SPIDER AS-FAN 2445929 - Caterpillar

Illustration 1 g00868989
Test Step 1. CHECK FOR AN ACTIVE DIAGNOSTIC CODE.
Place the control in service mode. See Troubleshooting, "Using the Diagnostic Indicator to Determine Diagnostic Codes".
Check for an active CID 0191 FMI 08, or CID 0442.Expected Result:The diagnostic code is active.Results:
YES - The diagnostic code is active. The transmission speed sensor's signal is NOT correct.Repair: See Troubleshooting, "MID 081 CID 0191 FMI 08 ". If the diagnostic procedure does not work, proceed to test step 2.
NO - The diagnostic code is NOT active. Proceed to test step 2.Test Step 2. CHECK THE POWER CIRCUITS TO THE SPEEDOMETER.
Turn the keyswitch to the ON.
Measure the voltage between the speedometer's power input and ground.Expected Result:The voltage that is measured does NOT vary from the battery voltage more than 0.5 DCV.Results:
YES - The voltage that is measured does NOT vary from the battery voltage more than 0.5 DCV. The power circuits are correct. Proceed to test step 3.
NO - The voltage that is measured varies from the battery voltage by more than 0.5 DCV. The power circuits have failed.Repair: Repair the power circuits or replace the power circuits. Stop.Test Step 3. CHECK THE SPEEDOMETER.
Disconnect the machine harness from the signal terminal of the speedometer.
Measure the resistance between the signal terminal and the ground terminal.Expected Result:The resistance should be between 65K ohms and 75K ohms.Results:
YES - The resistance is between 65K ohms and 75K ohms. The speedometer circuit is correct. Proceed to test step 4.
NO - The resistance is NOT between 65K ohms and 75K ohms. The speedometer circuit has failed.Repair: Repeat this test step. If the problem is still present, replace the speedometer. Stop.Test Step 4. CHECK THE HARNESS.
Disconnect the harness from the electronic control module (ECM).
Measure the resistance from the harness contact 2 and the harness contact 7.Expected Result:The resistance should be between 65 K ohms and 75K ohms.Results:
YES - The resistance is between 65K ohms and 75K ohms. The harness circuit is correct. The ECM has failed.Repair: It is unlikely that the ECM has failed. Exit this procedure and repeat this procedure. If the problem is still present, then proceed to Testing and Adjusting, "Electronic Control Module (ECM) - Replace". Stop.
NO - The resistance is NOT between 65K ohms and 75K ohms. The harness has failed.Repair: Repair the harness or replace the harness. Stop.