BLOCK 8P6613 - Caterpillar

Illustration 3 g01394757
P1 terminals that are associated with the cooling fan speed (P1-29) Sensor return (P1-35) +8 V digital supply
Illustration 4 g01394760
P2 terminal that is associated with the cooling fan speed (P2-25) Engine fan speed
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the Cat Data Link.
Check the allen head screw on each ECM connector for the proper torque. Also, check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.Expected Result:All connectors, pins, and sockets are completely inserted and coupled. 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 the Status of the Engine Fan Speed with Caterpillar Electronic Technician (ET)
Connect Cat ET to the service tool connector.
Restore electrical power to the ECM. Start the engine.
Compare the status for "Engine Fan Speed" to the status for "Desired Engine Fan Speed" on ET.
Remove electrical power from the ECM.Expected Result:"Engine Fan Speed" is within 50 rpm of "Desired Engine Fan Speed".Results:
OK - The engine fan speed is within the desired rpm range.Repair: The sensor is operating correctly. There may be an intermittent electrical problem in a connector or in the harness. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - The engine fan speed is not within the desired rpm range. Proceed to Test Step 3.Test Step 3. Check the Digital Sensor Supply Voltage at the Sensor Connector
Disconnect the connector for the engine cooling fan speed sensor.
Restore electrical power to the ECM.
Measure the voltage across terminal A (+8 V digital supply) and terminal B (sensor return).
Disconnect the connector for the engine cooling fan speed sensor.
Remove electrical power from the ECM.Expected Result:The digital sensor supply voltage should be 8.0 0.5 VDC.Results:
OK - The supply voltage is reaching the sensor. Proceed to Test Step 4.
Not OK - The supply voltage is not reaching the sensor. Proceed to Test Step 5.Test Step 4. Check for Shorts in the Harness From the Fan Speed Sensor to the ECM
Disconnect the ECM connectors J1/P1 and J2/P2.
Disconnect the connector for the engine cooling fan speed sensor.
Measure the resistance between terminal P1-35 (+8 V digital supply) and chassis ground.
Measure the resistance between terminal P1-35 (+8 V digital supply) and all of the