Help Please , Civic 8th Gen Weird odometer Problem

[kawafan]

Simple :

odometer Shows Wrong Reading car on 100 and it shows 20, Already changed VSS , What to do Next ?

Details:

Hi
i bought a Civic 2007 Vti Oriel , its Manual Transmission , the Car it self in very Good condition and everything is its in original state, but i have a weird odometer problem ,

i have phone with GPS speedometer , I can see when i am on 100 k/h , but the car show only 20k/h ,
when i am on 20 kph on fone , it on 1-2 kph , mean it runs slow .
i had also tried this with my friend car and both car on 100 kmph and the car odometer shows only 20-30 .

so. i read on internet that it might be VSS problem the speed censor . so i purchased the VSS from Honda shop and changed the car vss but the problem same .

so today i visited the electrician and he checked it via the scanner , no major problem found and he says he need to open
car ECU , and Computer and Car Abs system. and he will take 10k labor and will charge additional for the parts .

so what do you guys say what the actual problem could be or should i continue with the electrician.

[usmanulamin]

lol funny problem ... Well, i dont think so that this problem is related to ABS, please be careful, try checking any other electrician as well ... I dont have an idea where the problem could be ...

[rustam54]

Find someone with a basic ELM327 scanner. Many users have them these days.

Then use an OBD software to confirm whether its the same reading on the CAN bus. If no, then your ODO will be faulty or there is some wire shortage to ground.

If yes, then the diagnosis goes further by removing the sensor and simulating revolutions and then observing.

If you are close to wapda town, I can help you with the OBD before you start spending any money

[kawafan]

by chance, my friend have this OBD , its Bluetooth , i have used it once could you please tell me what codes i need to look fo and i will post the result here .

[kawafan]

Hi in torque pro . Same speed shows on phone and odometer . While selecting OBD speed guage.

[rustam54]

Okay. What I can do is post a generic troubleshooting procedure. Actual wire color and connector pin numbers shall be provided as per 8th Gen ESM.

I am not sure that will you be willing to go through all that process but my advise is to ask Honda people to fix it (not some road side electrician). If everything goes as explained, you have to replace your speedo in the end

To start off, the VSS has 03 input wire. Power (12V), Ground (0V) and Signal. (5V or More & Pulsating)

Power is Coming from Fusebox beneath the dash, and the pulse is going to ECU.

The first thing is to check the wiring harness at the VSS and see if all the continuities are okay.

Remove the 3 pin connector at VSS and check for each pin one by one.

Black wire (Ground) should have a 0 resistance to chassis (If not, rectify open wire between ground)
Black/Yellow SHould read 12V when ignition switch is in on( If not, rectify open wire or blown fuse between FuseBox)
BLU/White should read 5V or more when Ignition switch is on( if not, rectify short in wire from VSS to ECU)

Again, these colours may be actually be different for R18

The next step involves reconnecting the VSS connector, tapping in the wires and observe a pulsating 5V in BLU/WHITE wire as the vehicle is raised and one wheel is rotated while blocking the other.

Finally this pulsating signal is verified at the Instrument Cluster (Odo). Again the actual pin number shall come from ESM.

If all goes okay, sadly you;ll have to replace your Odometer.

[rustam54]

Hi in torque pro . Same speed shows on phone and odometer . While selecting OBD speed guage.

Yes the app Torque reads from the same OBD codes. If its showing same as odo, I am pretty sure that the pulses are not read properly by the ECU and Odometer. And the odds are pointing a problem with wiring.

[kawafan]

Hi
After spending much time with 3 different electrician , the final Output was , the E​CU of the Car was Changed , it is a Manual Car and ECU was JDM Honda , Automatic , that's why it is showing the wrong speed , yes it sound stupid but we checked from 3 different electrician , they tried scanner and it give the codes of Automatic transmission , so end result was bought ECU from Bilal Gunj around 40k and 5k for electrician for programming and labor , and now odometer shows correct speed.

just posting if it can help someone else in future.