SLIP JOINT GP 3353240 - Caterpillar

Illustration 1 g01368845
Left secondary brake switch (parking brake switch) connections shown in the brake ON (engaged) position (dump solenoid energized)
Illustration 2 g01220728
Mechanical actuator for the left secondary brake switch (parking brake switch)This diagnostic code is associated with the left secondary brake switch (park brake switch). The parking brake dump solenoid will be energized when the switch is in the ON (brake engaged) position. Under certain machine conditions, the solenoid can be energized by the power train ECM using the ON/OFF output circuit at contact J2-3. The ECM monitors the two switch to ground type inputs from the switch in order to determine the status of the switch. The ECM also monitors the switch energize circuit at the ON/OFF output.When the ECM detects that the parking brake switch is in the ON (brake engaged) position, the ECM expects to detect the solenoid energize voltage (system voltage) that is directed through the switch contacts at the J2-3 contact. If the ECM DOES NOT detect this system voltage when the parking brake switch is in the ON (brake engaged) position, the ECM will activate the CID 0618 FMI 02 diagnostic code.Some conditions that can cause this diagnostic code to be activated are:
The implement drive train fuse is open.
The switch has failed.
An open circuit exists in the switch energize circuit.
The ECM has failed. This is unlikely.
Table 1
Parking Brake Switch Contact States    
    Parking Brake ON (Engaged)     Parking Brake OFF (Disengaged)    
Switch Contact 7 (wire G730-PK)     Closed (2)     Open (1)    
( 2 ) Closed to supply contact 9 (wire 176-OR).
( 1 ) Open to supply contact 9 (wire 176-OR).Note: Before performing this procedure, check to see if the ECM has activated any CID 0681 (parking brake solenoid) diagnostic codes. Some of the same conditions that can cause the ECM to activate the CID 0681 code can also activate the CID 0618 code. Correct the problem and clear an active CID 0681 diagnostic code. Then verify that the CID 0618 diagnostic code is still active.Note: Before performing this procedure, verify that the 15 amp implement drive train fuse is not open. An open fuse would result in this diagnostic code and other diagnostic codes being activated.Test Step 1. CHECK THE SWITCH OPERATION
Turn the disconnect switch and the key switch to the OFF position.
Disconnect the machine harness connector from the parking brake switch connector.
At the switch connector, measure the resistance (continuity) between energize contact 7 and the supply contact 9 when the switch is in the "ON" position and when the switch is in the "OFF" position.Expected Result:When the switch is in the ON position, the resistance measurement between switch contact 7 and switch contact 9 is less than 5.0 ohms. When the switch is in the OFF position, the resistance measurement between switch contact 7 and switch contact 9 is greater than 5000 ohms.Results:
OK - The switch contact states are correct when the switch is in the ON position and when the switch is in the OFF position. The switch