19Accord97

To make a long story short, I converted my 97 Accord LX from an automatic to a manual. About 300 miles later, constantly fixing small issues that popped up, and then finally not being able to move the shifter into any gear, I swapped the A/T tranny back in. I've had the car for 11 years and the automatic transmission has never had any issues whatsoever and every 15,000-30,000 miles I would do a drain and refill 3x times ONLY using Honda ATF.

Ive got the car back together and now I am getting a P0715 CEL. I cleared the code and after driving about 20 seconds the light came back. But, before driving the car with the A/T back in it for the first time, I removed the drain plug, ran 1 qt of Castrol import ATF fluid, closed the drain plug, filled with 2 qts of Castrol Import ATF fluid, and then drained it again (I never drove/started the car with the castrol fluid). Then, I put the drain plug back in and filled to the proper level with Honda ATF fluid.

I am assuming the transmission is fine since I have never had any problems with it before the swap and I took great care of it. I see one solenoid through the passenger side wheel well, but not the second that I have heard to look at. I feel like an idiot, but how do I remove the solenoids to clean them without breaking them? I just want to make sure I dont break one and then be stuck with the car sitting for another few months.

Thank You!



Less importantly, I bought a used auto shift console to throw in there instead of soldering all the wires back together. However, when I press the brake pedal, it will not unlock the shifter and I don't hear the click that I used to. Instead, I have to use a key and use the manual override to get out of Park. The brake lights work fine. A guy send me two parts to replace, but I figured I would ask here first before taking the console all back out and replacing the two parts.

StokelesS_g2

O man, I was eating, but just had to run outside and look really fast.

Just 3 10mm bolts and unplug the wire harness.
Youtube DIY link

19Accord97

Thanks! I dont think that is the correct solenoid/sensor. I read on another thread that is was viewable from the passenger side wheel well and there are 2 sensors that should be checked, cleaned, and replaced.

MAD_MIKE

P0715 is just OBDII for TCU code 15, which is for the NM sensor on the right side cover. Pull both the NM and NC sensors and make sure they are clean. Next would be to check that the wire harness is damage free and all the connectors are properly together with clean/tight connections.

If the Interlock is not unlocking, verify the solenoid is getting power first. If not then check up at the pedal switch.

19Accord97

On my cheap scanner, it says "Turbine/Input shaft speed sensor circuit - confirmed"

What are the NM and NC sensors?

When looking at the cover of the tranny, I only see one sensor which is located towards the rear. How do I pull those sensors out of the transmission? I had a heck of a time getting that wire plugged back in when I reinstalled it and my hands are large so I have a heck of a time getting in that tiny spot. If i can figure out how to get the sensors out and cleaned, I will go ahead and do that, clear the code, test drive, and report back.

Thanks for the help so far!

Sorry for the "noob" question, I just don't want to break the sensor and then have it sit for another year.

MAD_MIKE

Turbine/input shaft is the same as the NM(Mainshaft) sensor. Never go by most OBDII reader descriptions as they are usually very generic. Always go by code and look up the manufactures description.

NC is the the Counter shaft sensor. See what Honda did there.



You will need to be careful. Remove the 10mm headed bolt and then gently prise/twist the sensor locking tab to break it free. From there is a gently twisting while pulling up. It can be a right mother.

19Accord97

Thank You for clearing that up, i appreciate it!
So it should be referring to the NM speed sesor?
That looks to be easier to get to while under the car.
Is the little black circle a washer or is that a gasket that will need to be replaced before i put it back in?

Thanks for the help! I'm hoping this will fix the CEL and then i can focus on the brake safety switch.

MAD_MIKE

Yup. But if the NM is gummed up the NC is probably nearly as bad, best to pull both and verify they don't have any junk on em.
NM is easy to get to with the wheel turned. NC is easy to get as well, work it blind mostly. Pretty sure the radius rod would be in your way to try to remove the NC from under the car.
It is an O-ring seal.
I do, but I have also pulled them out, wiped them down and reinstalled with a little ATF. There is no pressurized fluid there, it is mostly a dust seal. IIRC they were a few cents from Honda.

19Accord97

Thanks again!

I tried getting to the NM sensor but my shorty 1/4" socket and my 10mm wrench wouldnt work due to lack of space. Im guessing I'll have to loosen the tranny mount to drop it a bit. Hopefully that's all i need to do to get enough room.

MAD_MIKE

Use the box end of a wrench. If that doesn't work try a 10mm brake bleeder wrench.

19Accord97

I ended up cutting my harbor freight socket in half and it gave me just enough room to get the bolt removed!

Alright Mad_Mike, I went ahead and cleaned both sensors. Neither were covered with much material at all and I could clearly see the brass tip of each sensor. I wiped them off, reinstalled, cleared the code, CEL went off, and then when I started the car and put it in gear, the CEL came right back on with the same code.

Where do I go from here?

MAD_MIKE

Check that the sensor is 400-600Ω 68°F/20°C.
Check that the wire harness is not damaged and the connections are clean and tight between the sensor and PCM.

Not sure on the 96/97s but on the 94/95s it is an Orange/Blue wire on D19 for the TCU and White/Blue wire on D12 for the TCU, verify the resistance is the same at the two at the PCM connector. I haven't looked at the '97 in ages so I cannot recall if there is a TCU/ECU or PCM.

Since this is a re-work/re-installation of the AT, verify the wiring harness has not been crushed/tugged/damaged in any way.

19Accord97

The TCU for the 96/97 is within the ECU whereas the 94/95 TCU is a separate module next to the ECU.

I did have a heck of a time getting the NM sensor wiring plug plugged in when reinstalling the transmission; it seemed as though the wiring was too short. I'll go ahead and pickup some electrical cleaner, and clean both parts of that connection.
I am a novice 100% when it comes to multimeter use. I haven't even used mine before (I got it for free from Harbor Freight 7 Function Multimeter ). Which Ω setting do I put it on and which hole do I put the red and black plugs in?

Now that you have mentioned the plug/wiring harness in addition to the transmission working great before I pulled it out, I am thinking either I pulled to hard on the NM wiring plug or that connection isn't 100% clipped in.

Thanks again! I'm ready to get this thing on the road.

MAD_MIKE

Wiring should not be too short.
Verify the wire harness is not going under/over something it shouldn't.

Turn the dial to '1K' to measure.

19Accord97

Just tested the sensor and i got 487 ohms.

Is there a way i can test the female plug from the wiring harness that goes to the male plug on the sensor? If so, what settings in the multimeter should i select?
Thanks again!

MAD_MIKE

Plug it into the sensor and use some pins to back probe that connector and check for the sensors resistance. Trace the wires to the PCM and back probe to verify that there is still continuity in the harness for the sensor.
If you have continuity/correct resistance for the sensor all the way back to the PCM, check that the connector at the PCM has not been damaged or the pins have been loosened/damaged in the connector.

19Accord97

By PCM, you mean ECU?

When doing the swap, i had to swap out the ECU for a manual so maybe you're right and one of the plugs is loose. Any idea which plug or wires i would test at the ECU?

After work I'll clear the code, unplug the ECU, plug everything firmly back into the ECU and test again. I think i might have an extra auto ECU so i will try that one as well.

Can you walk me through backprobing? Sorry for the "baby stepping", i just have never had to find, trace, or diagnose any electrical issues. I just figured i could put the multimeter on the femal plug from the harness and see if there was any signal or power to verify there isn't a broken wire or something.

MAD_MIKE

If the ECU and TCU are separate they are called 'ECU' and 'TCU', if it is just a single ECM it is called a 'Powertrain control module' or PCM.
You will need to use the AT ECU or AT PCM with the AT. Data is shared between ECU/TCU. An MT computer will not have provisions for AT, and will not work correctly with an AT.

Use some pins or anything metallic and long enough to stick into the back of the connector while its connected. That way you can test everything in situ.

19Accord97

Thank you for the clarification. I have the original auto PCM installed now but i will swap in the extra auto pcm to see if that makes a difference.

I have not had time to work on it any more but will add soon as i can. Ill update with results ASAP on both the PCM swap and the backprobing.

Thanks Mike

19Accord97

Finally got it figured out!
The wires were pulled out of the plug a bit, so I cleaned all the connections and got it put back together.

Thank You for all of your help, couldn't have done it without you!

Next is the brake safety switch