Well, red is a good sign. Lots of times a good flush and filter change solves the problem, but not here I guess.
RPM at 70mph
- Thread starter Kalispel2230
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
bloc
SILVER Star
Whatever you find, please keep us posted. This kind of stuff helps the collective knowledge base here a lot.
Good luck with it.
Good luck with it.
- Thread starter
- #23
Hello, well.... I just completed a 100 mile drive in the LC and all went well. RPM's were 1600-1700 at 70mph on flat dry ground on the freeway. No lights flashing on the dash, no trouble codes appearing, no hard shifting in the gears, she ran like a new vehicle.
So the great mystery is to figure out what is going on. Hopefully Toyota can give me more than "You need a new transmission" when I see them on Saturday. I appreciate the responses to my query.
So the great mystery is to figure out what is going on. Hopefully Toyota can give me more than "You need a new transmission" when I see them on Saturday. I appreciate the responses to my query.
Maybe an ECU reset cleared whatever code was stored and causing the vehicle to run in limp mode?
- Thread starter
- #25
Toyota did the ECU remap. I drove it 140 miles and the VSC, Check Engine, and Trac Control lights came on and were steady. The 4lo light came on blinking. I disconnected the neg. battery cable for a minute and everything appeared to be reset. The DTC's I listed earlier came up after the remap of the ECU. The service manager thinks a new transmission will probably be necessary, but doesn't know when my current transmission will fail me since it seems to work ok(at least for now). I just don't want to replace the transmission if it's actually ok and it's some electrical problem causing the warning lights to come on. I'll just keep researching and trying to learn about this and hopefully come out on top.
Would be funny if the VSS was just off. Here... I'm on the highway cruising at 70mph and 4000rpm, and man, I am just FLYING. Sounds like it could be a few sensors sending goofy signals. 4000rpm sounds pretty eventful from the v8.
I'm not convinced it's the transmission, but I'm not an ASE-certified mechanic either. When I've had transmissions go they tend to slip at low RPM first before they engage... or really anywhere. If the transmission feels tight, I would seriously look for an electronic issue - either sensors or wiring. Any evidence of mice chewing on wiring?
BTW 4000 RPMs at 70mph sounds like you're stuck in 3rd gear... I run at 3000 RPMs at 70mph when towing in 4th.
Driving around at 4k RPMs while not ideal and will hurt gas mileage, it will definitely not damage the engine.
While not ideal and detrimental to gas mileage, driving at 4k rpms will not damage the engine. It would take a looooong time for anything noticeably negative to happen to the engine as a result of driving that way.
Not my cup of tea.
- Thread starter
- #31
I just finished driving 70 mph on the highway and the tach was showing 4k RPM again. I reset the DTC's while driving that speed and the tach fell to 1700 RPM. The engine didn't change rpm's so something is going on with the tach to give the false reading. The DTC's that keep popping up are B1866 battery power supply ECU circuit short to battery , P0761 Shift solenoid "C" performance , and P2714 Pressure control solenoid "D" performance/stuck off. I'm not sure what all of that means, but I'll keep looking into it.
Stupid question but... the tach fell to 1700 rpm. How did the engine sound ? Was it ever over reving ?
Sounds like you at least escaped buying a new transmission.
Sounds like you at least escaped buying a new transmission.
- Thread starter
- #33
It wasn't over revving, it sounded normal.
OK.
I missed the point of the thread. I read the first post thinking the engine was actually running 4K.
So I will just crawl back in to my hole ...
I missed the point of the thread. I read the first post thinking the engine was actually running 4K.
So I will just crawl back in to my hole ...
gaijin
GOLD Star
Now I'm lost. So at first you wanted to know if 4K RPM was normal. At that time, did 4K RPM sound normal? Now, when the tach reads 1700 RPM it sounds normal.
Didn't you know at first, since it sounded normal, that the 4K RPM tach reading was wrong? There's a big difference between 1700 and 4K RPM
- Thread starter
- #36
At first I was going 70 mph and the engine sounded normal, it didn't sound like it was revving high. I glimpsed down at the tach and saw 4k rpm and I thought that was awfully high(but the engine sounded as it should in my opinion even though the tach was showing 4k rpm). So I asked on here what people normally have for rpm at 70mph. Later, I bought a FIXD reader and cleared three DTC's I was getting and then went out driving. At 70 mph I was showing 1600-1700 rpm on the tach. That was more to what everyone else was showing on their tachometers for going 70 mph on a dry flat surface and so I believed clearing the DTC made my tach work properly where it was originally way high. Today I went out driving and I was going 70 mph and I noticed my tach was again showing 4k rpm, but the engine sounded normal as when the tach was showing 1700 rpm when going 70 mph. I cleared the three DTC's that were showing again, while I was driving, and I noticed the needle on the tach fall from 4k rpm to 1600-1700 rpm. So the DTC's that keep appearing are causing the tach to show an erroneous number until I clear them out. I was recently at Toyota and they told me I probably needed a new transmission from the DTC's that were appearing. They agreed that the transmission felt tight, wasn't slipping, didn't make any weird or abnormal sounds. I am returning to Toyota this Saturday to talk about these problems and I didn't want to immediately jump to replacing a transmission when it seemed to be working, even though I'm getting the various DTC's. I'm just doing some troubleshooting here because i'm not sure why my vehicle computer is putting out the 3 DTC's regularly. Did that help clear things up any? I know I'm currently at a loss on this.
- Thread starter
- #37
The 3 DTC's that keep reappearing are: B1866 battery power supply ECU circuit short to battery , P0761 Shift solenoid "C" performance , and P2714 Pressure control solenoid "D" performance/stuck off.
32cls6speedmt
SILVER Star
Three quarts low of atf. That is a lot of fluid unaccounted. Seems like a drain but someone forgot to refill.
- Thread starter
- #39
Possibly. The Toyota folks told me they hadn't see one 3 quarts low before. Especially with no indicator of a leak anywhere. The vehicle is a mystery at this point. Hopefully I can fix the problems without going broke!!! 
For what it’s worth, I recently battled a transmission issue with my 07 Silverado’s Allison transmission. I had driven the truck from Seattle to Eastern WA, next morning, truck was all of the sudden stuck in first gear. To preface, I hadn’t experienced any other transmission issues, everything had been flawless the night before. Scanned codes, result was shift solenoid “E” stuck on. The first thing I learned through this process is the generic description of the code doesn’t always align with the actual naming of the shift solenoids in your specific transmission, but that may just be an Allison thing. There are multiple speed sensors on the Allison and the values are compared to monitor transmission health, I’m assuming our Toyota’s are the same way. Grasping at straws: I wonder if there’s an issue with one of your “speed” sensors, causing the strange RPM readings and possibly triggering sympathy codes related to the shift solenoids if it thinks there’s an issues (clutches slipping?) based on an intermittent faulty speed(rpm) reading? While I was only dealing with one code in my situation which correlated to the solenoid, the solenoid itself was not the problem. The problem was one of the actual valves in the body was sticking. If any particulate finds its way in the valve body, it can obviously mar the valve and prevent it from actuating correctly (transmission was due for a flush and filters). I ended up replacing the entire valve body which thankfully fixed my issue. I can certainly sympathize with your situation and I hope it’s something trivial that doesn’t require a new transmission.
Best of luck,
Joe
Best of luck,
Joe
