2008 Jeep Grand Cherokee 3 Litre Diesel, Dash Warning Lights Explained
Mark: Good morning. It's Mark Bossert here with the Pawlik Automotive podcast with Mr. Bernie Pawlik of Pawlik Automotive in Vancouver, 19 time winners of Best Auto Repair in Vancouver as voted by their customers. How you doing this morning, Bernie?
Bernie: Doing very well.
Mark: We're gonna talk about a little issue that we noticed earlier in one of our earlier podcasts where you brought up a dash warning light picture and there was a whole bunch of lights that I'd never seen before, and I went, what the heck are all these? You're gonna show us what the dash warning lights are on a 2008 Jeep Grand Cherokee. It's a diesel model. What was going on with these lights and what are they?
Bernie: Well, let's start first of all. I think we're gonna start an educational series on dash warning lights because a lot of people don't really understand them, and it's really important to understand what they mean because they can create a lot of stress if you don't know what they mean, or if you don't know what they mean, you can also make dumb decisions by ignoring them. We'll start with this Jeep and work our way through. The first place to start before I get into the picture is there's basically two major colours of warning lights. There’s amber lights and there's red ones. The red ones are lights to be taken seriously right now. Amber ones are okay, something's going on, and you need to get some service or something addressed down the road. You'll notice often a car check engine light, which is a pretty popular light on every car, is an amber light. When it comes on, it doesn't mean oh my God, you gotta pull over. The only time with a check engine light you need to be really concerned is when the light is blinking because that indicates a catalyst damaging engine misfire, and that essentially you can keep driving the car, but it's gonna cost you a lot more money if you keep driving it for too long. That's the only time that light should probably be red, but it doesn't. It's an amber light telling you there's something that needs to be serviced.
Mark: Amber and blinking.
Bernie: Amber and blinking. Yeah, amber and blinking is serious, but that's the only light that's kind of an anomaly.
Mark: Have you got a picture?
Bernie: I do, because yeah, that would really make this a lot more entertaining. Okay. Let's get in the picture of our Jeep. I'll just hide us out of the way here somewhere so we can actually see this warning light. When you turn the key on to start the vehicle, you'll normally get all of your warning lights coming on. Sometimes they'll just blink on for a second or two, and I realize one light I didn't capture on this, this is the Jeep diesel. There's one light that sits right here. It's a little yellow light that looks like a coil sitting sideways, and that is the glow plug warning light. That light's not on on this particular picture correct I guess it switched off kind of quickly. The glow plug warning light, by the way, will come on for a longer period of time when the engine's cold. You'll also notice if you own an old diesel vehicle, back a couple of decades, the warning light will stay on a lot longer than modern diesel. Some of them they'll just stay for, even cold, a second and then shut off. But the key with this light is you want to wait, when you turn the key on, you want to wait to start it til after that light goes out. The other thing, this is a diesel model. The only difference, and I actually went through a manual on the Jeep Grand Cherokee. The only difference between the dash on a gas and diesel model is in this spot here that I'm circling where the glow plug light is, this has a tow haul warning light that's basically with the automatic transmissions. That's basically an automatic transmission mode that's available.
There is also on some of them, a four wheel drive low warning light that does come on in this spot as well.
Let's go through some of these lights, and I'm gonna point out. There are a couple that are not illuminated in this picture as well, but let's start with the red lights. You have your brake light right here. Now, there's an I and a P. P is for parking brake. The I indicates a brake system issue. Normally when this light will come on is it either ... The key is once you start the engine, if these lights remain on, that's when it's a concern, or when you're driving and the light comes on. Generally the brake light will be on when you have the parking brake on. If you take the parking brake off, this light will go off. The I light, this is probably just one light that does two functions. A lot of cars are like that. That can often indicate there's low brake fluid in the brake master cylinder reservoir. If you have your parking brake off and the light's off, go check your brake fluid level because it could be low. Now, low brake fluid shouldn't happen. It's an indication of one of a couple things. It could be that the brakes are worn out, or nearly worn out, or that there's actually a leak in the brake fluid system. But you can top it up, put the light out, but you should go in for service and have it looked at.
This here is your seatbelt light. As long as your seatbelt, if you're sitting in the drivers seat, or you have a passenger and they're not buckled in, this warning light will come on.
This is the airbag system warning light. This will test the airbag system, and if all things are good, it sometimes takes a few seconds. Sometimes they blink a couple of times, depends on the vehicle, but on the Jeep, essentially the light will go out and if it's out, then your airbag system is all working fine.
Other red lights. This red light here on a Jeep is for the security system. It's just basically a round dot. Again, it'll go off when the vehicle's running. If it blinks or does anything weird, there's an issue with the security system. Something that will need to be repaired and fixed. But of course, it won't likely cause you any problem to drive the vehicle. It just indicates if you care about your security, it's important. But also there can be an issue with the security system where the vehicle won't start, so if that light stays on and won't start, that could be an issue. Again, you'll be taking it to a shop to get it fixed.
This is a warning light that's a throttle issue warning light. This is a pretty serious warning light on Jeeps. It's on gas motors as well as diesels, and the particular Jeep that kind of inspired us to do this, we had a couple of weeks ago with some intake manifold runner issue. While diesels don't really have a throttle, it indicates a serious malfunction that normally when this light comes on, the vehicle will be running in a reduced power mode just to get you to a shop to fix. Sometimes you can shut the key off and you can restart the vehicle and the light will be off, so that might get you to where you want to go. That's always worth a try when you have a warning light on, by the way, except for this one. This is the big one. That looks like a can of oil? When this read light is on, that means there is insufficient oil pressure in the engine, and that is critical. Now, that light can also go on because the sensor malfunctions, but you don't really want to make an assumption on that. I have owned vehicles where this light has come on, and if you don't hear a ticking noise in the engine, you could take a risk of driving it, but I wouldn't. If this light comes on, shut the engine off and have it towed to a shop and have it checked out. You'd be better to change the sensor than you would be to have to replace the engine if you make the wrong judgment call.
Mark: Would that be if you're a little bit not scared of lifting your hood, and what about checking your oil at that point?
Bernie: Absolutely. Yeah. That would be the first thing you'd want to do. Thank you, Mark, for mentioning that. Shut the engine off right away, and go check your oil level. Now, if the oil is low, add a litre at a time. I've had people who they look at the dipstick, oh my God, there's no oil in the engine, and they'll go get a five litre jug of oil, pour it all in at one time and then the engine is overfilled. Seen that many times. That's not a good thing to do.
Mark: That's really bad.
Bernie: Yeah. It is. Add a litre at a time. If it's way, way, way down, that's obviously it needs work. But this light is not a low oil level warning light, so just be aware that when this light comes on, it's usually a very serious issue unless the electrical sensor is bad, and that does happen from time to time. Sometimes it's not a bad thing, but you need to address it. Of all the lights on the vehicle, this is the one you want to take the most seriously because it's the one that can cost you the most amount of money to ignore.
Now, on the left side of the dash, we have this light that says plus, minus, it looks like a battery. It's basically, as Chrysler describes it, it's a low voltage warning light. It looks like it's a battery problem, but usually it'll indicate that the alternator's not functioning and charging the vehicle. But there's a number of other things that can happen. It can even indicate that the belt has jumped off the front because the alternator's belt driven. Now, you would notice that too because your power steering would become very stiff. If that light's on, and often some other lights will come on at the same time, it's a pretty good indication that your belt has skipped off. But not to diagnose stuff. When that light is on, it's something pretty serious to deal with. You may be able to drive the car, but not for long because modern vehicles consume a lot of electricity. Batteries, even good ones, don't last very long. You might be lucky if you got an hour's driving time before it dies. Diesels do require a lot of electricity to fire the fuel injectors as well, but gasoline motor, same kind of thing.
There we have our red lights. I'm just looking at a picture. See, on the Jeep as well, a couple lights that aren't on here. There's a low fuel amber low fuel warning light, so let's get into the amber lights. There's a low fuel warning light that'll come on here. Looks like a gasoline pump, so that'll come on when your fuel level is down to a certain point. Pretty self-explanatory. I'm just looking to see if there's anything else we're missing here. I think that's pretty much covers it. So, let's get into the amber lights.
This tire pressure monitor light. These lights will come on, sometimes they'll blink, sometimes they'll just be on, but any vehicle that has a tire pressure monitoring system, it's a fantastic feature because you don't really have to check your tires every week or every month. When the light comes on, that's when you need to pay attention to it. Again, unless you're noticing the vehicle's handling badly or making a thumping sound, because it could do that if it's lost all its pressure. If the light comes on, give a walk around the car and just look at your tires. Make sure none of them are flat. If they all look reasonable, go get the pressure checked as quickly as you can. Don't do any long highway trips. Make sure the pressures are all good first of all. If the light remains on, some vehicles require you to reset them. Jeeps are not like that. They have a sensor in the tire, so once the pressure's set, the light should go out. If it doesn't, then you have a problem with the system that needs to be addressed and you'll have to take it to a shop.
Over here, the ABS light. Now again, this is an amber light, but ABS is the antilock brake system. It basically provides better braking than the regular brake system, but without it, you'll still be able to stop the car fairly well. But again, that's a warning that there's a problem with the ABS system that needs to be addressed and you should take it to a shop and have it looked at.
Check engine light we discussed earlier. Again, if it's on, take it to a shop at some point, get it scanned and diagnosed. See what's going on with it. But if it's blinking, that's when you need to take a lot of caution. You should it repaired right away because you'll cause some costly damage.
Moving over to the right, we have the traction control system. Sometimes this light will come on. The traction control system helps the vehicle basically grip when it's slippery, so often it uses the ABS brake system to do this, or various other sensors. If there's a problem with the system, the light will be on all the time. But sometimes you might accelerate, say, on a slippery road and it'll loose traction and you'll actually feel it and this light will start blinking, and then it goes out. That's no big deal. That's just indicating something's happening. But if the light's on all the time, the traction control system's got an issue. A lot of times it'll come on with the ABS light because some of them work in conjunction with each other.
Finally, our last light is the ESP BAS. Now, ESP is electronic stability programming. BAS is a brake assisting system. That, again, these are electronic sensors often related with the traction control system, but it's basically there to keep your vehicle stable on the road. Some vehicles it'll tune your suspension system so it's essentially there so you don't lose control for simple things like going around a corner too fast. I'm not saying you should drive crazy around a corner, but it's when you lose traction for certain things, electronic sensors will come in and they'll activate the ABS brake system or activate the throttle and help you keep your car more stable on the road. These are all good things. Again, if this light's on, there's something going on that'll need to be checked, but again, they're amber lights.
A couple other lights I haven't talked about because they're not really warning lights are the turn signal lights. There's also the high/low beam indicator. The high/low beam indicator on a Jeep is here. It's usually a blue light. That's a long winded version of what's going on in your dash, and yeah. Again, with red lights, more serious. Amber lights, get it checked soon.
Mark: Thanks for going through that. Do you have any final thoughts?
Bernie: I think I just said it. Just red lights, take them seriously, especially that oil light. That's a really critical one, and also a number of vehicles have a, and we'll talk about these with different vehicles. I don't believe Jeep has a low oil level warning light, at least I haven't seen that when I looked through the manual, but this is a good reason to look through your owner's manual. If your vehicle has a low oil level warning light, this is a good light to have because when the oil gets down to a certain level, you can go check it and find, oh, it's low a litre or two and then you top it up and there you go. It's critical to know whether you have that versus the red oil can light because once that light comes on, it's serious stuff.
Mark: There you go. If you need more information about your vehicle or service, in fact, for your vehicle or repairs, the guys to see in Vancouver are Pawlik Automotive. You can reach them at (604) 327-7712. That's the number to call if you need to book an appointment in Vancouver, or check out our website, PawlikAutomotive.com. YouTube videos, Pawlik Auto Repair. Hundreds of videos on there about all makes and models of cars over the years, and of course thank you so much for listening to the podcast. Thanks Bernie.
Bernie: Thanks Mark. Just as a last thing, what should people do if they're not from the Vancouver area?
Mark: Feel free to search around and find a good service advisor, a good shop in your area to get your vehicle repaired. They will be able to give you the same kind of information and support that we do here on the internet. Thanks.
Bernie: Thank you. Thanks for watching.