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Speedometer Jitter affecting transmission
Posted: Thu May 23, 2013 4:21 am
by marco10
About a few months ago, the ABS light and the hand brake light came on. A few days ago the speedometer started to jitter back and forth while driving. The transmission feels like it gears down once in a while. Can someone please explain this? I'm wondering if the ABS sensor is affecting the speed sensor. Are these 2 sensors on the same board? Is there something wrong with the transmission? I have no idea. Please help. Thanks.
Re: Speedometer Jitter affecting transmission
Posted: Thu May 23, 2013 1:39 pm
by Drummernaut
You may want to get a scan tool on it too check the DTC code. The ABS uses the wheel speed sensor so it would be the wheel speed sensor affecting the ABS. For example, A DTC code of C0221(RF Wheel Speed Sensor Circuit Open) will cause both the ABS and Brake indicator lamp to go on for my 1999.
The wheel speed sensors go to the Electronic Brake Control Module. You can always just look at the speed sensor connected on the rear of the wheel hubs, there is only one wire to follow so it should be easy to find but it helps to know which one is bad or if that is the problem at all. That is were the scan tool helps. The sensors are easy to replace.
Should be able to scan it free at your local auto parts store.
As far as the the speedo jittering, I am not sure. My understanding was the speedo got its info from the one of the speed sensors on the transfer case but you have a RWD so I would assume the tail cone of the transmission. Some one else may know this info or I can check my book later.
It is possible your transmission may be going in and out of TC lock/overdrive and that is what you are feeling, especially going up slight inclines on the freeway. This would be normal to a certain extent.
Good luck, I am sure others will chime in.
Re: Speedometer Jitter affecting transmission
Posted: Fri May 31, 2013 9:38 am
by marco10
Can anyone help me in locating the VSS (vehicle speed sensor) on my vehicle? Or if it even has one? Would like to replace if needed after I check all connections and wires.
Re: Speedometer Jitter affecting transmission
Posted: Fri May 31, 2013 11:05 am
by Drummernaut
Since you have a RWD it should be on the passenger side of the transmission tail cone. You should see a wire going to it.
Re: Speedometer Jitter affecting transmission
Posted: Mon Jun 03, 2013 3:51 am
by marco10
I replaced the VSS. The speedo now works properly and the van is running smoothly. No more gear shifts. Now, to take care of the ABS light.