2006 Acura TL Overheating problem could kill your engine, quick fix
 

Executive Summary:

Inspect your Acura TL’s fan control relays using the images below as a guide. If they have white lettering on them that says OMRON you should replace them immediately. I ordered two of them from a Honda dealer on ebay for $17 ea. They are easy to replace. The images below are from my 2006 TL. For orientation, the bottom of the image is towards the front of the car.

Replacement part No. is 39794-SDA-A05

I bought two on ebay from a Honda dealer for $17 ea. Normal dealer price is $35. July 2016 prices.

Failure of these relays is common and it could lead to your engine overheating on very hot days if only one relay fails, or your engine overheating on any warm day if both of them fail. Your engine could be ruined as a result. This is a time bomb.

Details:

There are two electric fans behind the radiator that are turned on when the coolant temperature gets hot enough.

Each fan is controlled by it’s own relay, one called the fan relay and the other is called the condenser relay. They are both radiator fans but the condenser relay cools the AC condenser as well as the radiator, so they call it the condenser relay. Think of them both as radiator relays.

The relay that controls these important fans has developed a reliability problem and is the subject of at least one Technical Service Bulletin (tsb). Sadly there is no tsb regarding these relays as they relate to the radiator fans as far as I know. I think this is an oversight and am suspicious of Acura’s motivation for not issuing a tsb.

My 2006 TL has 205K miles and we are the original owners. We live in the Central Valley in California and are rarely stuck in traffic. 95% of our driving is at 65 mph. As a result we can drive a long time with only one fan working and never know it, since the fans are not needed at highway speeds.

A few years ago we were stopped for an accident and sat idling for 15 minutes in very warm weather. The engine started to overheat so I turned on the heater and when the car cooled off I turned off the engine. I replaced the thermostat and thought I had solved the problem. I was wrong.

Last week the same thing happened in 105 degree temps. I was stopped in traffic and the car started to get warm. When I inspected it I saw that the fan on the passenger side was not running.

I did some research on this site and found stories of the bad relay in other circuits. I got the part number from the local Acura dealer. The relays in question seem to be widely used in Acuras and Hondas. I assume that the relay had failed long ago and it was never an issue for me because we rarely sit in traffic, and that one fan working is enough unless the temperature of over 100 degrees.

When I received the new relays I pulled out the Omrons and replaced them. The car was warm, and when I started it up both fans started working. Success!

Spending $34 and replacing these two relays could save your engine. This post probably applies to lots of cars in the Honda/Acura family.

As an aside, I read the story of one unlucky Acura owner who had a problem with overheating and the dealer replaced several expensive components at significant cost to the owner. The problem re-surfaced two weeks later and the dealer figured out the problem was this fan relay. The nice dealer replaced the relay for free, since the owner had spent several hundred dollars replacing perfectly good components. Nice Dealer.

Carpe Relay!

Link to TSB??

tsb info link
 

Here is the link that pointed me to the tsb that discusses this relay:

https://acurazine.com/forums/1g-rdx-...pgrade-890420/

I was going to include it in the original article but then read it in detail and didn't agree with some of the author's statements, so I left it out. He cautions against replacing Omron relays with the newer 39794-SDA-A05 and opines about compatibility, yada yada yada.

In any event I confirmed with the local Acura dealer that the current replacement relay is 39794-SDA-A05

Awesome, My car is overheating in 100+ degrees only. Never on the freeway, unless in some pretty rare situations when the A/C is on and were sitting in traffic.

Sounds like it could be the relay.
 

That sounds like it. Take a look at your relays, as I describe, and replace if they are Omrons. Don't bother testing to see which one is bad, replace them both if they are Omrons, IMHO. Relays are $35 ea at the dealer or $17 ea on ebay.

Basically, it seems like one working fan is sufficient as long as the temperature is is below 100 degrees or you are always traveling at highway speeds. When you're traveling at 65 mph the fans are not needed as the ram air passing through the radiator keeps it cool.

The fans are only needed when you are stuck in traffic.

Your failure mode sounds like mine. My car only got hot when I sat in traffic and it was greater than 100 degrees.

My biggest concern is I have a gently driven high mileage car. The excessive engine temperatures could blow my head gasket and that would be very expensive. $34 for two relays seems like cheap insurance.

Yeah, I'm hoping that this is it because I'm not too fond of replacing the radiator just yet. I'll probably be getting the relays swapped out this weekend and see if it works. If it does I'll post back on this thread so I can help the next guy

When my car overheated the first time I bought a radiator. It is still sitting in the garage in a box.

I hope the relays solve your problem. It's a 5 minute job to change them. You need a pair of smallish pliers to grab the relays to pull them out. No tool needed to put them back in.

So....

My A/C Condenser fan was not working even when I turned on my A/C and let the car idle to reach the regular running temperature. I Replaced the relay and was bummed out because that didn't solve the problem but when looking at my radiator I did notice that my A/C Condenser fan was crooked and I literally had to force it with my hand (I had a brain fart and I feel stupid for not even checking for that first). Turns out that my Fan popped off the motor and my A/C Condenser fan motor was not working. I Called the AutoZone, O'Reilys, Pep Boys, etc. to get some quotes. Each place sold the Fan assembly and Motor separately & they run more then $180 all together. I always try to find cheap great working parts, so I searched around. I searched rockauto.com and they have the A/C Condenser fan for $55, $62 and some change after tax and shipping. I received it today and will be installing tomorrow morning. I will keep ya'll updated!!

Huh. Good heads up I'll keep an eye out as it gets damn hot up here in the midwest. I think both fans are working well, never seen a overheating problem but now will definiteyl keep this in the back of my head. Got a 06 TL here as well with only about 185k miles.

Pulled the fuse cover to check the relays and they are indeed made by omron. Checked on acuraoemparts and the part number and relay that comes up for me is the one ending with "3". 07 type s.

To E39: The part number ending in "3" which you describe is the original part number, for the Omron relay.

The new part number ends in "5", and I assume you would NOT get the omron relay if you bought that.

Omron was probably producing thousands of these relays every month when Honda/Acura discovered the reliability problem and stopped buying them. The "bad" (by which I mean the parts ending in "3 ") from Omron would logically flood the market.

The part number I put in the write up came from my local Acura Dealer, and is the new part number. I know there are plenty of Omron relays available on ebay. I asked for the fan relay if I remember correctly and that is what I was given as the part number.

FWIW I also checked with NAPA parts and they had a replacement for $25. No idea who made it because I bought the OEM relays on ebay.

To sum up, I bought two "39794-SDA-A05" relays from an Acura dealer on Ebay for $17 ea. I replaced both relays in my 2006 Acura TL base model. My fans starting working. I smiled.

YMMV. :-)

Good Luck with whatever you decide.

Just curious, is this the same part number for '05? I'm on Amazon and it says it wouldn't fit my TL

@ jimmyfu: Third generation Acura TL is 2004-2008.

If I had a question like you just asked, I would probably call my local Acura Dealer parts department and ask how much the fan relay was, and did they have any in stock? Can you give me the part number?

But just to keep it simple. This is a simple Single pole Double throw relay that is commonly used in Hondas and Acuras. Now, it is nuclear powered and liquid nitrogen cooled and has superconducting magnets and stuff, but otherwise it is pretty common.

Some of this post may not be true.

Check Amazon for the best information...
_____________________________________________

Seriously, Jimmyfu...

The current part number for the 2 relays for my 06 TL is this>>>>> 39794-SDA-A05

The previous part number, which is an Omron relay that is a POS and causes failures, is this>>>>>39794-SDA-A03

The part number that ends in 5 is the new number and is not the Omron relay that might kill your engine.

The old part number ends in 3 and is the Omron relay that might kill your engine, and I'm almost SURE you can find lots of those on Amazon and Ebay.

And if you are unable or unwilling to read and understand this discussion...well, maybe an Acura TL with a dead engine is the best outcome for Society. I'm not sure.

I've had a couple glasses of wine so please read this in the next few hours because I will probably get up in the middle of the night and replace this snarky comment with sensitive poetry about dandelions and stuff.

Old part number, new part number
 

The new part number for these relays is 39794-SDA-A05 <<< Good Relay!!!!

The old part number for these relays is 39794-SDA-A03 <<<< Bad, Bad, Bad Relay!!!!

The only difference is the last digit. 3 is bad. 5 is good.

A little story:

I was getting an MBA from USC (Go Trojans!) in the mid-90s and I worked at a Toyota plant that made the Tacoma Truck beds. I learned a lot about the Toyota Production System, TPS.

If a part ever failed in the warranty period, that part would be put on a table for the workers to look at when the came to work. It was called the table of shame.
I think the idea was the workers would naturally look for any failures of that part that mess up production, and report them to management or their lead or whomever. ( I am guessing here, because the Tacoma truck beds were made out of raw steel and had almost no outside parts that I can think of.)

I am almost certain that Honda/Acura has the same system. When the relays started failing, I'm sure that Honda got a Tiger Team on the relays immediately and analyzed the stuffing out of the problem and discovered that the relays were junk and got them OUT of the product ASAP. You have to realize that a failure of a $2 (Honda Cost) relay like this can lead to the failure of an engine (worst cast) which can cost the company thousands of dollars to replace, and they have to smile while they are doing it.

So, DO NOT buy the old relays because you got a great deal on a genuine Acura part on Amazon or Ebay for the bad relay that ends in 3. Buy the current relay that ends in 5, from Honda/Acura for $17. Why buy the new relay for $17 instead of the old part number for $5? Good question. Because the Honda/Acura Tiger Team, after getting burned by the Omron Relay, probably analyzed the stuffing out of the new relay. The new relay is good enough to go on the Apollo mission. I mentioned the Apollo mission, so now you know I am old.

And wise.

Thanks for the clarification - I'll excuse the snarkiness due to the admission of wine. I actually checked oemacuraparts and the part number with the 5 shows that only "also fits" the ILX, MDX, and RDX. Secondly, wasn't sure if the minor jump from '05 -> '06 would be any different. I.e. '07-'08 TLs use WHITE navi discs, while the rest use Orange.

Thanks for excusing the snarkiness. Very nice of you.

I can totally see the nav discs changing over the 4 years with...you know, computer stuff.

Anyway, quick answer is this: The relay ending in "5" is the direct replacement for the relay ending in "3" This is a SPDT relay and there are probably 15 of them in the car, scattered around...

But these are the ones that can kill your engine

My car came with a "3" and the Acura replacement is now a "5".

If you replace the relays you will look at them both and say "Well, Duh!"

Thanks again....

After replacing my A/C Condenser fan it still does not work :(. I replaced both fan relays with a different brand and still only the radiator fan is working. Anyone have any idea's of what else it could be? It's a pain in the ass to drive around with no A/C. Is there any other fuses or relays that can possibly cause issues with the fans? I honestly do not want to take it to a dealer and have them charge me 400 bucks for a job I can do in like 10 minutes for 10 bucks

interesting thread. i just checked my fuse box on my 08 type s and i have the omron ones. i'll probably buy the two news ones with the 5 at the end and put them in. small pliers should work like you said right? also do we need to put dielectric grease on the connection pins?

i don't live somewhere that gets super crazy hot but i figure i'll just replace them now since i'm 8 years into ownership and plan to have it a little while longer.

just for confirmation, we don't need to replace any other relays with this same part number? when i looked them up online there were like 12 other ones with the same part number in the cabin.

This is for Williamv and sockr1:

I suggest you take a look at this write up:

https://acurazine.com/forums/1g-rdx-...pgrade-890420/

Goes into a more detailed discussion of the bad and good relay and where they are used.

Williamv...the relay is used in other places in the AC system ( and throughout the car). While his discussion centers on another model, I'm pretty sure that Acura has not re-designed the AC system for the TL vs. the MDX.

i did but please read my first paragraph and provide your input...i know what the other guy said. i wanted your thoughts.

my last paragraph was also asking for confirmation (aka what you did...it sounds like you only did those two but wanted to make sure)

Did you mention they can be in any Acura?

Here's an RL's.. I'm guessing its the black ones? Only the green ones are by that brand names. Nothing to change?

https://cimg7.ibsrv.net/gimg/acurazi...9d1c86c4bf.jpg

Sub'd :thumbsup:

Thanks for the reply Sockr1.

I used a small set of pliers to pull them out because I could not get a grip on them. Regarding contact grease, I didn't use any. I did not notice any residue that looked like it was used before, but honestly I could be wrong. I'm a pilot, an electrical engineer with an MBA, an abstract artist, a concrete analyst, and a ruthless bookie. However, I am not a certified Acura Service Technician.

You are correct that I only replaced the two relays that control the fans. Let me share that I just had my AC system recharged about 3 months ago and everything was fine, but the car sat for two weeks and then the AC cooling was Kaput. Upon re-reading the post I shared with you I see that a failed relay can cause spiking in the AC refrigerant pressure and a loss of refrigerant. My Acura is at the shop and we will see if it was a leak or it blew our the refrigerant because of a spike. I have this great service guy (Charlie's Automotive in Clovis, CA) and I mentioned the relay problems and he knew about the failed relay draining the battery. Charlie rocks. Anyway, what I'm getting at is I may be finding out that more of the relays need to be replaced and I will regret not replacing them all, which I will do shortly.

Best Regards,

Thank you so much for your detailed response! I'll get to moving on replacing those two relays just for peace of mind. Keep us updated on your service you're getting done and thanks for making the community aware of this possible issue!

Update on AC system
 

The problem with my AC system was the small schrader valves (like Tire valves) on the recharge ports. They were leaking coolant. The shop replaced them and rechaged the system for no charge.

I paid $130 to have the system evacuated and recharged and that came with a 6 month guarantee that I would not have to pay for any more freon. Instead of charging me for troubleshooting and replacing the two 50 cent valves, Charlie's automotive in Clovis, CA did it for free. Charlie knows that he has a loyal customer as a result. Charlie is smart. Be like Charlie.

To: RL09

Your picture of the fuse/relay box lookes pretty much identical to my 2006 Acura TL. I would guess the two black relays control the fans. Your picture shows that they are Denso relays, not Omron.

Someone more knowledgeable on the cooling fans might disagree. To test the relays I would get the car warmed up on a hot day and have it sitting with the AC in Auto mode and engine running. Pop the hood, both fans should be running.

I had this same issue on my 2004.
Thanks for sharing all of this...great thread.

and you're funny, to boot.

Much appreciated. Gonna test that.

Sometimes my arm is hanging out the window at a traffic light, and the crazy heat coming on it from the engine is just too much. the first car i feel that. Yet, the temperature is a bit below half-way thru. :dunno:

How to see if your relays and/or fans are working
 

Earlier in this thread I talked about testing the operation of your fans and I said the car needed to be warmed up. I may have been wrong.

On my 2006 TL I started the car on a warm (85 degrees F) day and with the AC on (Auto mode) both fans were running. The car was cold.

So, to check the operation of your relays all you need to do is start your car (with the AC on, which is Auto mode) and open the hood and see if they fans are running.

Got my AC fan working !
 

I got both my fans working at the same time. Turns out the fan was broken off so I purchased a new one from rockauto.com and I switched both relays for my condenser fan and my radiator fan and still no luck. The only two options I could Think of is that the AC fan was not receiving electrical current or a fuse in the hoods fuse box was out. I checked the fuse for the AC fan and poof!!! The 30a fuse was blown. I replaced it and NO MORE OVER HEATING! Now I can drive with my AC in 100 degree weather with no worries!! Hope this helps anyone/everyone

Congrats on your diagnosis and fix - :cheers:

Great to hear you got it sorted out...
 

Good to hear your problem is fixed. I'll keep an eye on my fans if the Temp of the engine starts to climb. Thanks for sharing your experiences.

ok so i recently posted a thread on my 06 TL, I HAVE not only bought new fans (condenser, and AC) thinking that it was a fan issue because i replaced all of the fuses AND relays within the last 3 months. i literally am at the end of the rope. BOTH fans are receiving power because i used a test light to find out. also i tested both fans to see if they had good motors in them. both worked fine.

i don't know what else to do, maybe i will change out the relays one last time. maybe i got faulty relays when i bought them 4 months ago.

FYI : SOMETHING INTERESTING I WANTED TO MENTION IS THAT I DID HEAR CLICKING UNDER THE FUSE BOX COMING DIRECTLY FROM THE RELAY THAT CONTROLS THE FANS. IT SOUNDS LIKE IT WAS CLICKING ON AND OFF. NOW, ITS NOT CLICKING AT ALL. SO IM GUESSING THE RELAY WAS GIONG BAD AND NOW IT HAS COMPLETELY GIVEN UP. I WILL POST AS SOON AS I REPLACE THEM TOMORROW MORNING BECAUSE LIKE I SAID I HAVE DONE LITERALLY EVERYTHING INCLUDING RECHARGING THE AC.

THANKS FOR THE WRITE UP!

The Good Earth...
 

[QUOTE=njresendez;15844344]ok so i recently posted a thread on my 06 TL, I HAVE not only bought new fans (condenser, and AC) thinking that it was a fan issue because i replaced all of the fuses AND relays within the last 3 months. i literally am at the end of the rope. BOTH fans are receiving power because i used a test light to find out. also i tested both fans to see if they had good motors in them. both worked fine.

i don't know what else to do, maybe i will change out the relays one last time. maybe i got faulty relays when i bought them 4 months ago.

FYI : SOMETHING INTERESTING I WANTED TO MENTION IS THAT I DID HEAR CLICKING UNDER THE FUSE BOX COMING DIRECTLY FROM THE RELAY THAT CONTROLS THE FANS. IT SOUNDS LIKE IT WAS CLICKING ON AND OFF. NOW, ITS NOT CLICKING AT ALL. SO IM GUESSING THE RELAY WAS GIONG BAD AND NOW IT HAS COMPLETELY GIVEN UP. I WILL POST AS SOON AS I REPLACE THEM TOMORROW MORNING BECAUSE LIKE I SAID I HAVE DONE LITERALLY EVERYTHING INCLUDING RECHARGING THE AC.

================================

You have obviously put lots of thought and effort into this. I don't see anything obvious so I will post some snips from the manual in the hopes they come in handy. They are likely more helpful than my musings.

I have one observation I will share: you seem to be addressing all the logical failure possibilities. Some of the things you are describing seem nonsensical, and whenever I encounter that on a vehicle electrical problem I remember the words of a wise old mechanic: "Have you checked the ground?"

The electrical system switches and works on 12 volts DC, and grounds everything back to the frame and/or engine. If I were you I would take the time to trace the wire harness and find the grounding point for that section of the harness and confirm it is tight and corrosion free. When you have a bad or intermittent ground then the circuits find their ground through other paths and pandemonium ensues. It is possible that a ground strap from the engine grounding the engine to the frame has been broken or removed (I'm totally guessing here, btw) and that could lead to weird stuff. I'm just a shade tree mechanic, but my degree is in Electrical Engineering...so I got that going for me. (I want extra points for the Caddy Shack reference.)

https://cimg6.ibsrv.net/gimg/acurazi...23414dd660.jpgThis shows you where to connect 12 volts and ground to test the fans

https://cimg2.ibsrv.net/gimg/acurazi...33a0cf5138.jpgAcura seems to have thought this out...

https://cimg3.ibsrv.net/gimg/acurazi...b1415aa357.jpgMore wisdom...

https://cimg4.ibsrv.net/gimg/acurazi...dbf7616c5f.jpgThis should help some.

ok so i finally figured out the issue after 3 days of searching and buying fans, relays, etc.

So just as you said RJS AVIATION , i checked the ground and this is what happened.....

so i purchsed an intake the V2 AEM . with the dual chamber there is a small bracket at the bottom of the intake. so i saw where they matched up with a bolt that just so happened to GROUND several wires in the driver side wheel well.

i guess the metal bracket from the intake was blocking the ground connection to the car from the wires that were there originally. so i unhinged the bracket and tightened down the ground connections one more time and turned the car on and WHALLA!! I HAVE A/C. and the car is not overheating. both fans are functioning properly.

THANK YOU for the info all the help is appreciated seriously!

...Yeah, that wise old mechanic was pretty smart.

Glad you found your problem.


...No comment about the Caddy Shack reference, or the title of my reply? I put a lot of thought into this, pal...how about a little somethin', you know, for the effort? (yet another Caddy Shack reference. I'm hot today, man!)

glad you found your issue and it's solved! for the aem v2 install you're supposed to relocate that ground to another hole...did you not do that and try to put the ground/rubber intake mount all in the same spot?

Just purchased our 06 , and noticed how hot the engine bay runs , Ordered the part number through ebay , once install the relays i will also removed all the plastic panels. The fans are running great , any other suggestions ? the TL has 78k

It is not clear to me if you have changed the relays (or not) and if you have, if that reduced the engine temperature. Feel free to clarify for me.

Regarding removing the plastic panels....I wouldn't do that, but that is just me. Most of them are for cosmetic reasons, I assume, but I'm not going to second guess the Acura engineers. We have 206K miles on our 06 TL and the plastic covers are in place.

I replaced the stock rims with smaller 16 inch rims from another Acura, with taller tires. The car is much quieter as a result.

I apologize for the misunderstanding , my cell typing skills suck!

Fist i would like to thank you all for this post , as i was worried about my engine bay being way to hot, so i went ahead an ordered the relays you guys provided 8)( . it should be here Saturday. i shall install it then . I got the idea of removing all the excessive plastic in the engine bay from reading the post " ultimate cooling mod" https://acurazine.com/forums/3g-tl-p...ng-mod-739098/
was just curious if that would help as well.

everything else as far as the fans seem fine I will check to see if there is a coolant leak, water pump , and possible faulty thermostat.

thank you so much for the reply . But as far as your knowledge , the relays should do the trick ?