TonyCD

My trusty steed is just shy of 150k now. Started 'er up cold, drove about 3 miles and suddenly got more lights than Christmas morning on the dash. "Check Transmission," then "Check Adaptive Headlights," then "Check Drive System," then they alternated among each other in that area beneath the speedo that usually shows innocuous white SH-AWD, mileage and tire pressure functions but turns into an amber screamer at times like this.

Properly terrified, I immediately dropped it off at my trusty mechanic. He concluded the code the car dropped was correct:
P0848 Open in 3rd Clutch Transmission Fluid Pressure Switch Circuit, or 3rd Clutch Transmission

It is impressive to me that they engineered this car to identify its problem part with such precision. I had no idea what a "3rd clutch transmission fluid pressure switch" was, but I since learned there are 2nd, 3rd and 4th switches in our RLs, and they're considered wear parts. Tellingly, my mechanic told me afterward that even though our cars were not hot sellers and are now over a dozen years old, the Acura dealer still had the switch in stock. What's more, the replacement switch is a different color than the original, implying to him they've improved the part.

I also have no idea why the idiot light went on not only for the transmission but also for the headlights and the SH-AWD, yet it did. A quick thread search here found a thread featuring two of our other owners, deepa1600 and rl015, who had pretty much this exact same thing happen to them: the failure of the 3rd clutch transmission fluid pressure switch triggered his dashboard to warn him of three different conditions, only one of which was his transmission. Reading their thread reminded me of something I'd seen but forgotten: the green "D" transmission indicator to the left of the speedometer blinking as the other warning lights blared. Thanks to rl015 for noting this: "Note to all: Dealer mentioned if there is a blinking "D" as part of these flashing lights, lamps, messages, etc. it is definitely pressure switch that is the culprit." Reading that gives more confidence amid the light show that we've actually found the problem.

https://acurazine.com/forums/second-...ission-961845/

My mechanic mentioned he's seen this problem on a few different Acuras (he services all makes, no special emphasis on this brand — long odds) in the last 12-18 months. He said "We only see this problem on Toyotas and Hondas. Reliable cars generally, but they can have this problem." Finally, I was amused by his grumbled take on why so many irrelevant lights came on: "I'm just cynical enough to think they made so many lights go on that you wouldn't even think of driving it another mile without getting it fixed."

stevieray

Had the exact same problem flare up, was the 3rd & 4th gear pressure switch, mine was happening when I"d shift too quickly from reverse to drive or vice versa. Replaced both switches, no more problems

TonyCD

Thanks. Good to hear confirmation. Seeing the multiple warnings makes me nervous there's some other electrical problem triggering the warnings — it's reassuring to hear this specific problem really happens.

HEAVY_RL

iTrader: (1)

It seems like all this hit me at once too.

The Christmas tree lights when shifting, this solved my problem:

https://www.ebay.com/itm/173904825426

The adaptive light error was fixed with this:

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1


FWIW I drove the car like this for a while and just reset the errors by turning the key off/on when I stopped.

TonyCD

Could you clarify on how you reset the errors (and whether that's a permanent reset method)?

And, thanks for the tip on the adaptive lights. We'll see whether that one was a fluke or whether it comes back on its own.

HEAVY_RL

iTrader: (1)

By reset, I meant I was driving around with the lights on. haha

thoiboi

lights are off when the car's off


and to OP, I'm sure there are a lot of parts you and I have never heard of under the hood

truonghthe

I already replaced my 3rd and 4th pressure switches lol, that the standard protocol that get carried over from the 3G TL.

TonyCD

Good to know. If this symptom recurs, I'll think 4th switch instantly.

I do have one question for anyone reading this: When this condition kicks on all the idiot lights, should I still consider the car drivable? It shifted pretty normally when the 3rd one went.

truonghthe

I wound't drive the car after knowing it finished and throw a code since they operate on pressure sensing. I had wrote an article about these pressure switch awhile back on the 3g TL section explain and provide actual data of these switches compare to new part.

TonyCD

Thanks. That answer and the related articles are very helpful info.

HDNBenjamin

I replaced 2nd, 3rd and 4th pressure switches. I'd say 3rd and 4th is pretty easy to get to if you want to try doing it yourself.

TonyCD

Sounds like the 3rd is the characteristic failure part. Is it worth it to replace the 2nd and 4th pre-emptively before they fail?

(And on a semi-related note, do most RL's justify pre-emptive replacement of the body position sensor, or does that one usually last the life of the car?