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Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 8556
Experience:  I am ASE Master Truck Certified.
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I m having problem with speedo meter on freightliner

Customer Question

Hello
I m having problem with speedo meter on freightliner Columbia 2007 with cat c15 , gauge move up/down when driving on 65
Submitted: 6 months ago.
Category: Medium and Heavy Trucks
Expert:  Jeremy replied 6 months ago.

My name is ***** ***** I will assist you with your question today.

I'm an independent contractor and I don't get paid until a rating has been made.

We can go back and forth as needed to help resolve the issue you are having. Follow ups are free after ratings, so rate in confidence!

When you state it moved up and down, you mean it bounced? Does it do it at only certain speeds or at all speeds?

The most common on this issue is a bad VSS. It is mounted on the transmission just before the output shaft. It detects your road speed. When it messes up, it will make the speedometer bounce or drop out completely. Change it out first since they are very difficult to test and are pretty cheap. Then see if the issue resolves itself.

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Jeremy

Customer: replied 6 months ago.
Driver complain that while driving at 65mph gauge jump up down come down to 35 and move back to 65We already change the VSS and trace the wire to ECM
Expert:  Jeremy replied 6 months ago.

Was the pinion nut torque checked to make sure it didn't come loose? Frop the shaft and high torque it wit ha 3/4" impact just in case there is a slight looseness causing vibration and inaccurate reading on the VSS.

If all is good, then there is a cluster fault with the speedometer if the wires ohm tested good to the ECM. it won't be the connection in between for it will throw a J1939 code for communication. You didn't mention that so that leaves only those 2.

Customer: replied 6 months ago.
I already check the transmission nut and for loose
It's tight
Expert:  Jeremy replied 6 months ago.

That can only leave the cluster itself then. The cluster is dropping out internally on the board for the speedometer.

Customer: replied 6 months ago.
Already tried the swapping the cluster with other truck
Customer: replied 6 months ago.
There was code in logged 231-12
Expert:  Jeremy replied 6 months ago.

hat is the engine retarder and has nothing to do with the cluster.

What all have you done already?

If you have a new VSS, tested the wires, tried another cluster, that is all the electronics on the truck. Something was missed or something didn't get tested. It can be mechanical where you would have to go in the transmission and replace the tone wheel, but I seriously doubt that is the case because you are getting a reading. So you have a wiring issue, a module issue which will need a programming attempts to clarify, a collision issue (again programming takes care of that) or something was missed in the checks of this.

Customer: replied 6 months ago.
Do 231-12 j1939 code was logged due to this
Customer: replied 6 months ago.
Or j1939 can cause this problem
Expert:  Jeremy replied 6 months ago.

The J1939 can have collisions occur from a bad terminating resistor, but you only have 1 code. That code is for the engine retarder to the ECM. It isn;t a code for the link between the ECM and the ICU or the ECM to the SAM. It is a CPC only code which is for the engine.

You could have "noise" on the network from a bad sensor which can cause the speedometer to drop out since it relied heavily on the J1939 network.

Customer: replied 6 months ago.
what should I check now
Expert:  Jeremy replied 6 months ago.

Wait a second...

That is the retarder code on the trans. Duh... Brain fart. Just woke up. Getting old...

There is a J1939 fault between the ECM and the TCM. Do you have CAT software to where you can run a calibration test on the two and see if the code will clear? If not, Catman our Cat expert might know how to get this to test out better. I don't have the pin test check for CAT.

This is what comes up for Detroit, but CAT is requiring me to access CAT servers and I don;t have that active because I'm a Detroit tech in the shop, not a CAT tech.

"If code 84/12 displays, the fault is with the programming of the ECM, or a short exists to the J1939 data link. Contact OEM for VSS (Vehicle Speed Sensor) troubleshooting."

This is for the one for the Detroit. CLICK HERE

Why you look at that, I'll open this for Catman to get on and help you with the CAT engine pin out. He is a CAT trainer so he really know his stuff on that engine.

Customer: replied 6 months ago.
K thanks ***** have et
Expert:  Cat Man replied 6 months ago.

Thanks for asking your question. I will try and help you out.

Is 231-12 the only code you have? Or do you have a Vehicle Speed code?

Since you have ET, can you tell me under the configuration screen how the vehicle speed input is programmed? It can be programmed to pins 32 and 33 or J1939.

Customer: replied 6 months ago.
Truck is not here but speed sensor wire plugged in
Customer: replied 6 months ago.
Pin 32 and 33
Expert:  Cat Man replied 6 months ago.
Thanks for the information
This indicates the vss is wired straight to the ECM.
Since you have already replaced the VSS. I would suspect there is a problem in the harness that connects the vss to the ECM. I would try replacing the harness next. It's possible the people is the ECM but that's extremely rare.
Please reply back if you need more help or have more questions. I am happy to assist.
Customer: replied 6 months ago.
We already run the new wires and tried swapping ECM
Expert:  Cat Man replied 6 months ago.
Thanks for the information.
Are there any codes for loss of vehicle speed in the ECM?
Customer: replied 6 months ago.
Expert:  Cat Man replied 6 months ago.
What's the code number?
Customer: replied 6 months ago.
I don't remember the code #
Expert:  Cat Man replied 6 months ago.
I see. Thanks for the information.
If you have a vss code. There are only 4 things that can cause it
A faulty vss
Faulty wiring to the vss
A faulty ECM
Or a problem with the chopper wheel in the trans the vss reads.
Customer: replied 6 months ago.
Waiting for truck to come back ll let you know thanks
Expert:  Cat Man replied 6 months ago.
10-4.
Expert:  Cat Man replied 6 months ago.
Hey. I just wanted to see how things were going. Please let me know if you need more help. I am happy to assist. If my information was helpful, please leave a good or higher rating so that I receive credit. Thanks.
Customer: replied 6 months ago.
Hello truck is here today
Customer: replied 6 months ago.
Code 84-10 logged
Expert:  Cat Man replied 6 months ago.
Thanks for the information.
If the ECM, the wires, and the sensor have been replaced. I must assume there is a problem in the transmission at the chopper wheel the sensor reads.
Please reply back if you need more help or have more questions. I am happy to assist.
Customer: replied 6 months ago.
Chopper looks fine and tight
Expert:  Cat Man replied 6 months ago.
If the chopper is tight. Then you must have a problem in the harness, sensor, or ECM. These are all the items that can cause this code.
Customer: replied 6 months ago.
K let me check wires again
Customer: replied 6 months ago.
I already change the sensor twice
Expert:  Cat Man replied 6 months ago.
10-4.
Customer: replied 6 months ago.
Expert:  Cat Man replied 6 months ago.
The only things that can cause an 84-10 is a bad sensor, faulty wiring harness, faulty ECM, faulty chopper wheel.
I can only assume one of the new parts you installed is bad.
Customer: replied 6 months ago.
Do the sensor wire need to be twisted all the way to ECM
Expert:  Cat Man replied 6 months ago.
It helps fight outside interference. I would twist them and cover the wires with some type of loom.

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