Vehicle Speed Reads 255 km/h on DATALIST, throwing codes P0717 and P0793

[Ndomano]

I'm repairing Toyota Harrier ACU# (Automatic transmission) with no reversing problem. When gear is shifted to R she throws codes P0717 (input speed sensor A no signal) and P0793 (Intermediate shaft speed sensor no signal) and she does not enter in reverse gear. Oddly enough when reading live data (used both Toyota techstream software and Autoboss V-30) I see vehicle speed is 255 km/h but the vehicle is stationary



WHAT I HAVE TRIED SO FAR
1)I changed the Complete Automatic transmission and made sure AT fluid is on required level but no luck


2)I checked input shaft speed sensor and intermediate speed sensor but they are all okay, even tried to replace them but problem persists


3)Then I thought maybe ECU is faulty coz of the odd vehicle speed value I was getting and decided to replace the ECU but no luck


4)Inspected solenoids but they are all okay.


Currently I'm thinking may be due to ECU recognizing vehicle speed of 255 km/h(though vehicle is actually stationary) it forbids AT to shift Gears(shifting gears at that speed is dangerous and may kill the AT). But my assumption leaves me with un-answered qns like WHERE DOES THAT VEHICLE SPEED OF 255 KM/H COME FROM WHILE VEHICLE IS STATIONARY?


I tried disconnecting ABS ECU and the Wheel speed sensors But the vehicle speed still reads 255km/h on DATALIST


If ECU was faulty then why even after replacing the ECU I still got Vehicle speed of 255km/h
Those are just my ideas, can you guys help me how to fix this issue please

[Jasko93]

Hello 255km/h is a max range so you have open circuit or short in sp signal wire to combination meter.

look this : http://zatonevkredit.ru/repair_manuals/raw_content/AWHn1ujOBFyj9RK3jwBu

[Meat-Head]

Sounds like both sensors lost earth

DO AT YOUR OWN RISK

if inductive sensors, short one at a time to earth see what computer say

[autotrans]

what year is the vehicle and is it a jap import

[Ndomano]

Sir thanks for suggestion but there are 2 thing here
1)Speed I read from my speedometer and
2)Speed I read from techstream's datalist and Autoboss v-30

1 is correct but 2 is wrong value. So the value I read on a combination meter is correct(when car is stationary it's 0) but the value from data stream is 255

[Ndomano]

what year is the vehicle and is it a jap import

It is Toyota Harrier ACU#, I do not know the exact year but as per chasis info it's between 2006 and 2012, and yes it's jap import

[Jasko93]

I think 255 in data list if combination meter lost communication from ABS/VSC and you don't see it in dash because dash need signal waveform to work it can make you problem. It's 1 wire communication ABS/VSC > Combination Meter > Engine ECU, do you have any other DTC in this three ECU?

[autotrans]

A few years ago we had Toyota auto in the workshop, driving reasonable but late changing gear right across the range
no fault code's. wasted a lot of time checking out throttle pots sensors ect, while out on road test I noticed the speedo
was reading 40 and launch was reading 40 but one was KPH the other MPH. this was a jap import with some gizmo
behind the dash to do the conversion KPH to MPH, the tcm took the vss signal after conversion. Not quite the same
problem I know but certainly a good place to start looking

[Ndomano]

A few years ago we had Toyota auto in the workshop, driving reasonable but late changing gear right across the range
no fault code's. wasted a lot of time checking out throttle pots sensors ect, while out on road test I noticed the speedo
was reading 40 and launch was reading 40 but one was KPH the other MPH. this was a jap import with some gizmo
behind the dash to do the conversion KPH to MPH, the tcm took the vss signal after conversion. Not quite the same
problem I know but certainly a good place to start looking

I think you are among the few who managed to understand my problem correctly, I also experience the same issue and I have tried a lot of options with no luck. I will inspect the overall system to see if there's such an issue

[drnd]

Manufacturing Year..?

Sent from my TA-1053 using Tapatalk
Your speedometer display reading is ok then communication is ok between ABS and meter cluster.so check meter cluster out signal(4p) to tcm and ecm

[Ndomano]

A few years ago we had Toyota auto in the workshop, driving reasonable but late changing gear right across the range no fault code's. wasted a lot of time checking out throttle pots sensors ect, while out on road test I noticed the speedo was reading 40 and launch was reading 40 but one was KPH the other MPH. this was a jap import with some gizmo behind the dash to do the conversion KPH to MPH, the tcm took the vss signal after conversion. Not quite the same problem I know but certainly a good place to start looking Sir I checked and verified it's exactly the same issue with my vehicle, coz there are connectors behind the dash when they are removed speed reads 0 on datalist. May I know how you solved that GIZMO thing, did you change the cluster or there some modifications you did on the dash?

[autotrans]

I just bypassed the GIZMO and proved the vehicle changed gear as normal, but as the vehicle belonged to a tight arse
motor trader who did not like to pay for anything, I handed the vehicle back and told him to sort his speedo out

[Ndomano]

I just bypassed the GIZMO and proved the vehicle changed gear as normal, but as the vehicle belonged to a tight arse motor trader who did not like to pay for anything, I handed the vehicle back and told him to sort his speedo out Okay sir, thank you

[autotrans]

any names or numbers or id on this gizmo, the one I did was a few years ago, from memory it just had four wires
power \ ground \ sig in \ sig out \ and a adjuster