Rule of thumb for warning lights and messages

Welcome to our first Tech Tips.

So I thought we would start with a good general rule of thumb about the dreaded warning lights. We often get calls from our customers that a warning light has come on. They often want to know what it means and what they can do about it. This article will hopefully make some of them easier for you to work out what to do, more importantly that you don’t do any further damage, by being aware of what the dash is trying to tell you.

Dash Lights

Hopefully your dash doesn’t look like the one above.

So to the guts of it and it is quite simple,

RED = Stop the car and engine as soon as it is safe to do so.

ORANGE/YELLOW = Get it checked by experienced and/or qualified person as soon as you’re able

GREEN/BLUE = Notification that something is on

FLASHING = Get it checked by experienced and/or qualified person as soon as you’re able

Now these are not hard and fast rules, but if you’re not sure I would stick to them until you can find out or contact someone about them. You’re always welcome to give us a call if you need to know what a light does and if you can keep driving.

As I mentioned, these are not hard and fast rules and the dash from a Discovery S2 above shows a good example of this.


These lights are the Centre diff lock light and Traction control lights. Both these lights come on whenever the diff lock and traction control are actuated/on. They are also orange. So they go against my rule of thumb, as such you don’t need to get them looked at if they are on by themselves. Just make sure diff lock is off if you’re on the road and the TC should turn off in most on road driving.

So if I get a light what can I do about it? Well that depends on what the light is and what model you have. In future articles we will go through each models warning lights and message centre warnings to give you a better understanding of what they mean for your model.

For now, best idea is to stop, switch the car off for a minute and start it back up. Most systems will do a self check and if the fault isn’t present it will turn off the light and usually keep the fault stored so we can read it.

Something we hear quite often is “I was told to disconnect the battery to clear the fault”. Now again this works for some faults/models and it also, in some models, can cause more faults. The later vehicles you can do a “hard reset” of the ECUs, but again this may cause more faults. Of course more faults that are not “real” fault can be harder for us to diagnose the original fault. So unless you have a good idea, what fault it is and how bad it is, I wouldn’t disconnect the battery.

Always remember each light will be listed in your owners manual and most models will give you a quick run down on what to do.

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