Specifications

FCS1362 Page 51 of 74 © Nov 2010
It is particularly important to check for the correct operation of vehicle electronic systems while operating
installed transceiver units. EMC problems might be indicated either by warning lights on the vehicle’s
instrument cluster or by changes in direction indicator speed or engine RPM, both indicated and actual.
Although this applies especially to high-powered radio equipment the effects of cellular GSM, 3G and
TETRA transceivers must also be included.
Include the vehicle’s ICE system in the testing. If the installation has included fitting an audio mute
system ensure that any of the vehicle’s warning tones presented through the vehicle’s ICE are still
functioning when the radio equipment is in use. Inform the customer if this is not the case and take
expert advice if this problem needs to be resolved.
5.3.3. Checks on emergency service vehicles
The National Association of Police Fleet Managers (NAPFM) Design Guide for Vehicle Installations
should be consulted whenever tests are carried out on emergency service vehicles.
Prior to starting such work, a copy of this document should be obtained from the National Policing
Improvements Agency (NPIA) Automotive and Equipment Section (AES) – see Appendix C.
5.3.4. Vehicle’s engine and ignition during testing
All tests should be carried out for the correct operation of all installed equipment with the engine running
at fast idle (approximately 1500 RPM) and with the vehicle stationary.
Suitable exhaust extraction must be used if the tests with the engine running are carried out inside a
building.
See section 5.3.6 for information on undertaking road testing.
5.3.5. Dealing with problems found in final testing
If the installed system causes interference to the normal operation of the vehicle the system shall be
deactivated until the system manufacturer advises suitable corrective action.
Although aftermarket equipment may have been tested against the relevant EMC specifications prior to
coming to the market it may still generate narrow and broadband emissions of sufficient amplitude to
cause interference to radio reception.
With analogue voice radios this interference may be heard as distortion, noise or whistling superimposed
on the incoming signal.
For digital voice or data services the effects of the interference are more difficult to ascertain and may
result in intermittent denial of service depending whether the vehicle is located within a good or poor
service coverage area.
Interference may be visible on the signal strength (RSSI) indicator on some radio terminals whilst the
service is being blocked. Such interference may be perceived as a loss in service or coverage by the
customer.
If any interference occurs then every effort should be made to locate and rectify any installation problem
that may be the cause. Section 4.2.1 may be beneficial in this respect.
If a problem is found and cannot be rectified, and it is suspected that the equipment or vehicle is out of
specification, then the appropriate manufacturer, agent or supplier should be consulted.
If after following the advice of the manufacturer, agent or supplier the problem with the vehicle still exists,
it should be noted and the customer must be advised.
Under no circumstances should an attempt be made to modify any device or system that is being
affected by EMI.
5.3.6. Road testing
Provided that the static post-installation tests have shown both equipment and vehicle to be operating
correctly then on-road testing of communications and other installed equipment is generally considered