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Parking brake won't release on cat 236B skidsteer

jimprater

Member
Joined
Feb 18, 2015
Messages
6
Location
Fruitvale, TX
When the engine starts the parking brake and the man with the seatbelt flash and I can't get them to turn off in order to move the machine.
 

Mobiltech

Senior Member
Joined
Jan 14, 2014
Messages
1,705
Location
Sask.
Occupation
Self employed Heavy duty mechanic
If both are flashing it indicates a fault in the pilot lock solenoid wiring.





A.Occupy the seat.

B.Place the armrest in the DOWN position.

C.Turn the key start switch to the ON position.

Expected Result:

The armrest indicator should be off and the parking brake indicator should be on.

Results:

•OK - The armrest indicator is off and the parking brake indicator is on. Proceed to Test Step 9.

•NOT OK - The armrest indicator is flashing and the parking brake indicator is flashing. Proceed to Test Step 2.

•NOT OK - The parking brake indicator is flashing.
Repair: See Troubleshooting, "Parking Brake Indicator Is Flashing".

Stop.


•NOT OK - The armrest indicator is flashing.
Repair: See Troubleshooting, "Armrest Indicator Is Flashing".

Stop.


Test Step 2. CHECK THE RETURN SOLENOID WIRE FOR A SHORT TO GROUND

A.Turn the key start switch to the OFF position.

B.Raise the cab. See Operation and Maintenance Manual, "Cab Tilting".

C.Locate the interlock ECM. The interlock ECM is located on the left side of the machine beneath the access cover on the floor of the machine.

D.Remove the wire harness from the ECM.

E.Measure the resistance from contact 3 to contact 68 (wire 201-BK and wire 975-WH) of the wire harness connector.

Expected Result:

The resistance should be greater than 5000 Ohms.

Results:

•OK - The resistance is greater than 5000 Ohms. Proceed to Test Step 6.

•NOT OK - The resistance is not greater than 5000 Ohms. Proceed to Test Step 3.

Test Step 3. CHECK THE HYDROSTATIC PILOT SOLENOID FOR A SHORT TO GROUND

A.Locate the hydrostatic pilot solenoid.

B.Disconnect the wire harness from the hydrostatic pilot solenoid.

C.Measure the resistance from contact 3 to contact 68 (wire 201-BK and wire 975-WH) of the wire harness for the ECM.

Expected Result:

The resistance should be greater than 5000 Ohms.

Results:

•OK - The resistance is greater than 5000 Ohms.
Repair: The hydrostatic pilot solenoid has failed. Replace the coil for the hydrostatic pilot solenoid.

Stop.


•NOT OK - The resistance is not greater than 5000 Ohms. Proceed to Test Step 4.

Test Step 4. CHECK THE WORK TOOL PILOT SOLENOID FOR A SHORT TO GROUND

A.Locate the work tool pilot solenoid.

B.Disconnect the wire harness from the work tool pilot solenoid.

C.Measure the resistance from contact 3 to contact 68 (wire 201-BK and wire 975-WH) of the wire harness for the ECM.

Expected Result:

The resistance should be greater than 5000 Ohms.

Results:

•OK - The resistance is greater than 5000 Ohms.
Repair: The work tool pilot solenoid has failed. Replace the coil for the work tool pilot solenoid.

Stop.


•NOT OK - The resistance is not greater than 5000 Ohms. Proceed to Test Step 5.

Test Step 5. CHECK THE WORK TOOL DETENT COIL FOR A SHORT TO GROUND

A.Locate the work tool detent coil. The detent coil is located beneath the right hand joystick. Remove the access panel in order to get to the connector.

B.Disconnect the wire harness from the work tool detent coil.

C.Measure the resistance from contact 3 to contact 68 (wire 201-BK and wire 975-WH) of the wire harness for the ECM.

Expected Result:

The resistance should be greater than 5000 Ohms.

Results:

•OK - The resistance is greater than 5000 Ohms.
Repair: The work tool detent coil has failed. Replace the coil for the work tool detent coil.

Stop.


•NOT OK - The resistance is not greater than 5000 Ohms.
Repair: The wire harness has failed. Repair the wire harness and/or the connector or replace the wire harness and/or the connector.

Stop.


Test Step 6. CHECK THE CIRCUIT FOR THE HYDROSTATIC PILOT SOLENOID FOR A SHORT TO THE + BATTERY TERMINAL

A.Measure the resistance at the wire harness connector from contact 29 (wire H416-GN) to the following contacts: contact 1, contact 11, contact 13, contact 24, contact 42, contact 47, contact 58, contact 60, contact 62 and contact 70.

Expected Result:

The resistances should be greater than 5000 Ohms.

Results:

•OK - The resistances are greater than 5000 Ohms. Proceed to Test Step 7.

•NOT OK - The resistance is not greater than 5000 Ohms on at least one of the readings.
Repair: The wire harness has failed. Repair the wire harness and/or the connector or replace the wire harness and/or the connector.

Stop.


Test Step 7. CHECK THE CIRCUIT OF THE WORK TOOL PILOT SOLENOID FOR A SHORT TO + BATTERY

A.Measure the resistance at the wire harness connector from contact 24 (wire 126-PK) to the following contacts: contact 1, contact 11, contact 13, contact 42, contact 47, contact 58, contact 60, contact 62 and contact 70.

Expected Result:

The resistances should be greater than 5000 Ohms.

Results:

•OK - The resistances are greater than 5000 Ohms. Proceed to Test Step 8.

•NOT OK - The resistance is not greater than 5000 Ohms on at least one of the readings.
Repair: The wire harness has failed. Repair the wire harness and/or the connector or replace the wire harness and/or the connector.

Stop.


Test Step 8. CHECK THE CIRCUIT OF THE WORK TOOL PILOT SOLENOID FOR A SHORT TO + BATTERY

A.Measure the resistance at the wire harness connector from contact 66 (wire 975-WH) to the following contacts: contact 1, contact 11, contact 13, contact 42, contact 47, contact 58, contact 60, contact 62 and contact 70.

Expected Result:

The resistances should be greater than 5000 Ohms.

Results:

•OK - The resistances are greater than 5000 Ohms.
Repair: The ECM is very unlikely to have failed. Reconnect all connections and visually inspect the wire harness. Verify that the diagnostic code still exists. If the diagnostic code still exists perform the Test Steps again.Replace the ECM, if the cause of the diagnostic code was not found after the second attempt. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

Stop.


•NOT OK - The resistance is not greater than 5000 Ohms on at least one of the readings.
Repair: The wire harness has failed. Repair the wire harness and/or the connector or replace the wire harness and/or the connector.

Stop.


Test Step 9. CHECK FOR A FLASHING PARKING BRAKE INDICATOR AND/OR A FLASHING ARMREST INDICATOR AFTER THE SYSTEM IS ENABLED

Note: The seat will still need to be occupied and the armrest will need to be down. The key start switch will also need to be in the ON position.

A.Press and release the parking brake switch.

Expected Result:

The armrest indicator and the parking brake indicator should be off.

Results:

•OK - The armrest indicator and the parking brake indicator are off.
Repair: There is no problem at this time.

Stop.


•NOT OK - Both indicators are flashing. Proceed to Test Step 10.

•NOT OK - The parking brake indicator is flashing.
Repair: See Troubleshooting, "Parking Brake Indicator Is Flashing".

Stop.


•NOT OK - The armrest indicator is flashing.
Repair: See Troubleshooting, "Armrest Indicator Is Flashing".

Stop.


Test Step 10. CHECK THE RETURN SOLENOID WIRE FOR AN OPEN CIRCUIT

A.Turn the key start switch to the OFF position.

B.Raise the cab. See Operation and Maintenance Manual, "Cab Tilting".

C.Locate the interlock ECM. The interlock ECM is located on the left side of the machine beneath the access cover on the floor of the machine.

D.Remove the wire harness from the ECM.

E.Measure the resistance from contact 29 to contact 68 (wire H416-GN to wire 975-WH) of the wire harness connector.

Expected Result:

The resistance should be approximately 11 Ohms.

Results:

•OK - The resistance is approximately 11 Ohms.
Repair: There is more than one problem. Start by troubleshooting one of the fault indicators. See Troubleshooting, "Parking Brake Indicator Is Flashing" or Troubleshooting, "Armrest Indicator Is Flashing".

Stop.


•NOT OK - The resistance is considerably greater than 11 Ohms.
Repair: There is an open in the return solenoid wire. Check all connections. Repair the wire harness and/or the connector or replace the wire harness and/or the connector.

Stop
 
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