P0745 transmission solenoid

[fsbaksh82]

Hi
SES light came on with P0745, line pressure solenoid vault. My car is shifting hard especially from neutral to drive, and also jerks when driving slow. Is the solenoid going bad and needs to be replaced, it has 180K miles (2001 I30). How much work is involved? What else should I look for? What are your experiEnces with this? Thanks

[maxhopper]

I would check the drop resistor first. It is on the driver side strut tower. Make sure that is plugged in and there is no damage to the wires.

See here starting on page AT-166. http://www.nicoclub.com/FSM/I30/2001/at.pdf

[srwood11]

This seems to be a common problem with the I35's. I ended up fixing it (for now) in the process of troubleshooting. I believe it was stuck because of failure to change the transmission fluid by the previous owner (I had not yet serviced the transmission since purchasing). In mine (2004 I35), it was throwing the P0745 code, and shifting hard between 1st and 2nd.

I started following the troubleshooting steps in the FSM. I checked the drop resister first, and it was good - 12 ohms. Next I dropped the transmission pan and tested the line pressure solenoid value. This is easy to do. The value is on the opposite side from the set of shift valves. The inside harness unclips easily from the connector where it enters the sealed transmission area.

I checked the solenoid valve resistance on Pin #4. It was good. 2.5 to 5 ohms range.

Then, also using pin #4, I applied 12 volts from a small batter charger. I applied on and off about 12 times and listened for the clicking sound each time. All sounded good, but unknowingly, this apparently freed up the stuck solenoid. Based the schematic, the current flows through the dropping resistor. I think that applying full current from the charger freed up the solenoid.

I didn't have time to proceed with the remaining steps, so I put it back together, and gave it fresh synthetic transmission fluid with a bottle of Lucas transmission conditioner. I haven't had a problem since (been over a month).

[fsbaksh82]

It was the drop resistor. I bought it for around $20 and that fixed it! It has been 3 months and no problems.

[Baby]

fsbaksh82,
Where did you get the drop resistor for $20. My dealer wants $80
Thanks

[Jrcash1010]

Does a 2012 rogue have a solenoid drop resistor? I have looked but dont see one.
Thanks

[VStar650CL]

Does a 2012 rogue have a solenoid drop resistor? I have looked but dont see one.
Thanks

Nope. Whole different animal, all the Rogues have CVT's and not A/T's. Yours has an RE0F10A made by Jatco.

P0745 is an electrical hard code meaning there's a problem in the line pressure solenoid coil or wiring. The TCM on your Rogue is separate from the transmission (behind the battery), unlike the TCM's on most Nissan axial A/T's which are inside the pan. First thing to check is make sure a rodent hasn't munched on any of your engine box wires. If you don't find any wiring issues then you'll need a new Valve Body. You can't replace individual solenoids like you can on an A/T, because it will throw off the electrical profile of the solenoid (what Nissan calls "IP Characteristics") and the transmission probably won't work right. When a new VB is installed, there's a procedure you can do using the CVTz50 app to load the IP's from the new VB to the existing TCM.

You can find diagnostics for P0745 on TM-75 here:
https://www.nicoclub.com/service-manual ... 2%2FTM.pdf

[Jrcash1010]

Mine has the p0746 code.I have replaced the valve body. Then found that the reworked one was wired for the dodge model. Both old and new solenoids read good. Put new solenoids on old body. Replaced speed sensors and both filters. Still getting p0746 and wont move in reverse or drive. Shifts into gear smoothly but wont move.

[Jrcash1010]

I will check the wiring now though because I bought it from someone to fix and there is evidence rodents were under the hood.

[VStar650CL]

Putting new solenoids on the old body was a bad idea, now the IP Chars are unknowable and it may never work right. The problem is, the solenoids on a CVT aren't "on-off" switches like an A/T. They're variable flow governed by PWM, and if the TCM doesn't know how much PWM equates to how much flow, proper operation is f#cked.

That isn't the worst news. P0746 isn't a hard code, it's an "incorrect ratio" performance code which almost always means the belt is slipping. If fresh fluid didn't eliminate it, then chances are your belt and pulleys are shot. This bulletin is for the later '10D's which have replaceable belt-and-pulley sets, but the pics of belt damage are valid for your '10A. If you find a scuffed belt, quit throwing money and time at it, the tran-ny is toast and you won't save it.
https://static.nhtsa.gov/odi/tsbs/2019/ ... 8-0001.pdf