Speedometer not working

Hi,

Just want to make sure I understand because it is frustrating on your end when I give an answer to something you were not asking so I want to avoid that.

Did you change these two parts in attempts to fix the speedometer not working or did you change these parts and then it stopped working?

Depending on this it will effect the answer. Thanks

Yes, I changed those parts because my speedometer wasn't working and it tells me that I have a bad speed sensor.

Okay. So if you replaced the speed sensors because you had a code, can you give me the codes that you had or have?

Take a look at the attachment. This is the reason I wanted to clarify what the issue was. The speed sensors give the data to the ABS control unit and then it shares the info to the cluster/combination meter over what is called a CAN bus network. This means either the ABS is not getting the speed sensor data (which is why I need the codes) or the ABS is not sharing the info with the cluster or it is not able to because there is a wiring issue.

The code is p1574.

Can a bad wheel speed sensor affect the speedometer?

Because I got under the car and one of the rear wheel speed sensors is broken. I can't plug it in.

Oh. Well that answers it. Yes. This is a speed sensor code and yes, that can cause the speedometer to not work. You have two and if the ECM sees they are not the same then it sets this code and if you are not getting speed sensor inputs then the ABS can't send the signal to the cluster for the speedometer.

We need to fix that sensor and then retest.

So fix the wheel speed sensor and then retest it?

Correct. I suspect that is the issue for the speedometer but there is a chance it is something else. However, that directly effects the speedometer because the ABS sends that signal to the cluster so if it is not hooked up then the ABS cannot do that.

Do you think that can be the problem why the scanner can't communicate with the computer of the car as well?

Can your scanner communicate with any module or just not the ABS? Then have you been able to communicate with the ABS in the past?

A lot of scanners cannot communicate with ABS modules so that may be normal.

This could be a sign of a greater issue but again, the sensor needs to be the first thing then if the scanner is still an issue we can dig into that but I would think the sensor will fix the speedometer issue. In other words, I suspect you have two issues if the scanner can communicate with ABS modules.

It does not communicate at all.

Okay. I assume the sensor will fix the speedometer. Once we get that repaired we can move onto the possible DLC issue or module issue. However, if the speedometer issue is fixed then we will need to start a new post for this issue because we need to keep one per post. People can't find solutions for their issue if they have the same one if it is under a different post.

However, here is a diagram of the DLC. We need to check and make sure you have 12 volts with the key on on pin 16 of the DLC. Then ground on 4 and 5. Then you should have continuity from the DLC to ECM on Pin 7 and 15. If any of these are not correct then you will not be able to communicate with the vehicle. Also, just a dumb question but has this scan tool ever communicated with this vehicle before? I just want to make sure it is not a scan tool issue. If it has, just check it on another car to make sure the tool itself hasn't failed. Seeing if it communicates with another vehicle is the easiest way to do that.

Okay, obd scanner it communicates with my car. but I took my car to a shop and they put the big computer and it didn't want to communicate with my car. I don't know why with my scanner works but not with there's.

That is hard to know. Without knowing what tool they have it is hard to know what they were doing. Assuming they were trying to communicate with even just the ECM, it doesn't make much sense. Unfortunately I don't have an explanation for this without being the one using the tool to see what it was doing.

The only logical thing I can think of is their tool used a different protocol to talk to the modules and your code reader just asks for a simpler response.