results:
OK - The resistance check does not indicate a short in the engine harness or a short to engine ground. Proceed to Test Step 6.
Not OK - A resistance measurement is less than 20,000 Ohms. The +8 V supply wire is shorted in the engine harness or the +8 V supply wire is shorted to engine ground.Repair: Repair the wire or replace the wire. Clear all logged diagnostic codes. Replace all wires to the original configuration. Verify that the repair eliminates the problem.STOPTest Step 6. Check the +8 V Supply and the Sensor Common for an Open Circuit
Install a wire jumper between terminal P1-35 (+8 V Supply) and terminal P1-29 (Sensor Common).Note: Wiggle the harness during the following measurements in order to reveal any intermittent short condition.
Record the resistance at the connector for the right exhaust temperature sensor between terminal A and terminal B.
Remove the wire jumper.Expected Result:The resistance is less than 5 Ohms for each measurement.Results:
OK - The resistance check does not indicate an open circuit in the engine harness. Proceed to Test Step 7.
Not OK - A resistance measurement is greater than 5 Ohms. The +8 V supply wire or the sensor common has excessive resistance.Repair: Repair the wires or replace the wires. Clear all logged diagnostic codes. Replace all wires to the original configuration. Verify that the repair eliminates the problem.STOPTest Step 7. Check the +8 V Supply at the ECM
Remove the digital supply line on terminal P1-35 of the ECM. Install a wire jumper with socket terminals on both ends into P1-35.
Remove the digital return line on terminal P1-29 of the ECM. Install a wire jumper with socket terminals on both ends into P1-29.Note: Disconnecting the common sensor wire from the ECM will generate an