Automatic not shifting, sometimes

Hello Ray and everyone,

I have a 2005 Infiniti FX35 with rear wheel drive. She (Betsy) has a odd shifting anomaly where she will go about 100 yards, there is a clunk, and she goes into drive, no shifting down. If you stop at a light, then go, you are in drive, not 1st. If I stop, restart the car, it resets and shifts fine. Sometimes it fixes the issue for quite a long time. Sometimes it just refuses to reset. It seems to have ‘no’ pattern, except that at about 50 to 100 yards, it will clunk into drive, in a parking lot, leaving, and wants to stay in drive unless I restart. But… Sometimes, its fine!
Is my car haunted? When the transmission is shifting fine, it shifts AH MAY ZEEEEN! Then sometimes it just stays in drive. Very slow on drive-aways.

Bill… of the giant gray eyebrow people.

Is the Check Engine light on?

And when was the last time the transmission fluid was serviced?

Tester

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Hello,

I changed out the oil last year when this had started. I hoped that was the issue. It didnt fix it.
It has a check engine light concerning the transmission,
Newest Codes;
P0717…Turbine Sensor not connected or poor connection
P1764…The Direct Clutch Solenoid Valve
P1762…Direct clutch solenoid valve is controlled by the Transmission Control Module (TCM)

Many were saying that it was actually a faulty turbine RPM sensor causing the faulty report to the computer. I had that changed. Pricey as they have to separate the trans casing to get to it. That is part number 31935-1XJOD (I thinks thats a letter ‘oh’ in there). Also called 20201007.

And oddly, it all resets when I restart the engine, and sometimes it works fine all day, which leads me to believe its totally electrical.

I’d guess your transmission harness has an intermittant short to ground. A restart resets it, vibration makes it come back. The harness going to the turbine sensor and direct clutch solenoid is the likely source.

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I concur w/MM above, seems more likely a faulty electrical connection problem than a faulty part. The pertinent electrical connection could be inside the transmission though. A basic battery/charging system test is where I’d start if I had that problem. Next up would be to verify that the transmission ground (i.e. the transmission case) was securely connected to the chassis ground.

Note: It may confuse your mechanic When you say it “clunks” into Drive 100 yards from when you start driving. “Drive” just means the transmission is engaged and moving the car. It doesn’t imply which gear is beign used. As you are able to drive 100 yards before hearing the clunk, Drive is already engaged at that point. Maybe in first gear, but that’s still Drive. How many gears are shifted through before the final gear depends on the car. My truck has a 3 speed automatic, and it starts in first when I first select D, then at about 10 mph it shifts to second, and about 25 mph it shifts to third. It doesn’t make any clunking sounds though at the shifts. Just a little bit of a jerking sensation.

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Mine has 3 speeds also. 1st is first gear when in Drive at a stop, but then it switches to drive selection, 3rd gear, after a while.

Thanks George.

Interesting. Many thanks, MustangMan.

You have a 5 speed automatic transmission .

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+1
The last US-market vehicles with a three-speed automatic transmission were from the 2001 model year, and they weren’t luxury vehicles. Luxury vehicles–like the OP’s Infiniti–gave up on automatics with only three speeds many years before that.

My last 3 speed was in my 81 olds. Now it’s 4 an 6 speeds. I have to watch the tach to check shifting on the 6 speed.