# 98 Maxima won't start, error code P0745



## paulesz (Jan 23, 2007)

Any help is greatly appreciated. My 1998 Nissan Maxima hasn't run since Monday of last week when we had a big ice storm (don't know if that's relevant). My car has 157000 miles on it and lately I have noticed that it takes a little more coaxing to get it started. Then on Monday when I went to leave for work it left me stranded at home. Each time I tried to start it the starter would turn over the engine but the motor never started up. 

I began by trying some starter fluid in the air intake but that didn't do anything for me except for cause the engine to backfire as I attempted to crank it. I removed one of the spark plugs and verified that I was getting spark to the cylinder. Then I tested both the front and side crankshaft position sensors and found those to be faulty so I replaced both of them. The car still won't start. I also tested the camshaft position sensor but it looks to be OK. I put a new battery in it, no difference, which didn't surprise me because the battery cranked the starter over all day on Monday without dying on me and I've had it hooked up to a battery charger since then. I checked fuel pump and fuel pressure (all good), I even replaced the fuel filter while I had the line disconnected just in case it was blocked, still nothing. 

Finally I got my hands on an OBD II code reader and when we hooked it up it gave us only one error code: P0745 which is for the Line Pressure Solenoid Valve. My Chilton's manual tells me that malfunction is detected when the A/T control unit detects the improper voltage drop when it tries to operate the solenoid valve. It also tells me to check the harness or connectors (the solenoid circuit is open or shorted) or the line pressure solenoid valve. This is all my Chilton's manual tells me, the only other place in the book that I have found that it mentions the line pressure solenoid valve is on a diagram of the transmission, no where does it tell me how to find it, test it or how to replace it. 

Could the line pressure solenoid valve really be what's keeping my car from starting? If so, does anyone have a Nissan service manual that mentions anything more about this part? Thanks for your help.


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## Jeff (Oct 17, 2002)

I don't see a connection between the code (transmission) and your car not starting.


LudeAEM on Maxima.org said:


> ok here is the deal on this.... I had the same exact problem on my 96. The valves are inside the tranny and i was told by a mechanic that they get clogged sometimes thus causing the hard shifting. The part you need is like $220 but nissan made a "kit" that included the valves, bolts, etc for like $125 or so. I took mine to a dealer because i don't like messing with automatic transmissions. Hope that helps.


See, I don't see it being relative to you engine starting problem.

Are you sure it is getting fuel? Fuel pump turns on?
When was the last time you changed the fuel filter?


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## paulesz (Jan 23, 2007)

I don't see how that error code would have anything to do with my car starting either. When I tested the fuel pressure I did change out the fuel filter at the same time. So unless the problem is in the fuel rail or in the fuel pressure regulator I don't know why it would be doing this. When I removed the spark plug to verify it was firing I could smell fuel in the cylinder, so I really don't think that is my problem.


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## Jeff (Oct 17, 2002)

Sorry, I missed the part about the fuel filter being changed.

Have you checked the wiring to the MAF to ensure it is plugged in?
How did you check the spark plug for fire?...

I'm sure you are doing everything correctly since you sound like you know what you're doing. Just had to ask.

It sounds like something that was gradually going out...which makes me think electrical. (IMO)
Have you checked to ensure all connections are good? MAF, IACV, TBS...etc.
When was the last time you did some good cleaning of the MAF and IACV or EGR?


One last thing...I have heard that the Cam sensor can 'intermittedly' go out. When it does go out, it causes engine flooding (fuel smell on plug).


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## paulesz (Jan 23, 2007)

I ended up bringing my car to the dealership today and I found out what the problem was. It was the Crankshaft Position Sensor that was causing all of the problems. Apparently the sensor has to be aligned properly which wasn't mentioned in my Chilton's repair manual and that’s why it still wouldn’t start after I replaced both sensors. So after paying the dealer $173 to adjust the crank sensor to proper alignment and adjust the idle to idling spec my car now runs. If anyone else has this same problem in the future you might want to take a little more care than I did when I installed the new sensor.


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## brianw (Feb 25, 2004)

$173 to adjust the Crankshaft Position Sensor!?!??!

Holy crap... that's a fifteen second adjustment...


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## paulesz (Jan 23, 2007)

That's the price I pay for not being smart enough to figure it out on my own.


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