BODY 1U2177 - Caterpillar

Table 1
Related Components: Possible Causes: Recommended Action:
Valve/Lines Low pilot pressure Refer to Testing and Adjusting, KENR9615, "Relief Valve (Pilot) - Test and Adjust"
Drift Reduction Valve (DRV) poppet is malfunctioning Refer to Troubleshooting, "Drift Reduction Valve - Functional Test"
Boom Cylinder to Tank Head End (CTHE) spool is malfunctioning Refer to Troubleshooting, "IMV Calibration - Functional Test"(1)
Refer to Troubleshooting, "IMV Controllability Troubleshooting"(2)
Boom Lowering Check Valve (BLCV) is malfunctioning Refer to Troubleshooting, "Relief Valve (Line) - Functional Test"(1)
Pilot relief valve failure Refer to Testing and Adjusting, KENR9615, "Relief Valve (Pilot) - Test and Adjust"
Electronics/Harness/Solenoids Boom/Bucket joystick is malfunctioning Refer to Troubleshooting, "Joystick - Functional Test"(1)
Boom CTHE PHMV is malfunctioning Refer to Troubleshooting, "IMV Calibration - Functional Test"(1)
Refer to Troubleshooting, "IMV Controllability Troubleshooting"(2)
The energize circuit of the Boom CTHE PHMV is shorted to ground 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
DRV solenoid is malfunctioning(3) Refer to Troubleshooting, "Drift Reduction Valve - Functional Test"
The energize circuit of the DRV solenoid is shorted to ground(3)
BLCV solenoid is malfunctioning Refer to appropriate diagnostic code troubleshooting procedure
Software Slope value is 0mm/A or near 0mm/A Refer to Troubleshooting, "IMV Calibration - Functional Test"
Cracking calibration value is 0mA or near 0mA
BLCV installation status setting is not correct Change the BLCV installation status to "Installed" through Monitor or Cat ET
(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