The first thing to do is check the fluid level in the transmission. Problems like this are often caused by a low fluid level, so that’s where to start. The problem then is that the Captiva’s transmission doesn’t have a conventional dipstick, so the level is checked by getting the vehicle up to operating temperature and then removing the fill bung (on the transmission next to the left-hand driveshaft. Obviously, you need to car off the ground to do this.

If a little fluid drips out of the fill bung when you remove it, the fluid level is correct. If not, you need to add fluid until it does start to drip back out. If the transmission is low on fluid, you’re also dealing with a leak, because this is a sealed system and should not require top-ups.

Don’t be tempted to continue driving the vehicle as it is, as the fluid not only provides the drive for the transmission, it also lubricates the moving parts. So operating it with a low fluid level can cause permanent damage to the unit.

It all depends on what you mean by coming on and off. The air-bag light should come on briefly every time you start the engine, but should then go out after a few seconds. This just confirms the car is checking the air-bag system for proper operation and is perfectly normal.

If, however, the air-bag light is lighting up randomly as you drive down the road, then you need to have the car scanned to see what the problem is. In this case it could easily suggest that there's a problem with this critical safety system, so don't ignore it.

In many cases, this (usually) four-digit security code will be written down somewhere inside the owner's manual or the car's service manual. Both these documents should be stored in the glovebox. Another popular way to store the code was to write it on the back of the business card of the salesperson who sold the car new, and attach that to the owner's handbook somewhere.

Often, however, these books go AWOL, at which point you need to contact a Holden workshop with the car's VIN. From there, you should be able to check Holden's records and find the security code. You may have to provide proof of ownership of the vehicle, however.

If that fails, sometimes you can do an internet search on a specialist website, but to do that, you'll need to know the serial number of the stereo unit. Usually, that involves removing the unit from the car, a process that can range from very easy to incredibly difficult.