According to a TÜV Süd investigation, every fourth vehicle has “significant defects” in the main inspection (HU). The ADAC warns: 22% fall through the HU every year. The most common reason is a lack of lighting. We therefore recommend taking part in the free light test in October.
If such a finding is found, the new sticker will be refused and the car will have to be presented again. Of course, this results in additional costs and a not inconsiderable loss of time – which can be avoided in most cases. However, if you take a few things into account in advance, you can almost always prevent such an unwelcome result.
The following before the main inspection test
- Have the registration certificate part 1 ready
- Bring documents for the emission test (AU) with you
- Check the indicator lights in the cockpit
- Check lights (all lamps) and horn
- Check the functionality of the warning triangle, safety vest and first-aid material and pay attention to the expiry date
- Do the tires still have 1.6 millimeters of tread depth?
- Clean and tidy vehicle
- Does the windscreen washer system have enough water / antifreeze?
- Have papers ready for changes/conversions (wheels, exhaust, etc.).
Check important assemblies yourself
Because the components checked during the main inspection can also be inspected by any driver with little technical understanding. First of all, the lighting system should be checked: Of course, the low and high beams must work, the same applies to the signaling devices such as turn signals and brake lights. The correct adjustment of the headlights is also often criticized, but a check in the garage at home is hardly possible. If the setting is not correct during the test, readjustment on site is usually uncomplicated.
The most important test criteria of the main inspection
- Brake and tire condition
- Functionality of the lighting system
- Excessive undercarriage clearance check
- Check the underbody for corrosion
- Control of the electrical assistance systems
You should start by checking the tires because other types of damage can also be discovered here. It is important to ensure that the profile corresponds to the legal 1.6 millimeters and is worn evenly. Uneven wear points to defects in the chassis, which should be rectified as quickly as possible in your own interest. The age of the tires, on the other hand, is not a test criterion, but the nature of the rubber compound is: If the tire is visibly porous, the sticker can be refused. The condition of the brakes is also relevant to safety. A testing facility is required for the braking effect; as long as the brake pads and discs are not worn out, no surprising results need to be expected here. The thickness of the discs and pads can be checked with the handlebars turned to their maximum. It is usually not necessary to measure precisely. There is a gap in the middle of the brake pads, which divides the actual pad into two halves. In any case, this gap must still be visible. The brake disc, on the other hand, forms an edge on the outer edge that becomes more and more apparent as wear progresses. It may be felt, but not too pronounced – if in doubt, it should be measured.
The rust returns
If possible, the underbody should also be checked. Unfortunately, rust, which was the main enemy of cars for many years, has returned: many manufacturers have saved on corrosion protection in recent years, so that rotting underbodies are an issue again, even in relatively young vehicles. Load-bearing parts such as the side skirts should therefore always be rust-free. The same applies to the brake lines and the chassis. In addition, there should be a check for oil loss: If it drips under the car, the new sticker will be refused in any case. Slight leaks, on the other hand, are usually accepted. A final look falls on the dashboard: the lamps for ESP or ABS should go out after the start, which signals that the systems are functional.
If you have checked all these points without finding any defects, you don’t have to fear a fine and can drive to the nearest workshop for the main and exhaust gas inspection with peace of mind.
How to pass the main examination
It’s often just the little things that stand in the way of the new inspection sticker. Everyone can easily check whether the lights or the horn are working and have them repaired if necessary. This saves time and money during the examination and you can avoid a follow-up examination.
Are all papers available?
If you go to the test hall, you have to have the vehicle registration document (registration certificate part 1) ready. It is best to place them on the dashboard so that you do not have to search for them for a long time. In the case of a follow-up examination, the report from the previous HU is also required, otherwise a complete HU is required again.
Submit proof of AU and ABE certificate
Was the emissions test previously carried out in the workshop, the AU proof is also required. However, this one is allowed not older than two months be. If there are papers on vehicle changes, for example on special wheels, tuning or silencers, you should have them ready with the other documents. If a mandatory report is missing, this is a significant deficiency at the HU.
Check indicator lights
The indicator lights in the cockpit are also worth a look. If the lights for ABS, ESP, airbags or other safety components light up continuously, this is an indication of a malfunction. In plain language: There is no badge.
Lighting – one of the most common shortcomings
One of the most frequently criticized assemblies at the HU is the lighting. Whether the headlights, brake lights and indicators are working can be easily checked on the garage wall or with the help of a passenger. The horn can be tested just as easily.
Prepare accessories
The “HU classics” warning triangle, safety vest and first-aid material should also be clearly visible. If they are missing or unusable, there is a risk of a minor defect. Things to note here: this First Aid Material must comply with DIN 13164 and at the latest renewed after five years will. The expiry date is stated on the case.
1.6 millimeter tire profile
The tires must still have at least 1.6 millimeters of tread depth. The windshield washer system also needs enough water.
Last but not least, a cleaned car makes a good impression. Since the interface for on-board diagnostics is often in the area under the ashtray, the inspector is happy when there is cleanliness here.
The times when drivers had to be afraid of the HU are long gone. Our job at the HU is to make sure that people get through traffic safely, and we want to make that as pleasant as possible for them.
Where can I carry out a general inspection?
Various service providers offer the implementation of the HU. The test center must be state-recognized. In addition to the independent test centers, you can also simply make an appointment at your garage. The test is then carried out by an authorized inspector who visits the workshop regularly. This saves the long journey to the test center.
Here is a list of independent test centers & workshop portals: