Summary
The objective of this procedure is to show you how to check an automotive security system on a vehicle. Transponders are designed to cope with normal operating stresses. If the transponder is not working properly you might need to replace its battery.
Part 1. Preparation and safety
Objective
- Check an automotive security system on a vehicle.

Personal safety
Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:
- Work clothing - such as coveralls and steel-capped footwear
- Eye protection - such as safety glasses and face masks
- Ear protection - such as earmuffs and earplugs
- Hand protection - such as rubber gloves and barrier cream
- Respiratory equipment - such as face masks and valved respirators
If you are not certain what is appropriate or required, ask your supervisor.
Safety check
- Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.
Points to note
- Some systems are movement sensitive, so it is difficult to try to start the car from the inside. Your movement will set the alarm off.
- Some vehicle security transponders may not operate in some environments. This may be because there is strong electromagnetic interference in the area.

- If a transponder does not seem to operate verify that it belongs to the vehicle you are attempting to unlock. It may be that a busy service advisor has mislabeled the key and transponder from another vehicle.
- Transponders are designed to cope with normal operating stresses. Do not drop them into liquid or subject them to extreme heat or force.
Part 2: Step-by-step instruction
- Set the security system
This section deals with vehicle security and alarms. When the system is armed, an LED type light usually blinks on the dash. In some cases you will also hear an audible tone. Sit inside the vehicle with the doors shut. Lock the doors and activate the security system. This is usually done with a transponder. The transponder that turns the security system on and off is usually a small battery-powered device attached to the key ring, or built in to the ignition key itself.
- Test the security system
Start the engine. If the security system immobilizes the engine then this action should not be possible. If the security system is an audible alarm, it should now go off. If the security system works properly, move the vehicle to a different location - for instance, outside the workshop - and test it again. A transponder can suffer from electronic interference and may work better in some locations than others.
- Check transponder operation
If the security test fails, check whether or not the transponder has power and is operating correctly. If it operates the door locks as well as the security system, locking and unlocking the vehicle will confirm that the transponder is working.
- Replace transponder battery
If the transponder is not working properly you might need to replace its battery. To do this, you will need to refer to the specific manufacturers specifications for changing the battery to re-test the unit.
- Action on failure
If either the security system or the transponder is not working, you should report it to your supervisor.