Acura604

covered under warranty... pressure switch fail at around 36000 miles.

The car finally popped a code ....it’s been doing the classic Honda transmission issue where it hesitates to get into gear and then lurches forward into gear violently. Covered under warranty - pressure switch failure.

The disappointing thing is the dealer had no clue over the course of 3 months....it’s such a common issue but they could only wait till the car popped the code. P0848.

Acura604

3rd pressure switch replaced... problem persists... same code popped... still at the dealership.....

thoiboi

Fluid been replaced?

Brown13

The last Guy that had this code found the fluid level low.

Acura604

Fluid was changed 2 weeks ago with a software update. it ran fine for about 4 days and then back to the transmission lurching issue....

got it back today...apparently they re-initialized the software after the replacement pressure switch was installed but the vehicle computer did not pick it up...they re-initialized it and ensured it was installed....

i'll find out next few days if the issue has been corrected.

nkelly

My RDX is doing the same thing between 20 mph and 25 mph when shifting from first to second...it slips and then kicks in really rough. I've recorded it on my iPhone a dozen times but the dealer says they can't reproduce it. This will be the 3rd time I drop it off. I'm really frustrated that this code, which describes it perfectly, hasn't popped up. The dealer says they can't do anything with this information until the code pops up and Acura approves. I'm also looking up the local lemon laws. This shouldn't happen with a car that cost this much fifteen months after you buy it. Sure, it's covered under warranty but what a hassle.

awoc

It's been going on for a while. Multiple complaints send to Acura and they do nothing about it. Dealerships have no clue most of the time on what to do about it. Without bulletins, they wont be active on finding a fix. Checkout this link. People with very low miles, to brand new RDXs complain of the issue. I had a 17 advance as a loaner, and it drove fine.
http://escapingthemidwest.com/new-acura-small-problem/

I looked at the pressure switches from the CL, to the Accords, and even TSXs have pressure switch problems. Why would they use such shitty pressure switches for decades?

I bought mine used with 60K and I thought it was from the dirty fluid. Changing it ,but it didn't help. I bought pressure switches, and i'm in the process of changing them out. The top two front green ones (front upper solenoid pack) didnt do the trick. More pressure switches to be purchased. This is turning into an expensive experiment.

The other thing I don't like is how much brake effort I have to apply at red light to keep the car stopped. Almost as if the clutch of the torque converter is engaged. It might be related to the incorrect pressure readings. Just want to see if anyone is having this issue as well.

dave08902

DTC P0848: Transmission Fluid Pressure Switch B (3rd Clutch) Circuit High
P0848 Transmission Fluid Pressure Switch B (3rd Clutch)

Circuit High
DTC (A/T)

1. Problem verification:
- 1. Press the engine start/stop button to select the ON mode.
- 2. Clear the DTC with the HDS.

Clear DTC

- 3. Raise the vehicle on a lift. Make sure it is securely supported, and allow all four wheels to rotate
freely.
- 4. Start the engine.
- 5. Disable the VSA by pressing the VSA OFF button.
NOTE: Enter the VSA maintenance mode in case of the
vehicle speed above 31 mph (50 km/h).
- 6. Run the vehicle in 3rd gear, and check the parameter(s) below with the HDS. Slow down, and
stop the wheels.

Signal
Threshold Current conditions
Values Unit Values Unit
3rd Pressure Switch ON

Do the current condition(s) match the threshold in 3rd gear?

YES

Intermittent failure, the system is OK at this time. Check for poor connections and loose terminals
between transmission fluid pressure switch B (3rd clutch) and the PCM. If the freeze data/on-board
snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the
freeze data/on-board snapshot.

NO

The failure is duplicated. Go to step 2.
2. Determine possible failure area (transmission fluid pressure switch B (3rd clutch), others):

- 1. Press the engine start/stop button to select the OFF mode.
- 2. Disconnect the following connector.
Transmission fluid pressure switch B (3rd clutch) 1P connector
- 3. Connect terminals A and B with a jumper wire.
Terminal A Transmission fluid pressure switch B (3rd clutch) 1P connector No. 1 (LT BLU)
Terminal B Body ground
- 4. Press the engine start/stop button to select the ON mode.
- 5. Check the parameter(s) below with the HDS.

Signal
Threshold Current conditions
Values Unit Values Unit
3rd Pressure Switch ON

Do the current condition(s) match the threshold?

YES

Replace transmission fluid pressure switch B (3rd clutch) .

NO

Go to step 3.

3. Open wire check (OP3SW line):

- 1. Press the engine start/stop button to select the OFF mode.
- 2. Remove the jumper wire.
- 3. Jump the SCS line with the HDS, and wait more than 1 minute.

SCS Short
- 4. Disconnect the following connector.
PCM connector B (51P)
- 5. Check for continuity between test points 1 and 2.

Test condition OFF mode
Transmission fluid pressure switch B (3rd clutch) 1P connector: disconnected

PCM connector B (51P): disconnected

Test circuit OP3SW

Test point 1 Transmission fluid pressure switch B (3rd clutch) 1P connector No. 1 (LT BLU)
Test point 2 PCM connector B (51P) No. 25 (LT BLU)

Is there continuity?

YES

The OP3SW wire is OK. Replace the PCM .

NO

Repair an open in the OP3SW wire between transmission fluid pressure switch B (3rd clutch) and the
PCM.

Djandy651

My car is CPO and they wouldn't cover the Transmission pressure switch. 385 repair. BS-Powertrain should cover it- don't believe anything the sales people will tell you at time of purchase. Looking back, I would only lease Acura's. Forget buying them- unreliable and Acura Client services won't do anything to help. You are just wasting your time. Acura knows it is a sinking ship- nothing they will do about it to right things. No appreciation for brand loyalty! Buyer beware- it isn't a luxury brand by no means.

Acura604

FYI.. update to my thread.. have not experienced any issues at all since the pressure switch replacement... "knocking on wood"...and i drive 100km every day.

awoc

Do you know what version software they uploaded? Maybe they wrote it on the receipt?

dave08902

Normally Acura uses a program called J2534 Re-Write. It scans the vehicle and it auto loads the latest software for vehicle based on Vin code. I used this program to load the latest software on my 2011 CRV, the dealer refused because they said it was not part of the TSB. After I loaded software, the CRV hesitation was finally fixed.

I don't think that they will write down the latest software version because the program auto selects the software to load,

awoc, if you want to know the version I have on my 18 RDX, I can look it up with my scanner.

awoc

My ebay HDS came with J2534 I just don't know if it's the latest update. I can't get it to log into any database for updates. I'm hoping it was closed with the latest file.

dave08902

The Rewrite software has all the firmware files included in it. The database version I have is dated April 2018. I checked My 18 RDX and it says all software is up to date.

DayManRDX

Hi - new to the forum first post yay!

Enjoying my new to me 2016 RDX and 3 days after buying it I'm having random transmission clunking/lurching issues. Intermittent but becoming more crazy - throwing codes and alerts. Looks like I'm in the right topic and forum. Thanks -

Here are my latest

egads

Seems like it's still under warranty and you have a check code set. As others here have said, there is a service bulletin for a software update. In some Hondas that TSB also includes a 3x fluid change.
As this RDX is new to you, do you have any service records? Those are usually a part of a Carfax. The RDX, like any Honda requires trans fluid changes every 30k. That's a 1/3 normal drain & fill. Never let anyone "flush" the fluid of a Honda/Acura.

DayManRDX

Took it in for service and it was covered under warranty. They replaced the 3rd pressure switch. Seemed to fix the problem for a week or so but first really cold morning the problem is back. Had to pull off highway (wouldn't shift into 5th) and turn off car to reset things. Started car and it shifted fine. When I have time I'll take it back to the dealer for another look.

DayManRDX

Returned to the dealer and turns out they had replaced the wrong pressure switch. This time they definitely replaced the 3rd gear pressure switch. Remember - it is ALWAYS the 3rd gear pressure switch. When you go in for clunking tranny tell them it is ALWAYS the 3rd gear pressure switch and to have the master tech clearly mark it for removal. Otherwise like me - You'll be back.

Tech

Dave, what did you check it with? What device? Did you use an OBD scanner or was it Acura specific?

The OBD scanners now are getting quite sophisticated and I am thinking about replacing my old Innova 3030 does nothing "reader" with one.
I already have the Durametric for the Porsche, a GS911 for the BMW motorcycle and had the Ross-Tech VCDS for the VW (which IMO was the best of the bunch).

dave08902

I used an Autel J2534 Pass-thru programmer and Honda Re-write software with a database date 9-2018. This device is not a scanner, it is a vehicle module programmer.

I can use this as a pass-thru device and use the Honda HDS software and it becomes an OEM scanner,

I also own the Autel 908P and the Launch Tech X431 scanners.

Mo_Green

Dave:

Where are you getting these writeups? Everytime you post I save it to my RDX folder.

Are these from the factory service manual?

I do all my own service/repairs; always had access to service manuals.

Many thanks and regards.

Tech

OK I am familiar with Autel, at least their cheaper scanners. I wasn't aware that they got into the upper end stuff. I've been looking at Foxwell and iCarSoft.

The Ross-Tech VCDS allowed coding which at the lowest price of all the slew of devices I had, made it a deal.

I am not familiar with the re-write software. Is this ECU mapping software and/or transmission software? Is this manufacturer supplied or from Autel / Launch Tech? I am a bit lost here.

dave08902

Autel and Launch have scanners that are 90-95 percent to OEM scanners, these are professional scanners and cost thousands. They also make a cheaper line for the DIY market.

The programming software is direct from the vehicle manufacturer. In this case Re-Write is from Honda and includes all the ECU files all modules in Honda and Acura.

When you code your module, it is done through the scanner and not the Re-Write software.

Coding is module configuration
Programming is replacing or updating the firmware to the module.