Check Engine Light / Coolant Levels and Reservoir

I was driving my 2014 Tundra Crewmax Limited home today, and I was startled to see the dreaded Check Engine light show up. Everything seemed fine with engine noise, performance, and observed temperature on the gauges. Thankfully, I was less than a mile from home, so I pulled up and shut down the truck.

I ordered a Check Engine Reader from Amazon, and it should be delivered tonight. That should allow me to diagnose the issue, but I also did the following:

• Ensured gas cap was on tight.
• Checked engine oil levels (90 minutes after shutting down engine); level looks good.
• Checked engine coolant, and notice the reservoir / overflow is completely empty. Also, there's residue along the reservoir exterior, under the overflow tube. I'm not sure how to interpret this.
• I opened up the radiator cap (again, 90 minutes after shutting down engine), and it doesn't appear like you can visually inspect the level from there.

This leads to the following questions:

1. How can I check the engine coolant levels, and why would I see spray residue under the overflow hose?
2. What type of coolant could I pick up at AutoZone or Walmart to fill / top off the Tundra coolant? Is there a preferred brand? Do you need Toyota's own coolant?
3. Is there anything I can do to diagnose / address an issue like this?

Thanks for any help you all can provide!

 

After searching the forum for some answers, I appreciate seeing some posts showing how to drain / fill the coolant radiator and reservoir. -- With the dealership closing, I'm just going to fill with Peak OET Asian Vehicles from AutoZone.

I'm still not sure what the best way is to check your coolant levels and why the side of the reservoir / overflow would have splash residue that looks like it was spraying out of the overflow tube.

Finally, is there a good way to diagnose the cause of running low on coolant? I assume I have a leak somewhere, but I haven't ever seen evidence of a leak in my work / home parking space.

 

This is what I would do first, however, with a full coolant system you can watch for bubbles in expansion tank without test kit.

https://youtu.be/4KDcRkiliuQ?si=rWQYYeFSFIEx555c

 

Actually, you should be able to see fluid in the radiator with the cap removed. On a cool motor, The coolant should be all the way up to the bottom of the inlet for the overflow tube. If you don’t see coolant up to this point, you’re low.

 

Thanks for the information on the engine coolant. I will look into a drain / fill, and I'll do my best to look for any additional evidence of a small leak.

I received my Check Engine Light (CEL) code reader, and it turns out I have a P0456 (EVAP Small Leak) code. -- Thus, though my manual inspection led me to focus on the coolant level (good thing I was led to check), the CEL problem appears to be an EVAP issue. I will order a $15 replacement gas cap, and I'll do some additional research on these threads, as I know the P0456 code is fairly common.

If anyone with P0456 experience is reading this thread, please share any helpful 1-2-3 steps for troubleshooting. (I assume replacing the gas gap is the cheapest and quickest possible fix. I'm not sure what steps 2 and 3 should be.)

Also, am I safe to continue driving the truck with this P0456 CEL code showing up?

 

Make sure cap is OEM. Ya safe to drive with P0465 just reset code and normaly it won't show back up for a while. a cheap smoke machine and some Youtube time will save time troubleshooting a P0465 if it comes back.