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Ball joint, shaking, and speedometer


I have a Nissan Maxima 2001. As my username suggests, I have had huge number of repairs in the past 10 years Ive had it.

My specific issue now is, a local mechanic told me that my right wheel was loose and the ball joint had to be replaced. Also my car was shaking while idling at a traffic light when the engine was on. (the shaking increased when I am on drive mode compared to neutral).

He said he will replace the spark plugs and ball joint to fix both issues.

After ~ 350 bucks, the car was still shaking and guess what…the speedometer and odometer both stopped working just as I drove out of the repair shop !

Is there a chance they accidentally pulled some wire while replacing the ball joint or the spark plugs? Is there a connection between either of these parts and the wires for the speedeometer/odometer?

Now all this was about a month ago.

(btw my check engine light has been on forever and the ABS light has been on for a few months.)

The latest situation is: The shaking has somehow completely stopped (it used to be sporadic anyway but now it seems to have completely stopped.)

The speedometer and odometer are still not working.

Also last week the fuel gauge stopped working!!

Please if you can help that would be appreciated. Otherwise I am at the mercy of the evil mechanics.
Thank you.

Ok you post about one thing and reveal another. Try this. Go get the engine codes read for free at one of many national parts distributors and post the result here. We can help but you have serious and multiple possible issues with out enough detail. You have a shaking engine with a code light. That is where to start. your “mechanic” must have told you something about why the light does not go out even though you pay him to fix the car?

Follow @euryale1 advice get the codes and post them, this will give us somewhere to start. Auto Zone will check the codes free. If there’s not an Auto Zone nearby call some of the other parts stores and ask if they do free code readings. Speedometer and odometer not working sounds like a bad VSS or something in the VSS circuit (vehicle speed sensor). If it is the VSS it will store a code in the car’s computer. Anytime the CEL is on have the codes pulled from the ECU to find out where the problem lies before throwing parts at an unknown problem this will get the car repaired correctly with minimal parts.

Thank you Fordman and euryale1. I’ll have the codes checked.

There is nothing about replacing ball joints and spark plugs that would affect the speedo and the other gauges. My gauges acted crazy and the reason was my battery was low on charge and the diagnosis is a bum alternator.

Since you’ve been driving a month or so like this, I think you gauge “cluster” has gone bad and needs to be replaced. If you hate this car so much, why have you kept it for 10+ years? It might be time to sell it or donate it and move on.

So, I just took it back to the same mechanic and he read the code for free.

It comes out to be "P0440 EVAP Control System " and there were no other errors.

Any thoughts?

Also just noted that my engine temperature meter is also not working, besides the fuel meter, speedo and odometers. (The speedometer does show a reading but its about half the actual speed and odometer counts also about half the mileage traveled)

The mechanic is suggesting that there is a bad connection behind the dash, and that he will open the dashboard to check it out. I am a little afraid if he is knowledgeable enough to connect everything back !!

Thank you again for your help.

The PO440 code could be from a gas cap that isn’t sealing properly or a vacuum leak in the EVAP system. Checking for vacuum leaks is where I’d start, if none are found you could try a new gas cap to see if that resolves the problem it may or may not, but a new gas cap should only cost a few dollars. Here’s a link to other possible causes The speedometer only registering half speed/mileage I have no ideas about unless it’s the VSS going out.

Regarding the speedo problem only:

Out of curiosity, does your cruise control operate normally?
In other words, does it allow itself to be set when you go - say - 50 mph?
The minimum speed for cruise control to work usually is around 40. It will not let itself be activated when you go slower because that’s dangerous. That could buy you a clue:

According to the schematic I have, the cruise control module (“ASCD control unit”) is an entirely separate module and takes the same signal as the dash (“Unified Meter Control Unit”). That signal comes from the TCM (“Transmission Control Module”).

What I’m thinking is that if it lets you set the cruise control at 50, it clearly sees 50 - not half of 50 because it wouldn’t arm itself at 25.
If it doesn’t arm itself at 50, the signal going to both those modules is clearly bad and pulling the dash apart is an exercise in futility. If it does arm itself, there’s probably something wrong with that “Unified Meter Control Unit” in the dash.
That common signal that feeds both the cruise control and dash is labeled VSP-2 and it comes from the transmission control module. That signal likely finds its way from a wheel speed sensor that the transmission computer somehow makes into a signal your dash and cruise control modules understand.

Regardless, yanking the engine control module will not help you.

Edit: just noticed the ABS light. That kinda points in the direction of a wheel speed sensor as well… Maybe not directly but it definitely is in that direction.

RemcoW, brilliant idea…although I’ve never really checked at what speed it activates. I’ll do this on the drive back home tonight.

I do notice that the transmission switches at the right engine RPM (at least that is working well for now !). In fact that is how Ive been estimating my speed. I know that when the RPM is stable (doesn’t fluctuate much with gas pedal) it is about 1500rpm for 45 mph and reaches 2000rpm for 60 mph. Not sure if that is an added clue, but i will test out the cruise control today.

Thanks again !

And Fordman thanks for the links.

I guess it is worth checking the connection for the dash cluster, but it means removing the cluster to get access to the connection. We had a “spammer” recently from a company the fixes and resells dash clusters. These things are now sealed units with circuit boards and “chips”. They aren’t fixed by normal shops, they need to be sent out to specialist for repair.

So, I did check the cruise control. It definitely does not arm at slow speeds …but does arm just about 40-50mph. ( this is my estimate of the speed from the gear and RPM but must be pretty close)

So RamcoW, your reasoning would tell us that it is the “Unified Meter Control Unit” in the dash …I guess I should rather take it to the Nissan service center rather than the local mechanic?

Thanks this was a great idea. If you are this good at diagnosing without even seeing the car …hmmm. Hope you are rich :slight_smile:

Another way would be that a mechanic plug a monitor in to see what the system thinks it is doing. Lots of readers, besides being able to read the codes when the check engine light comes on, can also read real time parameters like speed. I’m surprised the mechanic didn’t do that, actually.

Yes, it does seem to be the dash that’s at fault.
You may want to get that checked by the dealer because a local guy may just toss parts at it to see what fixes it.

Rich?? HAHA - No, Just like fixing things and helping out where I can, like the other guys here. Between all of us, someone is bound to hit the nail on the head.

Yeah, a friend actually suggested that I rent a code reader and check out the speed.

But I’ll take it to the Nissan dealer and I get my wallet emptied…(.they usually like to change entire units and dont care about saving money for the customer…as the local guy will.)

Your time on this is much appreciated.

Actually I think you have a sensor issue, but only if you want to do it your self. The cruise will not arm in most cars below forty. But that means your gauges read incorrect as you noted before. There may be a dash only rpm/speed sensor on the tranny. I had to replace both in my mitsu/chrysler. These are usually in odd places but look it up for your car on the web.