4.1 Headlamps, Fog Lamps, Cornering Lamps & DRLs

Apply each forward-lighting page separately

“Forward lamp” is not a single category. Identify whether a unit is a dipped beam, main beam/driving lamp, front fog lamp, cornering lamp, daytime running lamp (DRL), or a combined unit, then use its page.

Headlamp equipment and condition

A vehicle other than class LE generally requires one pair of dipped-beam headlamps; class LE generally requires one. The page controls the permitted number of dipped and main beams and contains date-specific exceptions. Lamps in a pair must be paired and, for retrofits, fitted symmetrically and as far toward each side as practicable.

Reject a lamp that is insecure or obscured, has large droplets/runs/puddles of moisture, has a missing or breached lens admitting dirt or moisture, or has deterioration reducing output. A readily removable non-clear cover is removed for inspection.

When operated, headlamp light must be substantially white or amber, steady, approximately matched within a pair, and bright enough for its purpose. An LED array fails where fewer than 75% of its sources operate.

Beam pattern and aim

With the road wheels straight ahead and any driver-adjustable levelling set to its highest position, inspect dipped beam. Reject an unfocused, reduced, or altered pattern; maximum intensity projected to the right; or aim that no longer permits the lamp to illuminate the road at least 50 m ahead. Alignment must follow the lamp or vehicle manufacturer or VIRM Table 4-1-1. Do not impose a generic 1%, 1.5%, or 2% cutoff on every lamp.

Main beam must operate within the permitted lamp count, must not project right of the vehicle centreline or above horizontal, and must be switchable to dipped beam or off from the driver’s seat. A main-beam warning device must work if fitted as original equipment; there is no blanket “post-1991 blue telltale” rule on this page.

Light-source changes

Reject a headlamp retrofitted with a source type not specified by the vehicle or lamp manufacturer—for example, an HID or LED bulb placed in a halogen headlamp. A bright-looking cutoff is not proof of compliance. Check the source, housing marking, output, pattern, and modification clause together.

Fog, cornering, and daytime running lamps

Open pages 4-2 through 4-4 for these units. A fog lamp must meet its permitted number, position, colour, control, and performance rules. A cornering lamp is designed to illuminate the direction of turn and must operate in the permitted way rather than function as an extra headlamp. A DRL must meet its colour, pairing, visibility, and switching requirements; its interaction with indicators or position lamps may involve temporary dimming or extinguishing when designed that way.

For every permitted lamp, defective operation does not become harmless merely because the lamp is optional. The page will state whether it must be made compliant, disabled, or removed.

Inspection sequence

1. Identify every forward-facing lamp and whether it is OE or retrofitted.
2. Check number, pairing, mounting, lens, reflector, moisture, and obstruction.
3. Operate dipped and main beam and observe colour, equality, warning device, and switching.
4. Check beam pattern and aim using manufacturer data or the VIRM table.
5. Inspect the fitted source type; reject incompatible HID/LED conversions.
6. Test fog, cornering, and DRL functions on their dedicated pages.
7. Recheck visibility where bodywork or accessories have changed lamp angles.

Scenario

A pair of halogen housings contains plug-in LED bulbs. Output is bright and the beam appears near the tester marks. It still fails because the retrofitted source type is not specified for the housing; apparent aim does not override the modification reason.

Combined and adaptive units

A modern housing may combine dipped beam, main beam, DRL, position lamp, indicator and cornering functions. Test each separately and observe how the manufacturer intentionally dims or switches adjacent functions. A fault in one function does not automatically describe the others, but damage or moisture can affect the whole unit.

Adaptive or self-levelling systems still must produce a compliant beam in the prescribed test state. Allow the normal start-up levelling cycle to finish, set driver controls as the note requires, and use manufacturer information when a special mode is needed. Do not condemn normal beam movement or excuse a persistent unfocused/right-projecting pattern by calling it adaptive.