rkthunder13

Hello again, after some pointers from forum members my idle is much better on my new (to me) Civic!

I have done a relearn procedure by removing the battery cables after a tune up. After a cruise the only code I get is P0705 trans range sensor circuit malfunction which ive cleared and it's returned several times so I'm ready to address it.
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I am having problems tracking down exactly what and where this thing is. I think it's just the neutral safety switch in the gear selector console but I'm not 100% confident.

Has anyone had trouble with this before? Any help is appreciated!

rkthunder13

rkthunder13

I also feel it's worth mentioning that my gear selector light on the dash works perfectly.

muellersfan

P0705 is not a Honda code. If you clear the code, does it return? If so, jump the service connector and watch the D4 light in the cluster blink out the code. Post it.

rkthunder13

Next step is to jump that terminal do you have a pinout of those plug?

I went to 2 auto parts store to compare their codes with mine on the Bosch scanner.

Both stores got p0700(a general code) and p0740 TC clutch system failure!

Time for the trans to come out? Need a new torque converter? My mil light also doesn't glow at all even with engine off key on. Could I have an ecu or TCM issue? This sucks it's my new DD and this could shut all that down.

Thanks for your response by the way!
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rkthunder13

tony_2018

If your tc is toast I'm going to assume your tranny is too.

rkthunder13

I was afraid of that. I'll do a drain and fill a few times with dw1 a few times to see if it's varnish in the valve body...the fluid doesn't look too good... Shift from 2-3 is kind of "prolonged" the other gears are smooth and firm.

I did pull and test the ab solenoids on the front of the transmission. The audible click from one was not as strong as the other. Ohms tested ok

Any good sources for cheap transmissions for this car, is rebuilding it something that can be done in the garage? I've only done th400 and 4l80e

muellersfan

How long have you owned the Civic? Has the transmission been swapped by you or a previous owner?

Any shifting problems?

rkthunder13

It's my second week owning it 120,000 miles on the car and I'm the 3rd owner.

The transmission Vin matches the Vin in the car so it's the born with trans I think. I'm not sure if it's relivant but the engine was a y8 and at some point someone replaced the block with a y7. The head and intake are the original y8 equipment.

All shifts are good except 2-3 it feels like it takes a split second longer to engage 3rd but I wouldn't call it bad shifting by any means.

How long are the odds that the poor old transmission just needs some fresh fluid on those clutches?

muellersfan

Is a Y7 or Y8 ECU installed?

rkthunder13

Ecu is 37820-P2P-A84, from what I've found it's a Y8 unit.

muellersfan

Try multiple ATF drain-refill cycles. Castrol Import Multi-Vehicle ATF has yielded good results for me. Shop around for the lowest price on the 1 gallon jug.

rkthunder13

Is that atf pretty commonly used in Honda transmissions? I've been wanting to drain and refill but the Honda dealership is closed until Monday.

If I can just go get some Castrol import atf in the morning I'll get it done and see what it'll do.

Is the Castrol up to Honda specs?

muellersfan

Yes. It's designed for Japanese auto transmissions, and is less expensive than Honda ATF. My Civic auto transmission has been shifting very smoothly for >10 years using Castrol Import ATF.

Be sure to SLOWLY shift through every gear multiple times between each drain-refill cycle.

rkthunder13

I'll pick up a gallon tomorrow and start the first of several drain and fills.

Thanks for that tip!!

muellersfan

Be sure to SLOWLY shift through every gear multiple times with engine idling between each drain-refill cycle.

rkthunder13

Okay I'll be sure to do that for sure. How much should I expect to come out?

I've heard from 2.5-3 quarts, I've also read these cars should be checked on level ground and not running? Most cars I've had are checked hot and in park running

muellersfan

2.9 quarts.

Note that less than half of the total ATF is removed after a drain. That's why minimally three drain-refill cycles should be done. I would recommend five.

Correct, but after engine is fully warmed up.

rkthunder13

I picked up 2 gallons to start with and 5 drain and refills is what I will do!

Thanks for all of the information, also manual are you using? I'd like to find one of those also.

Thanks again I'll follow the procedure and keep the forum posted.

rkthunder13

rkthunder13

Well that transmission sure did want that!!

The magnet was horrible. No aluminum shavings to speak of except 1 or 2 flakes...no pencil shavings like I've seen on TC failures in the past. As you can see that fluid was dark dark but not burnt. 5 quarts came out of there so it was overfilled.

So far it's shifting smoother after the 1st 3 quarts. I'll be doing a 3qt drain and fill each day for the next 5 days. After the 5th drain and fill I'll reset the ecu to see if it's still throws p0740!

Thanks to everyone for their advice and guidance!! I'll report back after the results.

Also does anyone have a diagram for the solenoids for this trans. I seen an assembly near the drain plug that looks just like the top 2 a/b solenionds. What do these solenoids do and could one of those lower ones casue p0740?

rkthunder13

I'm on my 5th flush with dw-1 and the shift quality has vastly improved. And so far no codes after the first 100 miles. I'm hoping for the best. Thanks to everyone for the advice!

muellersfan