Transmission not engaging, codes 0700, 0730, 0740

Hi and thanks for using 2CarPros.

Interestingly, I checked each code and the diagnostic flow charts. The 700 is generic and non specific. The 730 and 740 flow charts contradict each other. Both indicate that if another code is present, it must be fixed before continuing. So, they aren't too helpful. However, I did note that there is one common issue that can pertain to each and that is line pressure. With that in mind, I suggest testing line pressure to confirm it is within the manufacturer's specs. Here are the directions for doing it. The attached pictures correlate with these directions and provide specific directions and technical information.

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TEST

WARNING:
- While testing, be careful of the rotating front wheels.
- Make sure lifts, jacks, and safety stands are placed properly.

CAUTION:
- Before testing, be sure the transmission fluid is filled to the proper level.
- Warm up the engine before testing.

1. Raise the vehicle.
2. Warm up the engine, then stop the engine and connect a tachometer.


picture 1

3. Connect the oil pressure gauges to each inspection hole.

TORQUE: 18 Nm (13 ft. lbs.)

CAUTION: Connect the oil pressure gauges securely; be sure not to allow dust and other foreign particles to enter the inspection holes.

4. Start the engine, and measure the respective pressure as follows.
- Line Pressure
- 1st Clutch Pressure
- 2nd, 3rd and 4th Clutch Pressure

5. Install a new washer and the sealing bolt in the inspection hole, and tighten to the specified torque.

TORQUE: 18 Nm (13 ft. lbs.)

NOTE: Do not reuse old sealing washers; always replace washers.

Line Pressure/1st Clutch Pressure Measurement
1. Set the parking brake, and block both rear wheels securely.
2. Start the engine, and run it at 2,000 rpm.
3. Shift to [N] or [P] position, then measure line pressure.

NOTE: Higher pressure may be indicated if measurements are made in shift lever positions other than [N] or [P] position.


picture 2


picture 3


4. Shift to [D4] position, hold the engine at 2,000 rpm, and measure 1st clutch pressure.

2nd, 3rd and 4th Clutch Pressure Measurement
1. Set the parking brake, and block both rear wheels securely.
2. Start the engine, and run it the engine at 2,000 rpm.
3. Shift to [2] position, then measure 2nd clutch pressure.
4. Shift to [D3] position, then measure 3rd clutch pressure.
5. Shift to [D4] position, then measure 4th clutch pressure.


picture 4


picture 5


6. Shift to [R] position, then measure 4th clutch pressure.

Let me know if this helps or if you have other questions.

Take care,
Joe

I also have a 1997 Honda civic. About 3 years ago I had the same issues as the 1998 has now with the 1997 civic.
I ran the line pressure tests on it and found the average pressure range to be 80 to 90 psi. I believe it should be 110 to 120psi.
I tried to research what in the transmission would cause this issue. I found no direct answers. Seems no one is talking.
I thought maybe the pump gears or housing.
I bought a rebuild kits from OPT that included the metal discs and friction discs and all seals and o rings.
I disassembled the tranny.
Did not find the filter plugged up.
Did find a broken spring at the end of one of the spools and replaced it.
Very little sign of wear if any on pump gears and housing.
Little wear on steel discs not much on friction discs.
Did not replace torque converter.
Put it back together and re installed.
Has same issue. Checked pressures still low and in same range as before.
Swapped out each solenoid one at a time from the 1998 with no change in problem.
I went to the junk yard and bought a tranny and converter install them in the 1997 civic and had no issues since.
I have look all over the net to find out what to replace in the tranny to get the pressures back up to 110 to 120 psi range with no luck. Must be a trade secret.
Any ideas?
If I new I would try another rebuild and replace the torque converter with a rebuilt one.
In the mean time I will run the pressure tests.
I may go to the junk yard and get a tranny and converter Cost is $200.00 if I take it out myself. Add $75.00 if they remove it. How do you know if its good, their answer is Hey it was running when it crashed.

Welcome back:

The transmission line pressure is controlled by a pressure regulator. The regulator valve body is located on the main valve body. The regulator valve body consists of the regulator valve, the torque converter check valve, the cooler relief valve, and the lock-up control valve. I attached a picture of the component. If there is nothing preventing pressure to be low such as dirt, a bad converter, or a bad pump, then that is my first suspect.

Note: When you checked the pump gears, did you measure clearance between them or just do a visual?

Let me know if this helps.

Joe