Car broke down on the road? Safe steps, in order, before you call a mechanic

It is Friday afternoon and the main road is packed. Suddenly the engine stutters, loses power, and the car comes to a stop in the left lane. Drivers behind you start honking. In a moment like this, most people's first instinct is to crank the engine again and again, or to open the hood and look for the cause. Both can make things worse.

This guide sets out the safe steps in order, from making sure you are safe to getting the details ready for the mechanic or the tow crew. The order matters: mistakes in the first few minutes often cost more than the fault that stopped the car.

If the car can still move, steer it onto the shoulder or somewhere out of the flow of traffic. Switch on the hazard lights straight away. Under Indonesia's Road Traffic and Transport Law (UU 22/2009), every motorist must use a warning triangle, hazard warning lights or another signal when stopping or parking on the road in an emergency.

If you smell gasoline, see smoke coming from the engine bay or see flames, do not try to do anything to the car: get out, move all passengers well away and call emergency services.

A warning triangle is not an optional extra. Under UU 22/2009, the minimum equipment for a vehicle with four or more wheels is seat belts, a spare tire, a warning triangle, a jack, a wheel wrench and a first aid kit. Drivers of vehicles without an enclosed body also need a helmet and a reflective vest. Set the triangle up behind the car so other drivers have time to steer around it. On toll roads, guidance quoted by Kompas likewise recommends pulling onto the shoulder, switching on the hazard lights and setting up the warning triangle while you wait for help.

Before your next trip, check that all of this equipment is in the trunk and in working order.

Before you try to restart the engine, look at the lights on the instrument panel and think back to the last symptoms before the engine died. Some lights decide the next step on their own:

• Engine temperature light on or temperature needle high: the engine is overheating. Switch off the engine and let it cool down. Do not open the radiator cap or the reserve tank while the engine is hot: the system is under pressure and can spray scalding fluid.
• Red oil pressure light: the engine is no longer holding oil pressure. Do not restart it: an engine without oil pressure can be damaged in under a minute.
• Battery light on before the engine died: the charging system has probably stopped working, for example because of the alternator or the drive belt. The car then ran on what was left in the battery until it went flat.
• Check engine light flashing before the engine died: this points to a severe misfire. Do not make the engine work hard.

Make a note of every light that is on. It will be very useful to the mechanic who comes out.

If the car died while or after driving through deep water, different rules apply: do not start the engine, even if the water has receded and the car looks fine. Water that enters the combustion chamber cannot be compressed like air. If the engine is started, that water can bend the connecting rods. This condition is known as water hammer or hydrolock. Water can also enter the lubrication system and mix with the oil. Water around 50 cm deep or more is already enough to risk it.

Water can enter the engine through several openings, for example the exhaust or the air filter. To judge the risk, look for the high-water mark in the engine bay: if the water line is above the transmission housing, water may have got into the engine.

What to do: do not turn the key to start the engine, and disconnect the battery cable if you can, to prevent a short circuit. If the current is not dangerous, the car can be pushed to safer ground; if the current is strong or the water is too high, do not attempt it. Check the oil on the dipstick: oil that is cloudy or has turned brown means water has got into the engine. If so, do not start the engine; call emergency services or a tow truck to take the car to a workshop.

Components such as the spark plug, air filter, coil and alternator, along with the wiring and its connectors, are easily damaged by floodwater. The engine control module (ECU) is also very sensitive, so do not dismantle or check it yourself. If the car is not blocking traffic, it can stay where it is until help arrives; make sure no valuables are left inside.

On the toll road: call the Jasa Marga call center on 14080 or use the Travoy app, then follow the officers' instructions on towing and its cost. Officers head out once they have taken your report and confirmed where you are on the toll road, so have the toll section name and a nearby landmark ready before you call. Using the official service gives you clarity on both safety and rates.

On other roads: call a tow service or an emergency assistance provider you know. If the car is already somewhere safe and the cause may be simple, a mechanic can help work out whether it can still be driven or needs a tow.

• Exact location: the street name or toll section, kilometer marker, direction of travel and the nearest landmark.
• The car: make, model, year, manual or automatic transmission.
• What happened before it stopped: stuttering, a particular noise, a smell, smoke, or a sudden cut-out.
• Warning lights: from your notes in step 3.
• What it does now: the engine will not crank at all, cranks but will not start, or runs but the car will not move.
• Recent history: just drove through a flood, just refueled, just had a service.

Complete details help the mechanic bring the right tools and spare parts, and help the tow crew send a suitable truck.

Agree on where the car is going and what the tow will cost before it is loaded up. Give your notes on the symptoms and warning lights to the mechanic or crew who arrive. Tell them if the car has just been through floodwater, because that changes what can and cannot be done to the engine.

• Restarting the engine over and over while the red oil pressure light is on, or after the car has been submerged.
• Opening the radiator cap while the engine is still hot.
• Standing or working on the traffic side of the car without a warning sign set up.
• Agreeing to a tow before the destination and the cost are clear.
• Leaving passengers in the car when you can smell gasoline or see smoke.

A mechanic is most useful when the car is already somewhere safe, has not been submerged, is not smoking, and the cause may be simple, such as a weak battery or a minor electrical fault. If the car has been submerged, is leaking gasoline, has the oil pressure light on or is stuck in a dangerous lane, put towing and your passengers' safety first.