HOSE-HYDRAULIC 1226908 - Caterpillar

Table 1
Related Components: Possible Causes: Recommended Action:
Valve/Lines Idler or drive pump bypass stem is malfunctioning Refer to Troubleshooting, "Bypass Valve (ACS Valve) - Functional Test"
Warm-up valve failure
Main relief valve failure Refer to Troubleshooting, "Relief Valve (Main) - Functional Test"
Low-pressure setting on main relief
Stick Head End (HE) line relief valve failure Refer to Troubleshooting, "Relief Valve (Line) - Functional Test"
Combiner spool is malfunctioning Refer to Troubleshooting, "Flow Combiner Valve - Functional Test"
Stick Pump to Cylinder Head End (PCHE) Independent Metering Valve (IMV) spool is malfunctioning Refer to Troubleshooting, "IMV Calibration - Functional Test"(1)
Refer to Troubleshooting, "IMV Controllability Troubleshooting"(2)
Stick Pump to Cylinder Rod End (PCRE) IMV spool is malfunctioning
Stick Cylinder to Tank Rod End (CTRE) IMV spool is malfunctioning
Stick Drift Reduction Valve (DRV) is malfunctioning Refer to Troubleshooting, "Drift Reduction Valve - Functional Test"
Low pilot pressure Refer to Testing and Adjusting, KENR9615, "Relief Valve (Pilot) - Test and Adjust"
Compensator spool in stick IMV section is malfunctioning Refer to Troubleshooting, "IMV Controllability Troubleshooting"(2)
Stick Lowering Check Valve (SLCV) is malfunctioning Refer to Troubleshooting, "Relief Valve (Line) - Functional Test"
Stick Head End (HE) relief valve failure
SLCV pilot pressure is low or zero Refer to Testing and Adjusting, KENR9615, "Relief Valve (Pilot) - Test and Adjust"
Pilot relief valve is malfunctioning Refer to Testing and Adjusting, KENR9615, "Relief Valve (Pilot) - Test and Adjust"
Electronics/Harness/Solenoids Stick PCHE Proportional Hydraulic Modulating Valve (PHMV) is malfunctioning Refer to Troubleshooting, "IMV Calibration - Functional Test"(1)
Refer to Troubleshooting, "IMV Controllability Troubleshooting"(2)
Stick PCRE PHMV is malfunctioning
Stick CTRE PHMV is malfunctioning
Idler pump bypass PHMV is malfunctioning Refer to Troubleshooting, "Bypass Valve (ACS Valve) - Functional Test"
Drive pump bypass PHMV is malfunctioning
Stick DRV solenoid is malfunctioning(3) Refer to Troubleshooting, "Drift Reduction Valve - Functional Test"
The energize circuit of the stick Rod End (RE) DRV solenoid is shorted to ground(3)
SLCV solenoid is malfunctioning Refer to appropriate diagnostic code troubleshooting procedure
The ECM is malfunctioning. A failure of the ECM is unlikely Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with Caterpillar. This consultation may effect repair time. Follow the procedure in Troubleshooting, "ECM - Replace" to replace the ECM
Software Idler pump bypass calibration is incorrect Refer to Troubleshooting, "Bypass Valve (ACS Valve) - Functional Test"
Drive pump bypass calibration is incorrect
Stick PCHE PHMV cracking current is incorrect Refer to Troubleshooting, "IMV Calibration - Functional Test"(1)
Stick PCRE PHMV cracking current is incorrect
Stick CTRE PHMV cracking current is incorrect Refer to Troubleshooting, "IMV Calibration - Functional Test"(1)
Stick PCHE PHMV slope is incorrect
Stick PCRE PHMV slope is incorrect Refer to Troubleshooting, "IMV Calibration - Functional Test"(1)
Stick CTRE PHMV slope is incorrect
Combiner calibration incorrect Refer to Troubleshooting, "Flow Combiner Valve - Functional Test"
Pump/Motor/Tank Front or Rear pump fails to stroke up Refer to Testing and Adjusting, KENR9615, "Pump Flow Measurement"
Engine Low engine speed Refer to Troubleshooting, "Hydraulic Power - Functional Test"
(1) Denotes actions that should be completed first in the troubleshooting sequence.
(2) Denotes Functional Tests that should be considered as a last resort in the troubleshooting process.
(3) Refer to appropriate diagnostic code troubleshooting procedure