Speedometer and cruise control not working properly

HATTONJ48

MEMBER
1999 DODGE DAKOTA
5.2L
V8
4WD
AUTOMATIC
120,000 MILES

The speedometer was working erratically, now doesn't work at all. The cruise control light comes on but can't set. Truck shifts fine and runs fine. Check engine light is on. Do I need to replace sensor or transmission or rear end? I don't like to throw parts at it. I'm leaning towards the rear end because it shifts fine.
Thanks for any help.

1 Reply

CARADIODOC

MECHANIC
33,738 POSTS

The first step is to read and record the diagnostic fault codes. Use a code reader if you have one, but if you don't, Chrysler made doing this yourself much easier than any other manufacturer. Cycle the ignition switch from "off" to "run" three times within five seconds without cranking the engine, leave it in "run", then watch the code numbers appear in the odometer readout.

You can go here:

https://www.2carpros.com/trouble_codes/obd2

to read the definitions, or I can interpret them for you.

If you have a speed sensor on the rear differential housing, that is for anti-lock brakes, not for the speedometer. The speed sensor for that and the cruise control is on the driver's side rear of the transmission.

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