If your Sinoboom is screaming with a tilt alarm and locking out drive functions during transport, the machine is likely on too steep an incline. The sensor is doing its job. The correct procedure is not to bypass the sensor but to use the machine's transport mode or troubleshoot a potential faulty component.
Symptoms & Identification
- Audible Alarm & Function Lockout: The most common symptom. The machine beeps loudly and will not drive or lift.
- Active on Ramps: Alarm triggers when driving up a trailer ramp but stops once the machine is level on the deck. This is normal operation, not a fault.
- Active on Level Ground: Alarm triggers and functions are locked out while the machine is parked on a confirmed flat surface. This indicates a potential faulty sensor, wiring issue, or calibration problem.
- Fault Code 18: Many Sinoboom models will display this code on the control box screen, specifically indicating a tilt sensor circuit fault.
Tools Required
- Multimeter
- Metric Socket & Wrench Set (10mm - 17mm)
- Torque Wrench
- Wire Brush & Electrical Contact Cleaner
- Digital Level
Safety Warning
Chock the wheels and disconnect the negative battery terminal before inspecting or replacing any electrical components. The tilt sensor is a critical safety device. Bypassing it is a direct violation of ANSI/OSHA standards, voids the warranty, and creates a severe tip-over hazard.
The Technical Guide (Step-by-Step)
If the machine alarms on a legitimate slope, the solution is to find a more level loading area or reduce the ramp angle. If the alarm is active on flat ground, follow these diagnostic steps.
- Visually Inspect the Sensor: Locate the tilt sensor on the main chassis. Look for physical damage, cracked housing, loose mounting bolts, or a corroded wiring harness connector. A wobbly sensor will send false signals.
- Verify Level: Place a digital level directly on the chassis frame next to the sensor mounting point. Confirm the machine is truly level (less than 1°). This rules out the environment as the cause.
- Check Wiring Harness: Disconnect the harness from the sensor. Check for corrosion (green/white crust) on the pins. Clean with electrical contact cleaner. Check for any chafed or pinched wires leading back to the main controller.
- Test Sensor Voltage: Reconnect the battery. With the key on, carefully back-probe the sensor connector. You should see a reference voltage from the ECU (typically 5V or 12V, check your manual). No voltage indicates a problem upstream at the controller or in the harness.
- Replace the Sensor (If Necessary): If the sensor has voltage and the wiring is good, the sensor itself has likely failed.
- Disconnect the battery again.
- Unbolt and remove the old sensor.
- Clean the mounting surface on the chassis thoroughly.
- Install the new sensor in the exact same orientation.
- Torque the mounting bolts to the manufacturer's specification. Refer to your specific service manual for torque values—do not overtighten.
- Perform Mandatory Calibration: A new sensor MUST be calibrated. The machine's ECU needs to learn the new sensor's "level" position. This procedure is model-specific and requires a sequence of actions at the ground controls. Consult your Sinoboom service manual for the exact calibration steps. Skipping this will result in the same fault code returning.
Note: Components may vary by Gen 1 vs Gen 2 series. Verify with your parts manual.
The Part You Need
If your diagnostics confirm a failed tilt sensor, you need an OEM or OEM-compatible replacement. Waiting for a dealer to source this part from China can take weeks, leaving your machine down. China Lift Supply stocks Sinoboom tilt sensors and compatible universal versions in the United States to avoid the typical 6-week dealer lead time.
Can't wait 6 weeks for this part? We have it on the shelf in Kansas. Check the price and availability here: https://www.chinaliftsupply.com.
