Help with transmission replacement recommendation

[GeauxMudding]

I’m not sure if this is the right place to ask for help but looking for some input and advice from my Mud brethren.

I have a 2013 Land Cruiser with 172,xxx miles. Have had little to no issues with her since I got her (8 years and 80k miles ago). To be clear, I have done all typical maintenance, changed an alternator, water pump, and radiator.

Last week I had the infamous check engine light, 4Lo (flashing) and Trac Off display on the instrument panel. I tried a couple of simple fix things I’ve read about before (specifically tightening fuel cap and checking the battery connection) but nothing truly mechanical.

I immediately took it to my local Toyota dealership. They hooked her up and said it was flashing a “speed sensor code” and ordering and replacing Part# 89413-0c021 would fix it. They ordered the part and did the work. I picked the car up the next day, drove it around town (about 40 miles of driving) with no issues.

The next morning on my way to work, same check engine, flashing 4Lo, and Trac off display within the first 2 miles of driving. I immediately took it back to the dealership and they checked it out. The tech told me it was “wired incorrectly” and they had fixed the issue. I picked her up on Friday, drove her home (about 7 miles) and no issues. Parked her for the weekend. Got in this morning and same check engine lights came on.

This morning I took her back to the dealership and I just got a voicemail from the Toyota dealership saying they took a look and recommend a full transmission replacement!

I’m not mechanically inclined enough and will be getting a second opinion but asking, does this seem feasible? Has any one heard of this quick of an escalation from a speed sensor replacement code to a full transmission replacement?

I have experienced no issues driving it? I’ve had a transmission go out in a different vehicle and could tell there was an issue. I have experienced nothing like that with this vehicle (even when the check engine light came on the past week) and am shocked that this is the recommendation.

Sorry for the long post and thanks for the opinions, just hoping to get some feedback before getting a second opinion from a different dealership/mechanic.

 

[PDoyle]

How old is the battery? Find a Toyota Indy by you and have them check it out. Has it been in wet weather recently. Check your sunroof drains. Check the carpet for any wet areas.

 

[GeauxMudding]

Thanks for the response!

The battery is about 6 months old (alternator is a couple of months old. Wet conditions hasn’t been atypical - highway driving in rain events (heavy rain a handful of times the past couple of weeks). Haven’t checked the sunroof drains yet. Will do that.

I’m in Atlanta area and was going to take it to a Land Cruiser mechanic I’ve worked with on my FJ in the past.

 

[Killacaviar]

I don't really have an answer for you but I would 100% get a second even third opinion, if you don't have a good relationship with a reputable shop yet. From what I can recall, there have been very few transmission failures/replacements round these parts and the ones that did experience it had a handful of operational symptoms outside of a few codes.

 

[bloc]

Not a typical failure, but not impossible either. It is plausible that the speed sensor code was actually an issue with the transmission all along.

But yes I'd want a second opinion. Also we share most of the drivetrain with what's in a Tundra, so if you search online for key words and include those results you'll get a lot more feedback than just what we see from the 200-series in this forum. If you know what the P codes are that'll help a lot in your searching.

 

[linuxgod]

can you get all of the P codes? An output shaft speed sensor error could be transmission related but wheel speed sensor errors would not be.

Typically if you have a transmission failure there are symptoms aside from just the codes - slippage, a failure to properly or correctly engage certain gears, etc. if this happens for instance when shifting into a higher gear and you also notice the engine rev differently then it could be a transmission issue, but it’s much more likely to be something far more minor

 

[Malleus]

^this

I would be very suspicious of that diagnosis, unless there's more you're not describing as the observed driving faults.

 

[Sandroad]

If you’re in the Atlanta area, ACC is a forum supporter and might be able to help with a second opinion.

ACC Garage

www.accgarage.com

 

[GeauxMudding]

The dealership just told me it’s Transmission code p0717. Quick google search says that’s, “Input/Turbine Speed Sensor 'A' Circuit No Signal”.

I have experienced zero issues prior to the check engine and while driving to the dealership after the lights came on.

 

[GeauxMudding]

can you get all of the P codes? An output shaft speed sensor error could be transmission related but wheel speed sensor errors would not be.

Typically if you have a transmission failure there are symptoms aside from just the codes - slippage, a failure to properly or correctly engage certain gears, etc. if this happens for instance when shifting into a higher gear and you also notice the engine rev differently then it could be a transmission issue, but it’s much more likely to be something far more minor

Thanks. There haven’t been any slippage or shifting issues. I think it’s a bad/lazy diagnosis. At least that’s what I’m hoping!

 

[linuxgod]

I can’t print the PDF from my phone so I think images will be missing with just a copy-paste but this is the diagnostic for that code.

​

DESCRIPTION​

This sensor detects the rotation speed of the turbine which shows the input revolution of the transmission. By comparing the input turbine speed signal NT with the counter gear speed sensor signal SP2, the ECM detects the shift timing of the gears and appropriately controls the engine torque and hydraulic pressure according to various conditions. As a result, the gears shift smoothly.

All the conditions below are detected for 5 seconds or more (1-trip detection logic). (a) Gear change is not performed. (b) The gear position is 4th, 5th or 6th. (c) The T/M output shaft rpm is 1000 rpm or more. (d) NSW switch is OFF (e) R input signal is OFF (f) Transmission range switch fail (P0705): Not detected (g) The T/M input shaft rpm is 300 rpm or less.

Open or short in speed sensor NT circuit Speed sensor NT ECM Automatic transmission (clutch, brake or gear, etc.)

Reference: Inspect using an oscilloscope.
Check the waveform of the ECM connector.

Standard: ​

1 V/DIV., 2 msec./DIV.

Engine idling (shift lever in P or N)

MONITOR DESCRIPTION​

This DTC indicates that a pulse is not output from the speed sensor NT (turbine (input) speed sensor) or is output only a little. The NT terminal of the ECM detects the pulse signal from the speed sensor NT (input RPM). The ECM outputs a gear shift signal comparing the input speed sensor NT with the output speed sensor SP2.
While the vehicle is operating in the 4th, 5th or 6th gear position with the shift lever in D, if the input shaft revolution is less than 300 rpm*1 although the output shaft revolution is 1000 rpm or more*2, the ECM detects the trouble, illuminates the MIL and stores the DTC.
HINT:

• *1: Pulse is not output or is irregularly output.
• *2: The vehicle speed is approximately 50 km/h (30 mph) or more.

MONITOR STRATEGY​

Related DTCs	P0717: Speed sensor (NT)/Verify pulse input
Required sensors/Components (Main)	Speed sensor (NT)
Required sensors/Components (Related)	Speed sensor (NC)
Frequency of operation	Continuous
Duration	5 seconds
MIL operation	Immediately
Sequence of operation	None

TYPICAL ENABLING CONDITIONS​

The monitor will run whenever the following DTCs are not stored	P0705 (Park/neutral position switch circuit) P0751, P0973, P0974 (Shift solenoid valve S1) P0756, P0976, P0977 (Shift solenoid valve S2) P0761, P0979, P0980 (Shift solenoid valve S3) P0766, P0982, P0983 (Shift solenoid valve S4) P0748 (Shift solenoid valve SL1 circuit) P0776, P0778 (Shift solenoid valve SL2)
Shift change	Shift change is completed and before starting next shift change operation
ECM selected gear	4th, 5th or 6th
Output shaft rpm	1000 rpm or more
NSW switch	OFF
R switch	OFF
Engine	Running
Battery voltage	8 V or higher
Engine switch	On (IG)
Starter	OFF

TYPICAL MALFUNCTION THRESHOLDS​

Speed sensor signal rpm

Less than 300 rpm

COMPONENT OPERATING RANGE​

Speed sensor signal rpm

300 rpm or more

WIRING DIAGRAM​

INSPECTION PROCEDURE​

NOTICE:
Perform the universal trip to clear permanent DTCs
1. DATA LIST
HINT:
Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.
NOTICE:
In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.
(a) Warm up the engine.
(b) Turn the engine switch off.
(c) Connect the Techstream to the DLC3.
(d) Turn the engine switch on (IG).
(e) Turn the Techstream on.
(f) Enter the following menus: Powertrain / Engine and ECT / Data List.
(g) According to the display on the Techstream, read the Data List.

Engine and ECT​

Input shaft speed/ Min.: 0 rpm Max.: 12750 rpm

Lock-up: ON (after warming up engine): Input turbine speed (NT) equal to engine speed OFF (idling with shift lever in N): Input turbine speed (NT) nearly equal to engine speed

The data is displayed in increments of 50 rpm.

HINT:

• SPD (NT) is always 0 while driving:
  Open or short in the sensor or circuit.
• SPD (NT) is always more than 0 and less than 300 rpm while driving the vehicle at 50 km/h (30 mph) or more:
  Sensor trouble, improper installation, or intermittent connection trouble of the circuit.

PROCEDURE​

INSPECT SPEED SENSOR NT INSTALLATION

(a) Check the speed sensor NT installation. OK:​ The installation bolt is tightened properly and there is no clearance between the sensor and transmission case.​

INSPECT SPEED SENSOR NT

(a) Disconnect the C41 speed sensor connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance: ​

CHECK HARNESS AND CONNECTOR (SPEED SENSOR NT - ECM)

(a) Disconnect the C53 ECM connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance: ​

C53-124 (NT+) - C53-123 (NT-)

C53-124 (NT+) - Body ground

C53-123 (NT-) - Body ground

 

[linuxgod]

I can get a full PDF for you later if you’d like. Assuming that code is correct I’m guessing they tried to just replace the sensor but it still threw the code again. It could be a slipping shaft, but it also could be a wire that is frayed and shorting out, or a misaligned sensor, or a number of other possibilities. I wouldn’t jump to a $6k transmission replacement just yet.