The driver needs to understand when or if a vehicle can be used should a warning lamp be illuminated either at the start of a shift or during a shift. Also, what action should immediately be taken should this happen?
Drivers and operators must be aware of the implications of using a vehicle when a dashboard ‘Malfunction indicator lamps’ (MIL) is illuminated.
Company reporting procedures should already be in place regarding defect reporting which must include warning lamps. Some warning lamps are there to provide information/assistance to the driver. Any issues regarding dashboard warning lamps should be reported on the driver’s daily walk around check sheet or electronic device and actioned before the vehicle’s journey commences.
Most manufacturers’ warning lamp systems work on a fit and forget basis – the system will check itself and tell the driver if there is a problem. When the ignition is switched on, a ‘system check’ is undertaken. This usually results in all the warning lamps illuminating for a few seconds and then extinguishing, unless a system is active (eg park brake applied or washer fluid low) or the system is faulty.
Manufacturers have dashboard warning lamps with various symbols. Although they may differ slightly between manufacturers there is a general theme/guidance.
Always refer to the vehicle’s own handbook or manufacturer’s guidance regarding vehicle specific dashboard warning lamps and their meanings. Below is a small selection as general examples:
Anti-Lock Braking System (ABS)
One of the most common and well-known ones is the Anti-Lock Braking system warning lamp. Where a red ABS warning lamp is displayed, the vehicle should not be driven until the fault is rectified. Where a yellow ABS lamp is illuminated during a journey this must be assessed before continuing with the journey. Where an ABS lamp is yellow but a secondary red (STOP!) MIL is illuminated, then this should be treated as red.
If we refer to the DVSA Categorisation of vehicle defects concerning roadside enforcement, IM 38 Service brake operation states:
“Where a vehicle displays a yellow ABS MIL (Malfunction Indicator Lamp) and there is evidence the ABS system operated correctly at the beginning of the current journey (24-hour period), or a journey directly to a place where the ABS is to undergo repair, the issue of an inspection notice would be the appropriate course of action.”
Logistics UK has also produced a briefing note on this subject which contains a useful flow chart on the procedure to follow should this fault occur during your journey.
Engine/Emissions
For engine or emissions warning lamps these can attract a roadside prohibition, especially where emissions control systems are concerned and there is evidence of a fault, the system has been tampered with or there is evidence of no re agent in the tank. Where we refer to the DVSA Categorisation of vehicle defects Concerning roadside enforcement IM 5 exhaust emissions states:
Prohibition action should only be taken where there is evidence that a fault is clearly identified. Where it is not clear the MIL is indicating a fault with the system, inspection notice action should be taken. The reagent tank must be empty to justify prohibition action.
Diesel Particulate Filter Warning
This type of warning lamp may stay illuminated when passive regeneration has failed, warning the driver that active regeneration needs to take place as the filter is becoming blocked. This is usually due to the vehicle only making short local journeys allowing a build-up of soot in the filter. If the warning is ignored and regeneration is not carried out this can have detrimental effect on the filter and lead to more expensive repairs. At the very least the vehicle could go into reduced power mode and need to be taken to the dealer/maintenance provider for the fault to be cleared, which could include manual regeneration or more to clear the filter.
Brake Pad Warning
This symbol when illuminated in yellow would usually indicate that the brake disc pads are worn close to their limit. Although it may be safe to drive the vehicle, advice should be sought immediately before starting or continuing with a journey should this dashboard symbol illuminate.
Advance Driver Assistance Systems (ADAS)
These systems are becoming increasingly more common on today’s vehicles including modern trucks and trailers. It is important that the driver understands the warning lamps related to such systems.
Some ADAS systems will, following a driver deactivation, automatically reactivate themselves once the ignition is switched off. When the driver switches the ignition on again the system should be fully operational.
Tyre Pressure Monitoring System (TPMS)
This is another system that is becoming more common. When illuminated this would indicate low tyre pressure, warning the driver of a possible issue. Where the system is interrogated it will usually indicate the position of the tyre that is underinflated. This should be acted upon immediately as this could save further issues due to the tyre being so underinflated that it overheats, disintegrates and causes further damage or a more serious incident.
Power Steering Warning Lamp
When we look at electronic power steering (EPS) the Categorisation of vehicle defects IM54 steering mechanism states:
Malfunction indicator lamp (MIL) indicates any kind of system failure-Delayed Prohibition.
This is only a very small selection of the array of warning lamps a driver is confronted with in the modern trucks of today.
We cannot emphasise enough that whenever a driver is given a new vehicle to use for the first time, part of the handover should be some form of familiarisation training (this could form part of your company policy and also included within any induction training for new staff). This is particularly important in today’s technological world to ensure the driver and operator can remain as compliant as possible.
*www.logistics.org.uk/mac
