Hey my ABS and Brake lights are on and the speedo wont read over 35mph. So is it a bad wheel sensor or what?

 

Push the odometer reset button, turn the key on - don't start the engine - wait 15 seconds, release the button after CHEC appears, then write down all the 3-digit codes displayed.

Post'em here...................

 

Unfortunately his '98 has no self code reading abilities. '98 and '99 are the only years that must use a code reader.

 

You're right about the PCM and ECM, Bill, but the instrument cluster, being a self contained computer starting in '98, does have the self-diagnosis function built in, and will display the codes and run all diagnostics specific to itself.

Diagnostics routine runs after the odometer RESET button is released, stops after the DTC codes are displayed, and will resume when the RESET button is pressed again.

The diagnostic checks all the indicators, and will cause each gage to display ~1/4, 1/2, 3/4 scale, including the tach and speedometer.

For example, DTC 920, 921 and 999 would indicate no speed or mileage data from the PCM, and a general error - usually related to the speed sensor input from the rear axle.

You may have seen that specific in a recent post, also.

 

I went out and did that gauge cluster thing and no codes popped up anywhere.

 

I'll need to run down a '98 12v (left-overs from '97) to check it out - in the meantime, check your rear-wheel speed sensor, could be dirty connector at the sensor, or the one up by the engine\transmission harness.

Or a failed sensor - differential top center, on the slope to the pinion.

 

I had the same problem on my 04 gasser. Dealer said could be the sensor on the rear. But I found the fuse for my ABS blown. Just another idea to check.

 

The blown ABS fuse caused the speedo to read no higher than 35mph?

 

I checked the two fuses, they are both good. Guess I will try and clean the connectors and see if that helps.

 

Surely it's the sensor...

 

A faulty connection will give same symptom as a failed device - sensor, motor, etc.

Very often unplugging the connector and plugging it back in will solve the symptom - cleaning the contacts will resolve the failure

If that doesn't fix it, try the sensor - but it still could be the PCM.

 

https://www.dieseltruckresource.com/...d.php?t=116536

 

VORRA,

Your post describes a problem I'm having exactly. Today the brake/abs lights came on and the speedometer doesn't work until after 20mph. If the sensor is the problem, that's sounds cheap and easy enough to fix. I suppose you HAVE to change the fluid in the diff to fix it. I haven't checked where the sensor is but guessing it is below the fluid fill line. Do I just need to get the sensor and harness adapter? Also what is changing the clock position? Is that something I can do myself?

I guess the ABS won't work until I get this fixed.....? Thanks for the info.....great stuff here at DTR!

 

I have yet to change mine yet, been too busy to get to the dealer. The sensor is located on top of the diff housing and looking at my Haynes manual you just take a bolt out on the top and it will slide out.

When he said changing the clock position that means that dodge has changed what angle the plug comes out of sensor. EG: say you looked at the sensor and pictured a clock, the original plug came out at say 3 o clock well the new comes out at a different hour.

As long as the ABS light is on that means there is a fault in the ABS system and it will not work at all.

 

Exactly what spitfire said, it's a no brainer. Pickup the sensor, and it's a very straight forward fix. Let us know how it goes.

Great site we have here.