The reverse direction enable tells the ECM that the operator wants the auxiliary hydraulics to operate in only one direction. The jumper is a 2-pin connector that connects to the wire harness at the integrated toolcarrier. When the jumper is installed, a grounded signal is received by pin 45 of the ECM. The ECM will disable the modulating valve (No. 2).
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| Illustration 1 | g00756171 |
Schematic for the circuit (reverse direction enable) | |
Test Step 1. CHECK FOR PROPER OPERATION
- Install the jumper (reverse direction enable).
- Run the machine.
- Actuate the auxiliary control to the left.
- Actuate the auxiliary control to the right.
Expected Result:
The auxiliary hydraulics should operate in the right position and the auxiliary hydraulics should not operate in the left position.
Results:
- OK - The auxiliary hydraulics will operate in the right position and the auxiliary hydraulics will not operate in the left position.
Repair: There is no problem at this time. Check the wire harness for loose connections.
Stop.
- NOT OK - The auxiliary hydraulics will operate in the right position and in the left position. Proceed to Test Step 2.
- NOT OK - The auxiliary hydraulics will not operate in the right position and the auxiliary hydraulics will not operate in the left position.
Repair: See Troubleshooting Section, "Auxiliary Hydraulic Does Not Function in Either Direction".
Stop.
Test Step 2. CHECK FOR OPERATION OF THE CIRCUIT
- Turn the key start switch to the OFF position.
- Connect the Caterpillar ET to the CAT data link.
- Turn the key start switch to the ON position.
- Open the file "auxiliary hydraulic ECM".
- Check the status of the reverse direction enable for an "Open" or a "Close".
Expected Result:
The status of the "reverse direction enable" should display "Closed".
Results:
- OK - The status of the "reverse direction enable" displays "Closed".
Repair: See Troubleshooting Section, "Auxiliary Hydraulic Does Not Function in One Direction".
Stop.
- NOT OK - The status of the "reverse direction enable" displays "Open". Proceed to Test Step3.
Test Step 3. CHECK THE CONTINUITY OF THE CIRCUIT
- Remove the operator control panel on the right side in order to get to the ECM.
- Remove the wire harness from the ECM.
- Measure the resistance from contact 3 to contact 45.
Expected Result:
The resistance should be less than 5 Ohms.
Results:
- OK - The resistance is less than 5 Ohms.
Repair: The ECM is very unlikely to have failed. Perform the Test Steps again and verify all results.Replace the ECM, if the problem is occurring after the second attempt. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
Stop.
- NOT OK - The resistance is greater than 5 Ohms.
Repair: The circuit is open in the wire harness and/or the connector. Repair the wire harness and/or the connector or replace the wire harness and/or the connector.
Stop.