1999 Ranger abs light, no Speedo. rough acceleration
#1
1999 Ranger abs light, no Speedo. rough acceleration
okay so all of my symptoms point towards a faulty abs speed sensor. At this point I have replaced the sensor, and the harness, with no results. I've had this problem before but it was easily fixed by replacing the sensor. this time doesn't seem to be the case. I was wondering if someone could point me in the direction of what to investigate next? Thank you much!
#2
RF Veteran
iTrader: (1)
Welcome to the forum
The VSS(ABS sensor on rear axle) wires run to the ABS Module, but they are Spliced and also go to the GEM(generic electronic module), Ford did this in 1998 to 2000 Rangers
GEM is used to convert the 20,000PPM signal to the 8,000PPM signal needed for speedo and computer, also cruise control
ABS is fine with 20,000PPM
So if ABS light is on and no speedo as well then problem will be the VSS or the wiring, also check for Code P0500, it means computer is not getting speed either
Now it could be GEM or ABS module is shorting out the VSS signal
Get a Volt/OHM meter
Pull off VSS connector
Test the wires going to the ABS/GEM with OHM meter
Test each wire to Ground/Truck Frame, only 1 should show Ground, low OHMs
Then test OHMs between the two wires, should be high OHMs if there is no short
If you think there is a short then disconnect ABS modules wiring connector and test again, if still shorted then GEM may be the issue
If wiring tests OK, then next you need to test if VSS is working, there are only two ways, well one way really
Jack up the rear axle
Hook up volt meter to the two connections in VSS, you can hit wrecking yard and get connector with some wire attached or if you still have your old harness...........
Set Volt meter to AC Volts, yes AC volts
Spin the rear wheels, direction doesn't matter
VSS sensor's output AC Volts, they generate their own voltage
With good fast wheel spins you should see .5-1.0volts AC
Yes, you can startup engine and run wheels up to higher speeds, just BE CAREFUL!!!
If you are not getting steady AC Volts then either the new VSS is faulty, yes it does happen, or the tone wheel inside the differential is bad, moved or is damaged
Make sure VSS you got is same length as old one, so goes in enough to read tone wheel
A Tone wheel looks like a gear, has teeth and gaps, each time a tooth passes by a VR(variable reluctance) sensor, it cause it to generate a voltage, faster the teeth go by the higher the voltage but voltage is just a by product, signal used is frequency, the AC sine wave
Picture here of tone wheel in rear axle: http://www.supermotors.net/getfile/7...ilt.jpg%20alt=
Smaller version is on crank pulley for crank sensor
And on front hubs if you have 4 wheel ABS, like these: https://turn5.scene7.com/is/image/Turn5/50706?$enlarged810x608$
The VSS(ABS sensor on rear axle) wires run to the ABS Module, but they are Spliced and also go to the GEM(generic electronic module), Ford did this in 1998 to 2000 Rangers
GEM is used to convert the 20,000PPM signal to the 8,000PPM signal needed for speedo and computer, also cruise control
ABS is fine with 20,000PPM
So if ABS light is on and no speedo as well then problem will be the VSS or the wiring, also check for Code P0500, it means computer is not getting speed either
Now it could be GEM or ABS module is shorting out the VSS signal
Get a Volt/OHM meter
Pull off VSS connector
Test the wires going to the ABS/GEM with OHM meter
Test each wire to Ground/Truck Frame, only 1 should show Ground, low OHMs
Then test OHMs between the two wires, should be high OHMs if there is no short
If you think there is a short then disconnect ABS modules wiring connector and test again, if still shorted then GEM may be the issue
If wiring tests OK, then next you need to test if VSS is working, there are only two ways, well one way really
Jack up the rear axle
Hook up volt meter to the two connections in VSS, you can hit wrecking yard and get connector with some wire attached or if you still have your old harness...........
Set Volt meter to AC Volts, yes AC volts
Spin the rear wheels, direction doesn't matter
VSS sensor's output AC Volts, they generate their own voltage
With good fast wheel spins you should see .5-1.0volts AC
Yes, you can startup engine and run wheels up to higher speeds, just BE CAREFUL!!!
If you are not getting steady AC Volts then either the new VSS is faulty, yes it does happen, or the tone wheel inside the differential is bad, moved or is damaged
Make sure VSS you got is same length as old one, so goes in enough to read tone wheel
A Tone wheel looks like a gear, has teeth and gaps, each time a tooth passes by a VR(variable reluctance) sensor, it cause it to generate a voltage, faster the teeth go by the higher the voltage but voltage is just a by product, signal used is frequency, the AC sine wave
Picture here of tone wheel in rear axle: http://www.supermotors.net/getfile/7...ilt.jpg%20alt=
Smaller version is on crank pulley for crank sensor
And on front hubs if you have 4 wheel ABS, like these: https://turn5.scene7.com/is/image/Turn5/50706?$enlarged810x608$
Last edited by RonD; 11-03-2017 at 08:56 PM.
#3
Old Guy User…
iTrader: (12)
Today I will be cutting my Grill Housing to fit with my new/moded Front Winch Bumper, (I mounted it closer to the body than it was meant to).
I need to cut two small notches where the bumper comes in contact, could have cut the bumper but it is Powder Coated now... too late !
Then to install the grill itself, a cheap aftermarket center section with Black, S/S, cross bars.
Next, to get some letters "FORD" something bigger but not lie a Raptor, similar to an Early Bronco Red Letters but larger, maybe I will print ou some templets with the EDGE Lettering. Not sure how the EDGE Lettering will look but it will keep with the theme of my Truck.
I need to cut two small notches where the bumper comes in contact, could have cut the bumper but it is Powder Coated now... too late !
Then to install the grill itself, a cheap aftermarket center section with Black, S/S, cross bars.
Next, to get some letters "FORD" something bigger but not lie a Raptor, similar to an Early Bronco Red Letters but larger, maybe I will print ou some templets with the EDGE Lettering. Not sure how the EDGE Lettering will look but it will keep with the theme of my Truck.
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gwillakers
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10-08-2012 12:13 PM