Car Doctor: How can I stop the alarm my car makes when driving with the rear hatch open?
Q: I have a 2021 Nissan Rogue. Sometimes I need to drive with the rear hatch open, such as when I have long lumber or other bulky items in the back. When the door is open — and while driving — an annoying tone is continually blaring.
I went through the setup pages on the steering wheel to shut off the tone but did not find any settings regarding the rear hatch door. I even tried to locate the source of the tone by removing the rear plastic bumper so I could install a switch inline with the device making the tone. I was unable to find the device.
Do you know a way to defeat this tone, or can you tell me its location so I can install a cut-off switch?
A: There was a time when courtesy lamps and tone alarms were controlled by pin switches in the door jamb.
Today, in many vehicles, the lights and warning are part of the door latch. It's not exactly the elegant solution of adding a switch, but you could try tripping the latch with a screwdriver by switching the latch to the locked position. I just tried it with a 2023 Hyundai Santa Fe that I am test-driving, and it kept the warning off.
A couple of weeks ago I was road evaluating a Honda CR-V and was using it to donate a couch to the Habitat store — the tone was dinging — and I just tripped the latch and all was quiet. You just need to push the unlock button for the hatch to reset the latch so the hatch will latch closed again.
When should coolant and transmission fluid be changed in Mazda CX-5?
Q: When should I change the coolant and transmission fluid on my 2018 Mazda CX-5? I tried getting info from my manual and found it difficult to understand.
A: The fluid levels and condition should be checked at every oil change. If the condition looks good, there is not much to do. The coolant is good for 120,000 miles, although there is not a specific time for coolant change. Ten to 12 years is about as long as you should go. If the transmission has no leaks — and the fluid looks good — then Mazda considers it a lifetime fill.
Can I use a scan tool to program aftermarket key fobs myself?
Q: I have a key fob that I want to program for my Dodge truck. I purchased the truck used with one fob that is pretty worn out. I found an aftermarket fob online for $50. The dealer wants to charge me $250 to program it and $500 if I buy the fob from them. They told me they do not normally program aftermarket fobs.
I have been looking online and found a scan tool from XTOOL (the model is D8) which, if I program two keys, would pay for the tool. Any thoughts on this tool?
A: All I know about this tool is what I have seen online, and it certainly appears to offer a lot of features for a relatively low price.
For consumer-level scan tools, I like the tools from Innova, as well as their Repair Solutions2 companion app, although — at this time — I do not believe they have a tool that can program key-fobs.
Shop owners tell me that they like the Launch and Autel bi-directional scan tools, in addition to their traditional scan tools from OTC or Snap-On.
I hope to be testing the Xtool scan tool in the near future.
Readers, have you used the Xtool scan tool? What do you think? Email me at jpaul@aaanortheast.com.
Trouble finding the source of an AC coolant leak
Q: We have a 2010 Lexus RX 350 — with 120,000 miles on it — that has been having air conditioning issues. My mechanic — whom we trust — has filled the system three or four times and checked for leaks over the last two seasons (blowing warm air). No leaks can be found.
He told us the only thing left to do is remove the dashboard and replace the unit, because that is the last place from which it could be leaking. He said he would replace the heater unit as well (he doesn’t want to do the job twice, since the car has 120,000 miles on it). He is also having a problem getting parts for this repair. Do you agree?
A: The technician more than likely added a dye to the system, and the evaporator is the only part they cannot see, so they are taking an educated guess.
Some shops use a "sniffer" that can test for leaking gas. It is a little tricky, since you need to charge the system and then — in a very still environment — use the gas probe to look for leaks.
I can understand replacing both the heater core and the air conditioner evaporator, since it is a 10-hour job. The only extra expense is the part.
The factory parts (which I assume your shop is telling you are hard to get) are $600 for the evaporator and $450 for the heater core. Aftermarket parts are much less expensive. Looking online at one company, 4-Seasons has the parts for about $100 each, through CarParts.com, CariD and Rock Auto.
John Paul is the AAA Northeast Car Doctor. He has more than 40 years of experience in the automobile industry and is an ASE-Certified Master Technician. Write to John Paul, The Car Doctor, at 110 Royal Little Drive, Providence, RI 02904. Or email jpaul@aaanortheast.com and put “Car Doctor” in the subject field. Follow him on Twitter @johnfpaul or on Facebook.
This article originally appeared on The Providence Journal: Car Doctor: Can I stop the alarm my car makes when the hatch is open?
