SPOOL (1.3616" DIA.) 7M8595 - Caterpillar

Illustration 1 g00763235
Schematic of the retarder solenoid circuitNote: The approximate coil resistance of the solenoid is 2.2 .2 ohms at 25 °C (77.0 °F).This diagnostic code is recorded when the ECM reads the voltage of the solenoid circuit as above normal (short to the +battery circuit).Note: This procedure can cause new diagnostic codes to be recorded. Ignore these created diagnostic codes. Complete the following procedure. Then clear the created diagnostic codes.Test Step 1. CHECK THE SIGNAL CIRCUIT OF THE SOLENOID FOR A SHORT.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the solenoid.
Disconnect the machine harness connectors J1 and J2 from the ECM.
At the J1 and J2 machine harness connectors for the ECM, measure the resistance from the signal contact of the solenoid J2-41 (wire K744-BU) to the +battery circuit. The possible sources of positive voltage are contacts: J1-11, J1-58, J2-1, J2-15, J2-16, J2-17, J2-23, J2-25, J1-39, J2-40, J2-44, J2-45, J2-47, J2-51, J2-57, J2-58, J2-60, J2-62, J2-63, J2-64, J2-65, J2-68 and J2-70.Expected Result:Each resistance should be greater than 5000 ohms.Results:
YES - The machine harness is correct. Proceed to test step 2.
NO - There is a short in the machine harness.Repair: The short is between the signal contact of the solenoid and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness. Stop.Test Step 2. CHECK IF THE DIAGNOSTIC CODE REMAINS.
Inspect the contacts and clean the contacts of the harness connectors.
Reconnect all harness connectors.
Turn the disconnect switch and the key start switch to the ON position.
Clear all of the inactive diagnostic codes.
Operate the machine.
Stop the machine. Then place the parking brake switch in the ON position.
Observe the status of the diagnostic code. The diagnostic code is present or the diagnostic code is NOT present.Expected Result:The diagnostic code for the solenoid is NO longer present.Results:
YES - The diagnostic code is NOT present. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor electrical connection and/or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation. Stop.
NO - The diagnostic code has not been corrected. The ECM has failed.Repair: It is unlikely that the ECMhas failed. Exit this procedure and perform this diagnostic code procedure again. Recheck the status of the diagnostic code. The diagnostic code is active or the diagnostic code is NOT active. Replace the ECM if the cause is not found. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace". Stop.