speedometer issues

[patriotbluekj]

I have a 2002 liberty with 3.7L V6. The speedo goes haywire (bounces between 0mph and my actual vehicle speed.) when when I take my foot off the gas peddle. The crouse control doesn't work properly while the Speedo is acting up. I think it could be the speed sensor, or a loose electrical connection. But I'm not 100% sure. any thoughts?

 

[4x4kayak2112]

it could be the speed sensor, or a loose electrical connection.

I think your on the right track. First things I would check. Also has your KJ computer get wet recently?


Sent from my Home Phone using Tapatalk

 

[patriotbluekj]

I'm Not aware of it getting wet, is there a way to test it?

 

[tommudd]

Start by checking the connection back on the rear axle where it goes to the tone ring. Connection there gets dirty/ corrosion etc

 

[yellocoyote]

Also check the wiring that comes off the sensor for an nicks or places where the insulation has worn through from rubbing. That'll do it also.

 

[patriotbluekj]

i took apart my dashboard this morning and inspected the connections on the rear of the instrument panel, all connections looked good and were secure. crawled under the vehicle, located the speed sensor on top of the rear differential, the wiring harness is in good shape and has a solid connection to the sensor. the engine computers appeared to be in good shape and all connections appeared to be solid, but with out a way to test it I don't know. I assume that if it were the engine computers i would be having more issues than just a screwy speedo. now last night while running some errands, everything was working fine, didn't test cruise control, on my way home plugged in my OBD2 reader to get live data from the Vehicle Speed Sensor, and other than a slight delay of the needle on the speedo, the speedo, OBD2 reader, and a GPS speedometer app on my smart phone all read the same speed. at this point I'm stumped, I don't know what else to look at or to try and test.

 

[tommudd]

You may have moved the wires enough when checking them to make it work for a while

 

[tjkj2002]

I had messed up wires inside the connector at the speed sensor.The male connector coming from the body.Could not tell the wires were bad untill you removed the wires from the connector.


You can buy a new pigtail from the dealership if that is your issue.

 

[patriotbluekj]

You may have moved the wires enough when checking them to make it work for a while

It was working fine for a hole day before I inspected anything. At this point on not going to worry about it unless it starts acting up again

 

[patriotbluekj]

does any one have an auto pats store part # (AutoZone, ect.) for the speed sensor in the Diff. and is any one aware of any other speed sensor locations?

 

[tjkj2002]

does any one have an auto pats store part # (AutoZone, ect.) for the speed sensor in the Diff. and is any one aware of any other speed sensor locations?

Sorry no part # but all KJ's from '02-'05 run the speedo from the rear diff sensor regardless of ABS or not.For '06 and '07 KJ's it's run from the L/F wheel speed sensor(ABS sensor) if I remember correctly.

 

[Road_Runna]

im going through this problem myself. Autozone
The pigtail connector's part number is 948.
And the sensor itself is SU331.

My car was getting a bouncing MPH on the speedometer, and the other day it hesitated to engage into 1st and kept dying on me.

 

[GMDuramax]

02 KJ Sport Base. Lost Spedo. ? on Sensor

Hey everyone! So I have an 02 Sport Base 4x2 in Flame Red. Its been awesome since it has lasted 163K miles and I bought it with 30K on it a few years back.

Yesterday on my way home, going down my street, CEL comes on with P0205 and P0203 and then my Speedo quit working and pulled a code P0500.

Now the P0205 and P0203 I know are injectors, but then something strange. I cleared the code, then fired it back up... Now I get P0201... The code is bouncing around. Looking on the forums, is this indicative to a TPS sensor? The engine is running rough BTW.

As for the VSS... I have the Jeep lifted into the air right now in the garage. Looked at the connector in the back of the diff and all looks good. Took the sheeting off to inspect all the way up till it enters the floor and it looks good. Removed the connector and checked for power and and I am getting 10.5V which from what I have read on the forums is within spec. But when connecting everything back up and back probing the Speed Signal wire, I am getting a constant 1.6v. WHen I spin the rear wheels, it doesn't change.

Does that mean the sensor is shot? Since it is not fluctuating voltage? Any thoughts would be appreciated.

 

[GranpaQB]

It was working fine for a hole day before I inspected anything. At this point on not going to worry about it unless it starts acting up again

Be careful. I had the same trouble and one day the transmission wouldn't shift out of first gear. It was a long ride home. Like Tom pointed out my trouble was the corrosion on the axle which grounds the sensor. With the sensor off a little sandpaper on the axle did the trick.

 

[Billwill]

does any one have an auto pats store part # (AutoZone, ect.) for the speed sensor in the Diff. and is any one aware of any other speed sensor locations?

The 2002 KJ only gets its speed signal from the sensor on the diff.

If you have checked out all the wiring...including right inside the connector on the sensor....then you probably need a new sensor.

You can check that the speedometer works by holding in the odometer trip button while turning ON the ignition...this excercises all the panel light and swings the fuel, speedo, temp, tachometer etc. from side to side.

A loose connection on the diff sensor can take several runs to get working again once the problem is fixed...took about two weeks of driving on my 2002 CRD before speedo worked again!

 

[TheBlueKJ]

The 2002 KJ only gets its speed signal from the sensor on the diff.



If you have checked out all the wiring...including right inside the connector on the sensor....then you probably need a new sensor.



You can check that the speedometer works by holding in the odometer trip button while turning ON the ignition...this excercises all the panel light and swings the fuel, speedo, temp, tachometer etc. from side to side.



A loose connection on the diff sensor can take several runs to get working again once the problem is fixed...took about two weeks of driving on my 2002 CRD before speedo worked again!

Too bad they didnt make crds in 2002


Sent from my iPhone using the power of children's laughter

 

[CactusJacked]

Too bad they didnt make crds in 2002

..... for the U.S. market, but did for the international market.

 

[TheBlueKJ]

..... for the U.S. market, but did for the international market.

whoopsa daisy didnt think of that