so I have 1999 Ranger 3.0 2x4. a couple weeks ago it started acting up and would at start up have the ABS light on, and the OD light blinking, with those the Speedometer would no work and neither would the odometer. The other gauges worked just fine(There is no Tach) . The OBD code was for the ABS Speed Sensor on the Differential. I replaced that and with that I noticed the wire clip was damaged so I replaced it as well. I resealed the wires and put it all back together and the problem is still occurring. It doesn't light up my cluster on startup but once I get an interstate and hit 60-70 mph the Speedometer will start going crazy and bouncing from 0-70 and then it will stop at 0 and the transmission seems to drop into neutral. Once the vehicle speed drops to around 30-35 the transmission will re-engage and it will be fine until I get it to 60+ again. I don't know what else to look at since there are no codes being put up for me to point at. From the looks of the ABS Speed sensor it seems to be a magnetic reader of some sorts which makes me think there may be a tone ring or something similar it reads in the Diff. I don't know much about vehicles but I know about tone rings from an Escape my wife and I had that had a broken one on the front drivers half axle.

How Should I approach this and what steps would you all suggest to attempt to remedy the problem? for reference it is a 1999 Ford Ranger 2x4 with the 3.0 v6. it has 170,000 miles currently

 

Welcome to the forum

From 1998 to 2000 Ford used the rear ABS sensor for ABS and its signal was sent to the GEM Module, behind the radio, to be recalibrated for speedo/odo, computer and cruise control

Yes the ABS sensor is called a variable reluctance(VR) sensor and does use a tone ring
VR sensors generate their own voltage, an AC voltage signal, a sine wave, that varies with speed of tone ring passing by it
The frequency of the signal is what is used not the voltage, and only 1/2 of the signal is used
AC voltage sine wave goes above and below 0 volts, one of the wires at the sensor is grounded, so only the + 1/2 of the frequencies are used

Rear ABS sensor generates about 20,000PPM(pulses per mile)
All electronic Ford speedometers are calibrated for 8,000PPM
So Ford uses the GEM(generic electronic module) to change the 20,000PPM to 8,000PPM and then send that out to speedo, computer and cruise

If you have 4-wheel ABS its a little different, the 4WABS module does the conversion

Is the ABS light off now, after the new sensor was installed?

If not then you have a wiring issue
Tone ring issue is a long shot, not 0 shot, but long shot, picture of rear axle tone ring here: https://i.ytimg.com/vi/l7xin5Uyjd0/maxresdefault.jpg
It is press fit behind the ring gear so it could slide off center I suppose, and only give partial reading
But I would expect that to cause an irregular reading all the time, not above a certain speed

The sensors two wires run to the ABS module, and there will be a splice where the signal is tapped and runs to GEM behind radio

If wires at the sensor are pink and grey then Pink wire is usually the Grounded one
You can test that with OHM meter, its grounded in the ABS module usually, but can be spliced to Ground, Ford was all over the map on this wiring from 1998 to 2000


And as another long shot, it could be the ABS module or GEM is causing the issue on the 2 sensor wires, if either is shorting out a wire FROM the sensor during operation then both would be effected
Extreme long shot but not a no shot
A damaged wire is 99% more likely

 

the ABS light is off currently. I may have done the wiring wrong but I was very methodical in how I did it, mistakes are possible though I will check them again. How would I know if I have 4wheel ABS or not? I have front Discs and Rear Drums. Thanks for the picture of the tone ring, from looking at that I know straight off that is beyond my skill to repair if that is the problem.

I will recheck the wires, is it possible to pull them off completely from the ABS Sensor to where ever they connect from there so I can replace the whole length if I need to rather than just patch in a repair which would potentially lead to more issues? I can't say for sure what colors the wires were, they looked grey to me, one had a black line and had a white. They may have been grey and pink but being red/green color blind I can't see pink very well. I did match the black line up though. Also if the GEM Module needs replaced is that something that comes pre programmed or do I have to take it to a dealer for that?

 

There will be a wiring harness(2 wires) at each front wheel ABS sensor reading its Tone ring
And you will have this: https://www.ranger-forums.com/attach...10226-1819.jpg
In the drivers side of engine bay by the power brake booster and master cylinder

If ABS light is off now then new VSS(ABS sensor) solved that problem so it is working.

Use an OHM meter to test the old sensor, 190–250 ohms is expected from a good sensor, testing the old one will tell you if it was bad or new one didn't fix anything

If the wiring at the rear sensor was questionable then take the old one to wrecking yard and find new connector that fits and cut its wires so you can splice them in to your harness
Most RWD or 4WD Fords will use the same ABS sensor on rear axle so same connector