I have a 98 CR-V auto, and it started doing something wierd today. I was crawling in traffic, so I'd been in 1st gear for a while, and suddenly the transmission would seem to go into neutral. I tried shifting into 1st and 2nd manually, and it made no difference. When I stopped and restarted the engine, however, to tranny returned to normal right away.

This happened a couple more times in traffic, then on the freeway in 4th, that at a stoplight. It's very disconcerting, and very sudden. I've never had problems before today.

I don't think it's anything mechanically wrong with the transmission because restarting the engine makes it go away.

Has anyone seen a problem like this or know how to fix it?

Update:

My engine check light came on after my post, and the DTCs it gave me were these:

P0740 - Faulty (Torque Converter) lock-up control system,
P0730 - Faulty shift control system.

Those are literally the symptoms of to problem I'm having, but it's nice to see my car agree with me.

I'm still a little stumped as to why the problem will go away just by stopping at restarting the engine. It works even if the car is hot, or if I'm still moving because I didn't want to pull over.

I'm pretty sure there's not on actual mechanical problem with my transmission because after restarting the engine, the transmission behaves completely normal, like nothing happened, even if it's hot, even if I'm still moving, even if I only stop the engine for a couple of seconds.

I'm going to change my transmission oil tomorrow. I'll post an update after that.

Second Update:

I I changed my transmission fluid, and the problem got worse. Not worse per say, but it would happen after a shorter period of time consistently. I then put the old fluid back into the transmission, and the same thing happened. I could drive for even shorter periods of time before your transmission would shift out.

I then checked all the transmission solenoids, and they will have the correct resistance, and they all function. I also cleared the computer memory, and test drove it again. And the problem seemed to get better, or rather it would take longer again for the problem to occur. Not as long as before I change the fluid the first time, but longer than before I cleared the computer memory.

 

As I was hinting at earlier, I had wanted to replace my PCM, so I did that, but it made no difference, so with that ruled out, I found some interesting advice from several places that pointed to the oil filter being clogged. Seems like junk would block the filter, the transmission would lose oil pressure, and the gears would disengage. When the engine stops, the transmission oil pump would stop with it. The junk would then fall out of the filter, and the transmission would work normally until he junk blocked the oil filter again.

Turns out that's exactly what it was.

The problem is that you have to remove and disassemble the transmission to replace the Tranny's oil filter. Given that I don't have a spare 2k to spend on a transmission rebuild, I didn't want to do that.

Turns out CR-V transmissions have oil pressure inspection ports. You pull a plug out, and install an oil pressure gauge, then you operate the engine and transmission and check the oil pressure. There is one port for each of the 5 clutches, and one for the main pressure line. Checking the hydraulic control chart in my service manual, I found the Line port is right after the oil pump, which is right after the filter, and the Line port is right on the top of the transmission, by the lock-up control solenoids.

I figured I could reverse-flush the oil filter by blowing compressed air into the Line port, and I was right!

My procedure is this:
Put drain pan under vehicle.
Charge air compressor.
Start car, and run through all gears to pressurize hydraulic shift control system.
Stop engine.
Drain transmission, and temporarily reinstall drain plug.
Remove transmission dipstick.
Remove plug from Line inspection port.
Use small blow gun with pointed rubber tip to blow compressed air into the line inspection port until you hear air bubbling up through fluid in transmission for a moment.
Drain transmission again.
Use tube brush or similar to try to remove as much junk as you can from transmission housing, and from under transmission oil filter (just inside drain port, and to the right).
Reinstall drain plug with new washer.
Refill transmission (you'll need to use about 4.25 quarts used of 3).
Start engine, run through all gears, stop engine, and recheck fluid level.

I did this last week and my transmission was about 95% recovered! My only problem was that 1st gear would drop out, and re-engage sometimes when I was in M1 to descend a hill, or starting from a stop after the transmission was warmed up. I did my reverse-flush again yesterday, and my tranny seems to be 100% fixed!

I'll post an update later if you want to find out how it holds up.

 

good job done. very well written, thank you. now I know how I can do mine in the future if it does what your trans did.

 

I would suggest doing it preventively once or twice before you have problems. A transmission guy on another forum says my fix might not last due to damage done when my tranny last oil pressure.

So far, it's working great, but this guy has me paranoid.

I'd also suggest limiting the air pressure you blow in to about 45-50 psi, just to make sure there's no chance of damaging the filter.

 

I just chatted with my mechanic about this and he says I should probably be fine. Part of it is because I got a lot of junk out, and didn't put it back in. Part of it is also that CR-Vs can be flat-towed for up to something like 300 miles an a time. Obviously if you flat-tow one of these, you're going to be spinning half the transmission with no oil pressure the whole time.

My mechanic does not recommend flat-towing any automatic, but he has other customers that do it, and they don't seem to have trouble. Also, I can't imagine Honda would recommend something in the owner's manual if it's likely to ruin parts.

 

the 2018 owners manual states it is not recommended to tow your vehicle behind a motorhome. refer to emergency towing. keep the drive wheels off the ground.

 

Thanks so much for the post and update,I'm having shift problems with my 2000 Accord,I may try this,thanks.