Introduction
This manual provides essential information for the safe and effective operation, maintenance, and troubleshooting of your Bosch Professional 18V System GSR 18V-90 C Cordless Drill. This powerful tool is designed for professional use, offering high performance for drilling and driving applications. It includes 2 x PROcore 4.0 Ah batteries, a Bluetooth Low Energy GCY 4 module, a GAL 18V-40 charger, and an L-BOXX for convenient storage and transport.
Please read all safety warnings and instructions carefully before using the product. Keep this manual for future reference.
Safety Instructions
Always observe the following fundamental safety precautions when operating power tools:
- Work Area Safety: Keep the work area clean and well-lit. Cluttered or dark areas invite accidents. Do not operate power tools in explosive atmospheres, such as in the presence of flammable liquids, gases, or dust.
- Electrical Safety: Avoid body contact with earthed or grounded surfaces such as pipes, radiators, ranges, and refrigerators. There is an increased risk of electric shock if your body is earthed or grounded.
- Personal Safety: Always wear eye protection. Use hearing protection when operating the tool for extended periods. Wear a dust mask if operations create dust. Dress properly; do not wear loose clothing or jewelry. Keep hair, clothing, and gloves away from moving parts.
- Tool Use and Care: Do not force the power tool. Use the correct power tool for your application. Disconnect the plug from the power source and/or remove the battery pack from the power tool before making any adjustments, changing accessories, or storing power tools.
- Battery Tool Use and Care: Recharge only with the charger specified by the manufacturer. Use power tools only with specifically designated battery packs.
Components Overview
The Bosch Professional GSR 18V-90 C Cordless Drill comes with several key components:
- Cordless Drill (GSR 18V-90 C)
- 2 x PROcore 4.0 Ah Lithium-Ion Batteries
- GAL 18V-40 Battery Charger
- Bluetooth Low Energy GCY 4 Module
- L-BOXX Carrying Case

Figure 1: The Bosch Professional GSR 18V-90 C Cordless Drill, showing the main unit with a PROcore battery attached. This image illustrates the compact design and key features of the drill.
Setup
1. Charging the Battery
- Connect the GAL 18V-40 charger to a suitable power outlet.
- Insert the PROcore 4.0 Ah battery into the charger. Ensure it clicks into place.
- The charging indicator light on the charger will illuminate, indicating the charging status. A full charge typically takes approximately 60 minutes for a 4.0 Ah battery.
- Once fully charged, remove the battery from the charger.
2. Installing the Battery
- Align the charged battery with the base of the drill handle.
- Slide the battery into the drill until it locks securely into position. Ensure it is fully seated to prevent accidental detachment during operation.
3. Installing/Removing Drill Bits or Screwdriver Bits
- To Install: Rotate the chuck counter-clockwise until the jaws are open wide enough to insert the bit. Insert the bit fully into the chuck. Rotate the chuck clockwise to tighten the jaws securely around the bit. For best results, ensure the bit is centered.
- To Remove: Rotate the chuck counter-clockwise to loosen the jaws and remove the bit.
4. Installing the Bluetooth Low Energy GCY 4 Module (Optional)
The GCY 4 module allows for connectivity with the Bosch Toolbox App for personalized settings and tool information. Refer to the separate instructions provided with the GCY 4 module for detailed installation and pairing procedures.
Operating the Drill
1. Powering On/Off and Speed Control
- The drill is activated by pressing the trigger switch. The further the trigger is pressed, the higher the rotational speed.
- Release the trigger switch to turn off the drill.
- The drill features a variable speed function, allowing precise control over the rotational speed based on trigger pressure.
2. Direction of Rotation
The forward/reverse switch located above the trigger controls the direction of rotation. Push the switch to the left for forward rotation (for drilling and driving screws) and to the right for reverse rotation (for removing screws or freeing jammed bits).
3. Torque Settings
The torque setting ring, located behind the chuck, allows you to adjust the amount of torque applied. This is crucial for driving screws to prevent overtightening or stripping. Higher numbers indicate higher torque. For drilling, set the ring to the drill symbol for maximum power.
4. Kickback Control
The GSR 18V-90 C features an integrated Kickback Control function. In the event of sudden and unpredictable rotation of the power tool around the drilling axis (e.g., when the drill bit jams), the integrated sensor detects this and switches off the motor within a fraction of a second to reduce the risk of injury.

Figure 2: A user demonstrating the Bosch Professional GSR 18V-90 C Cordless Drill in action, drilling into a wooden surface. This highlights the tool's ergonomic design and practical application.
Maintenance
1. Cleaning
- Keep the ventilation slots of the power tool clean to ensure proper motor cooling.
- Regularly clean the chuck jaws to ensure proper gripping of bits.
- Use a soft brush or compressed air to remove dust and debris from the tool. Do not use water or chemical cleaning agents.
2. Battery Care
- Store batteries in a cool, dry place, away from direct sunlight and extreme temperatures.
- Do not store batteries in a discharged state for extended periods. Recharge them periodically if not in use.
- Protect batteries from impact and moisture.
3. Storage
When not in use, store the drill, batteries, and charger in the L-BOXX carrying case in a secure, dry place, out of reach of children.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Drill does not start. | Battery not inserted correctly or discharged. | Ensure battery is fully seated. Charge the battery. |
| Reduced power or speed. | Battery low or incorrect torque setting. | Recharge battery. Adjust torque setting to a higher value or drill mode. |
| Bit slips in chuck. | Chuck not tightened sufficiently or bit shank is dirty/damaged. | Tighten chuck firmly. Clean or replace the bit. |
| Overheating. | Continuous heavy use or blocked ventilation slots. | Allow the tool to cool down. Clear any obstructions from ventilation slots. |
Specifications
Technical data for the Bosch Professional GSR 18V-90 C Cordless Drill:

Figure 3: Dimensional drawing of the Bosch Professional GSR 18V-90 C Cordless Drill, indicating its length (163 mm), height (210 mm), and width (77 mm) without the battery.
| Feature | Detail |
|---|---|
| Model Number | 06019K6005 |
| Brand | Bosch Professional |
| Power Source | Battery Powered (18V Lithium Ion) |
| Maximum Rotational Speed | 2100 RPM |
| Voltage | 18 Volts |
| Amperage (Battery) | 4 Amps (PROcore 4.0 Ah) |
| Maximum Chuck Size | 13 Millimeters |
| Material | Metal (chuck) |
| Maximum Torque | 64 Newton Meters |
| Item Weight (without battery) | 1.52 Kilograms (approx. 3.34 pounds) |
| Maximum Power | 850 Watts |
| Drilling Capacity (Wood) | 25 Millimeters |
| Drilling Capacity (Metal) | 13 Millimeters |
| Product Dimensions (L x W x H) | 17.52 x 14.17 x 5.91 inches (packaged) |
| Special Features | Variable Speed, Kickback Control, Brushless Motor |
| Included Components | 2 x PROcore 4.0 Ah Batteries, Bluetooth Low Energy GCY 4 Module, GAL 18V-40 Charger, L-BOXX |
Warranty and Support
For warranty information, service, or technical support, please refer to the documentation provided with your purchase or visit the official Bosch Professional website. Ensure you have your product model number (GSR 18V-90 C) and part number (06019K6005) available when contacting support.
You can typically find more information and contact details on the official Bosch Professional website: www.bosch-professional.com





