Quick Answer
What is the Trimble GCS900?
See also: Trimble GNSS No Corrections Fix
See also: Trimble GNSS Fixed Solution Lost Fix
The Trimble GCS900 is a GPS-based machine control system for dozers and motor graders that automatically controls the blade to design grade. It achieves GPS accuracy of 25mm 3D with a connected base station.
Trimble GCS900 — Complete Specs, Manual & Guide
Category: Machine Control | Brand: Trimble | Model: GCS900
The Trimble GCS900 is Trimble's production machine control system designed for installation on dozers, motor graders, scrapers, and excavators. It uses GPS/GNSS positioning and onboard sensors (cross-slope, mainfall) to automatically drive hydraulic valves to maintain design grade, eliminating staking and dramatically reducing rework on earthworks projects.
Trimble GCS900 Full Specifications
| GPS accuracy (3D) | 25mm with base station |
| GPS update rate | 10Hz |
| GNSS support | GPS + GLONASS |
| Display | Trimble CB460 — 17cm (6.7") sunlight-readable color LCD |
| Cross-slope sensor | SNR940 dual-axis blade slope sensor |
| Valve control | Trimble MC-R3 valve driver |
| Communication | Trimble Kenai radio or direct cable |
| Operating voltage | 10-32VDC |
| Operating temperature | -30°C to +70°C |
| Connectivity | WLAN for design file transfer |
Accessories & Part Numbers
- SNR940 — Dual-axis blade slope sensor
- CB460 — Trimble machine control display (replacement)
- MC-R3 — Hydraulic valve driver module
- Trimble Kenai Radio — 900MHz spread-spectrum machine radio
- Trimble Business Center — Office design and reporting software
Error Codes Quick Reference
| E001 | GNSS signal lost — check antenna cable connections and sky view |
| E002 | Tilt sensor fault — inspect SNR940 cable and mounting |
| E003 | Valve driver fault — check MC-R3 power and hydraulic connection |
| E101 | No corrections — verify base station is broadcasting |
| E102 | Fixed solution lost — wait for RTK reacquisition or reposition |
Frequently Asked Questions — Trimble GCS900
What GPS accuracy does the Trimble GCS900 achieve?
The GCS900 achieves 25mm 3D accuracy (horizontal and vertical) when connected to a Trimble base station broadcasting RTK corrections. This is sufficient for finish grading to design tolerance on most earthworks projects.
What machines can the GCS900 be installed on?
The GCS900 is designed for installation on dozers (Cat D6-D11, Komatsu D61-D155), motor graders (Cat 12M-16M, Komatsu GD655), scrapers, and excavators. Machine-specific installation kits are available for each OEM.
Does the Trimble GCS900 require a base station?
Yes — the GCS900 requires RTK corrections from either a Trimble base station on the jobsite or a VRS/CORS network subscription to achieve 25mm accuracy. Without corrections, the system falls back to autonomous GPS with meter-level accuracy, which is insufficient for grade control.
How are design files loaded into the GCS900?
Design files are transferred to the CB460 display via USB flash drive or over the jobsite WLAN network. Trimble Business Center office software prepares design surfaces from DXF/LandXML files for transfer to the machine.
Can the GCS900 be moved between machines?
Yes — the GCS900 components (CB460 display, SNR940 sensor, GNSS antenna, MC-R3 valve driver) can be transferred between machines. Each machine requires its own mounting hardware and calibration. The GNSS antenna and sensor positions must be calibrated on each machine for accurate blade control.
Related models: Topcon 3D-MC2 Machine Control | Leica MC1 Machine Control
Track your GCS900 calibration dates, service history, and field verification records with Gradelog's Equipment Registry. Free to start at gradelog.com.
