What is Sany General Fault Code P922?

Fault Code P922 on Sany excavators indicates a Hydraulic Pump Solenoid Circuit Malfunction, specifically detecting an abnormal electrical signal or open/short circuit in the main pump control solenoid.

This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects voltage irregularities, current draw issues, or complete signal loss from the hydraulic pump's proportional solenoid valve. The solenoid regulates hydraulic flow and pressure by controlling pump displacement angle based on operator inputs and load requirements. When this circuit fails, the ECM cannot properly modulate hydraulic output, directly compromising machine performance and potentially causing the system to enter a protective derate mode. For Sany excavators—particularly used machines with extended operational hours—this code often signals electrical degradation rather than mechanical pump failure, making accurate diagnosis critical before expensive component replacement.

Common Symptoms

• Sudden loss of hydraulic power across all functions (boom, arm, bucket, swing)
• Intermittent or complete hydraulic system sluggishness, especially during combined movements
• Warning light illumination on the instrument cluster with possible audible alarm
• Machine enters limp mode with restricted engine RPM (typically limited to 1500-1800 RPM)
• Hydraulic functions may work normally at startup but deteriorate as operating temperature increases

Potential Causes

Electrical connector corrosion at the pump solenoid—extremely common in used excavators exposed to moisture, mud, and debris infiltration at the pump mounting area.

Wiring harness damage from rubbing against the pump housing or hydraulic lines, particularly where the harness routes along the main pump near the swing motor assembly (known wear point on Sany models).

Solenoid coil failure due to overheating, internal short circuits, or normal wear after 6,000+ operating hours.

ECM power supply issues including corroded ground connections at the controller or voltage drops from aging battery cables.

Hydraulic contamination causing the solenoid spool to stick, increasing electrical resistance beyond acceptable parameters.

How to Troubleshoot and Fix Code P922

Step 1: Visual Inspection Locate the main hydraulic pump solenoid (mounted on pump body, driver's side). Disconnect the electrical connector and inspect for pin corrosion, bent terminals, moisture intrusion, or oil contamination. Check the wiring harness for abrasion damage, particularly where it contacts metal surfaces. On used excavators, this is the most common failure point.

Step 2: Electrical Testing Using a digital multimeter, measure solenoid coil resistance between the two terminals. Specification typically ranges 10-25 ohms (consult service manual for exact values). Test harness continuity from the ECM connector to the solenoid plug—any reading above 2 ohms indicates wiring degradation. Check for short to ground by measuring resistance between each wire and chassis ground (should read infinite/OL).

Step 3: Voltage Supply Verification With ignition on, measure supply voltage at the solenoid connector—should read 12V or 24V depending on system. If voltage is absent, trace back to the ECM and check fuse integrity and relay operation.

Step 4: Solenoid Replacement or Harness Repair If resistance is out of specification or physical damage exists, replace the solenoid (OEM part recommended for reliability). If harness damage is found, repair with heat-shrink solder connections and reroute away from friction points. Clear codes using Sany diagnostic software and perform operational test under load.

Disclaimer: This guide provides general diagnostic procedures. Always consult the official Sany service manual for model-specific specifications. For complex electrical issues or if unfamiliar with high-voltage systems, seek assistance from a certified heavy equipment technician.