Wheel Speed Sensor Help

huntr1

huntr1

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1998 Pontiac Grand Am 2.4L Auto

My ABS and ETS (traction control) lights come on and then will not go off until the car has warmed up completely and been driven for atleast 5 minutes with the lights on. I have to shut off the car for them to go out. When the lights come on, I feel a load of resistance added to the front left wheel (kind of like the car hits a sticky patch). Had the front left speed sensor replaced by the shop I use, but it was almost $200.00, and the problem is still there. The computer is now pointing at the REAR left wheel speed sensor and saying it's bad. Anybody know how to replace these sensors? If it's not too difficult, I can do it myself and save a big load of $$.
TIA
 
Bustem' Down

Bustem' Down

Give Peas a Chance
huntr1 said:
1998 Pontiac Grand Am 2.4L Auto

My ABS and ETS (traction control) lights come on and then will not go off until the car has warmed up completely and been driven for atleast 5 minutes with the lights on. I have to shut off the car for them to go out. When the lights come on, I feel a load of resistance added to the front left wheel (kind of like the car hits a sticky patch). Had the front left speed sensor replaced by the shop I use, but it was almost $200.00, and the problem is still there. The computer is now pointing at the REAR left wheel speed sensor and saying it's bad. Anybody know how to replace these sensors? If it's not too difficult, I can do it myself and save a big load of $$.
TIA
Click to expand...
That sounds weird. Did your shop say the rest of the electrical is ok? I'd hate to see you change out all the sensors when it's really an electrical problem of some sort. I myself am not too good with electrical because these cars get more and more complicated each year.
 
huntr1

huntr1

.
I have taken the car back in to be checked and re-checked since the first sensor was replaced, and the lights kept coming on. This last time I took it in, I watched while they scanned for codes. The front left sensor came up again (the one I had replaced) and the rear left one also. The first time I took it in after having the sensor replaced, all they did was lubricate the switch on the gear shift that turns the ets on and off (I never turn it off, so the switch never gets used, so it shouldn't have an impact) it made no difference. I am thinking of taking it to the Precision Tune (I think that's it) in the Park and see what they say. My buddy has gotten good work from them recently.
 
dustin

dustin

UAIOE
Try disconnecting the negative terminal on the battery and letting it sit disconnected for a few minutes. Then reconnect and see if the problem is still there when you intially start up the car.

Autozone can check your codes for you for free.

I'm not sure how the traction control works on your vehicle, but being that the front left wheel is being slowed down to keep from "slipping" by that brake, the computer might cause that brake to be applied because the left rear traction control sensor thinks its wheel it's wheel is slipping (while it really isnt), thereby applying increased brake pressure to the front left wheel because the computer thinks that tire has more traction.

This is just a guess mind you on how it might work.

I don't know how hard those sensors are to swap out but IF they are interchangeable from front to back you could try swapping the front left with the rear left or the rear left with the rear right and see if the "stickiness" occurs at a different wheel. Or hit up a local junkyard...

just some ideas...good luck :yay:
 
huntr1

huntr1

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Didn't know about Autozone! That coulda saved me some serious $$ over the last 2 years. The shop I use charges $50 or so just to scan the codes.
 
huntr1

huntr1

.
OK, it is definately temperature related. Yesterday morning it was cold when I left home, and about 3 miles into my drive, the lights came on. Drove for about 10 miles and then did the "turn it off, turn it back on" deal and the lights went off. They were on again yesterday afternoon when I left work, drove about 5 miles (15 minutes) did it again and they went off. This morning it was relatively warm when I left home (6:30) and the lights never came on.
 
willie

willie

Well-Known Member
Some codes (like the ABS) can't be read by the less expensive code readers. You may save yourself some time and money and have a GM dealer analyze it. That seems like a rip off but it's life in today's car world.
 
Oz

Oz

You're all F'in Mad...
Sounds like you have a kinked, misrouted or broken wire, leading to one of the speed sensors. However, the first thing I would do is clean and check all of the grounds on that car. Chances are good that your mechanic turned your check engine light off, replaced the hub assembly, plugged the wires back in, and tested NOTHING. Codes and code readers don't really mean crap if you don't test and troubleshoot the problem.

The test procedure for your wheel speed sensor will be something like:
Disconnect the connector that connects the hub sensor to the vehicle wiring harness. Turn the switch on the meter to resistance/OHMS position. Make sure that your meter leads are in the COMMON (-) position and Volts Ohms (+) position
Normally the only other lead position on the meter would be AMPS. You do not want the lead in that one!

Turn the switch to the lowest resistance setting. Short the tips of the meter leads together. If the leads are in the correct position and your meter is working, the display will read 0.000 ohms (it may read a few 1/10 of an ohm or less depending on how good the meter is and how good the lead connections are.)

You need to read the HUB side of the wiring harness. There will be two pins in the connector. Examine them. Make sure they are clean, dry, free of corossion (use a flashlight and magnifing glass) and make sure the pins are straight. Examine the other side of the plug also.

Read the resistance of the sensor by putting the lead tips on each pin or connector depending if the hub side of the wiring harness is MALE OR FEMALE.
You should read: 850 to 1350 ohms. (Consult the service manual for your specific vehicle on the exact range for your Grand Am.)

Wiggle or have someone wiggle the wiring to the hub as you read the resistance of the sensor. Make sure that the reading does NOT vary as you are taking the readings of the sensor.

If you read within that range and the value does not vary when you move the wires, the hub and sensor is probably good.

Switch the meter to DC Volts. You will be looking for voltage on the wiring harness side of the connector. Select a scale that will read at least 12 Volts DC. You will be looking for a voltage above 1 volt DC. Turn on the ignition but do NOT start the engine Read terminal "A" of the vehicle wiring harness side of the plug to chassis ground. You should something above 1 volt DC, Read terminal "B" to ground. You should see a voltage above 1 volt DC.

Good luck with it!
 
Elle

Elle

Happy Camper!
huntr1 said:
Didn't know about Autozone! That coulda saved me some serious $$ over the last 2 years. The shop I use charges $50 or so just to scan the codes.
Click to expand...
Hubby has a computer at home as well if you ever need it checked again.
 
kwillia

kwillia

n/a
huntr1 said:
Can you have him read this thread and see what his thoughts are on it?
Click to expand...
Gee, huntr, I'm thinking he wouldn't need to have his own car 'puter if he was good enough to figure out what's wrong with these new fangled vehicles based on a layman's description of the problem...:confused:
 
huntr1

huntr1

.
kwillia said:
Gee, huntr, I'm thinking he wouldn't need to have his own car 'puter if he was good enough to figure out what's wrong with these new fangled vehicles based on a layman's description of the problem...:confused:
Click to expand...
Gee Kwillia, I thought that maybe he had a computer at home because he's a mechanic by trade and has the computer so he can work on his cars at home. I may be wrong about his profession, but that is what I thought.

My whole issue is that based on what I have read on the ABS system in my car, it should NOT be possible to get trouble codes based on anything other than bad electrical connections/wires/sensors. However, based on what I have experienced with my car, it seems to be some physical problem since it seems to be influenced by temperature.
 
huntr1

huntr1

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Weird as it sounds (and to me it is weird), both sensors went bad. Had them both replaced. Now I am dealing with a transmission code. PO751. One of the shift solenoids/switches inside the transmission is stuck. Ain't I lucky? More money out my pocket.
 
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