JeffKrav

Hi, I am Jeff and new to this Forum!

I have a 2002 ES300 that is showing code P0776-transmission pressure solenoid switch, stuck off? Everything has been fine except some belt noise/slippage lately. We were traveling home and the vehicle lost all power to the transmission, engine runs fine.

Checked the code and the vehicle was in "safe mode". We reset the code and car operated normally for a while, and then went back into safe mode.

My questions are: 1) is this just a computer reset problem? 2) do I need to replace the solenoid switch? 3) Where is this switch located (pictures would help).

Any advice would be greatly appreciated!

Thanks!

hzt30

How is your transmission fluid?

P0776:
Possible causes
- Faulty line pressure solenoid B valve
- Line pressure solenoid B valve harness or connectors
- Line pressure solenoid B valve circuit is open or shorted
- Low transmission fluid level
- Dirty transmission fluid

When is the code detected?
The gear required by the Engine Control Module (ECM) does not match the actual gear when driving
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Transmission shift shock
The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in response to a signal sent from the Transmission Control Module (TCM).

If you reset the ECU and the code came back then a reset did not work.

Usually the solenoids are located in the valve body. Drop the transmission pan and you will see them.

You can check the solenoids with a multi meter. Maybe the valve is just stuck.

JeffKrav

The transmissin fluid is full and clean on the dip stick, although we have never had it flushed.
Yes, the reset only worked for a short time, then the symptoms came back.

We can try dropping the pan and checking the solenoids - thanks.

JeffKrav

How difficult is it to replace the transmissin with a used one?

hypervish

How many miles on the car? Has the fluid ever been changed?

I wouldn't recommend going more than 30k miles on Toyota Type-IV without doing a drain and fill.

Road Rage

Hang the engine, drop subframe, remove axles, drop tranny. Shorthand version anyway.

JeffKrav

171,00 miles

To my knowledge the fluid has never been changed. We bought this used.

JeffKrav

Does this sound like a fluid problem, solenoid problem, or something else? When we clear the codes the tranny runs normally until the code reapppears and puts the system into safe mode/

Thanks

Road Rage

Most likely a solenoid problem, in fact I've never seen that code NOT be a solenoid problem.

hypervish

I agree, that it's likely a solenoid issue.

But, it is not a good thing that the fluid hasn't been changed. You should do a drain and fill at least every 30k miles using Toyota Type-IV.

hzt30

I usually drain the transmission fluid every other oil change. Just remove the drain plug and let it drain then add the same amount of fresh fluid that was drained. Then every 25,000 miles I drop the pan and do a complete fluid and filter change.

JeffKrav

I have also been planning on replacing the serpintine belt due to noise, would that have anything to do with the problem - slippage of a pump?

Thanks again!

JeffKrav

I really appreciate the info - one more question:

How do I locate the correct solenoid? Can I find a picture anywhere?

Thanks again,
Jeff

Road Rage

Here you go, best I can get on a vehicle that old.

JeffKrav

Much appreciated!

Also, about the serpentine belt - any connection? Pump?

Thanks