Omar4589

First off, I’d like to apologize in advance if I am posting this in the wrong section. This is my first time posting.

My car’s SES light turned on last night & I got the code P1769 from it this morning at Autozone.

P1769 - A/T HLR/C Solenoid Valve Circuit Malfunction

I’m wondering if anyone else has gotten this code before and what the fix was in that particular case.

As I started to drive away from the gas pump last night, I heard a low sound and felt my car lose power a bit. I was only driving maybe 10mph max to the edge of the street entrance. (Again, I was driving out of the gas station). Once I started to enter the road, I naturally pressed on the gas pedal to accelerate. My car felt like it had lost power. It accelerated rather slowly and it was also slow to change the gear. THEN the SES light came on. It honestly scared me so I started driving “slowly” (30-40mph) till I could stop. I stopped and popped the hood with the car on but I didn’t hear any unusual noises & still don’t. I turned the car off and back on & drove home.

The car feels normal this morning I guess. Maybe it’s in my head, but I feel like it has lost a little power. The SES light is still on & that’s the code I got from autozone right now.

One thing to mention, (I don’t know if it’s related, but it could be) about 2-3 days ago, I started to hear this loud clunk/knock sound right before I start the car. It’s a one second, one time sound that happens when I turn the key to the “on” position. I don’t hear any unusual sounds when I turn it to the “start” position or once the car actually turns on.
It only happens when I turn it to the “on” position & it usually only happens when the cars been sitting for a few hours. It doesn’t happen if it’s only been a few minutes that the cars been off and I turn it back on.

i never had any issues with my other 2 Zs, so this is my first time seeking help with something like this. It’s hard to trust mechanics around here, so I thought I’d do my own research first to see if I can figure this out & save myself some money.

My car is a 2005 Nissan 350Z Convertible. Automatic Transmission. 98,00 miles.
I’ve had the car for a month now. Recently bought it off an older gentlemen who just had it parked outside. It had been sitting for about a year and half. The only things Ive had to replace were the battery & the left cam shaft position sensor. I did that the day I bought it, & it cleared the SES light. The cars driven great till now. Now I have this problem.

thank you in advance for any comments or questions.

- Omar

Omar4589

Drove the car around a bit that same day that I got the code from Autozone & everything seemed fine. No slipping or anything was happening. I decided to reset the SES light to see if it would come back on. I guess that would reassure me that something’s not right , even if the symptoms have gone away.

Today the slipping started again and a lot more pronounced. The RPMs would hit the 4000 range and the car wouldn’t move. I only let it jolt once before I stopped. Luckily I was by a big parking lot, so I drove it around a bit there to see if it got better but it just continued slipping when going from 1st to 2nd to 3rd..etc. Parking, neutral, and reverse work fine. The loss of torque is on drive. Turning it off and on seemed to help as the 4th and 5th gears actually kicked in after I did that. SES light came on. Drove home slowly and decided that I’m gonna start by replacing the transmission oil & filter. I added some Lucas slip stop too. I’m PRAYING this helps. The SES light is still on.

I’m going to drive the car around a bit and hope the new fluid, filter, and additive help. From what I’ve heard, I need to drive the car a bit for it to kinda clean itself.

If the problem persists, my next step is to check the connections that go in the transmission. Cleaning the pins and checking for shorts. Doing that because of the “circuit malfunction” part on the diagnostic code.

If that’s not the culprit, then I guess I will have to remove the valve body assembly to check the solenoids and stuff.

Been learning a lot lately while researching this problem, but I’m still doubting myself. Thing is that I would rather fix the broken part than replace the whole assembly or transmission.

I’ll update on Tuesday.

Omar4589

found these in the manual but idk if I know etf I’m reading lmao

im going with the easiest step next which is check the harness connections and stuff

let’s see what happens.

worst case scenario I replace the
valve assembly body. I found a place in SoCal that parts 350Zs so I can get one at a good price from them

Omar4589

This morning (the day after the trans fluid change) the problem still continues. There was a point when the gears wouldn’t engage at all and turning it off and on helped, but the gears are still engaging late.

Going to check the harness connectors tonight & clean them. I doubt there is something wrong with them, but PRAYING it’s just that lol

If not, I’m taking the valve assembly off to inspect the solenoid giving the code & inspect the inside of the TCM.

rodb

Hey! Any luck rectifying the issue and finding a root cause? I must inherited a Z with the same issue and DTC. I've got the valve body off, checking resistant at the solenoid pins, looks as though there are no open circuits. I'd like to pull the tcm cover off to confirm. Any input is greatly appreciated!