SVS/ABS Lights - Brakes Appear Fine

[eaglesrealm]

Originally Posted by windwin

I got a same problems on my Grand AM GT 1999.
Anybody can share more details for DIY.
SVS/ABS/TRAC off lights are on.
so, dear eaglesrealm, would you give me suggestion for repair myself?
Thanks a lot

Windwin - I'm trying to remember what related thread I posted a description in.
The fix itself is fundamentally easy. The hardest part can be pulling off the whell hub assy. Just a pain in the a$$ sometimes to get off. They do make pullers, not sure where you can rent/borrow one from.

The other thing you need to know is which wheel has the bad bearing assy.

Basically, as best I can remember that setup from memory

1) Break free axle nut (AutoZone will lend you an axle nut socket)
2) Remove the wheel
3) Remove the caliper
4) Remove the Rotor
5) Remove the axle nut
6) Unhook the hub assembly speed sensor
7) Remove the hub assembly
8) Install the new hub assembly and rehook up the speed sensor
9) Hand tighten the axle hut
10) Replace rotor, caliper and wheel.
11) Lower car, finished torque on axle nut and wheel lugs.

Thats just what I remember, I make no claims to it's validity LOL

[amerpwr]

my cv joint went out about a year ago and took it to get fixed..well when i picked it up from the shop my abs light was on so i changed my brakes and made sure both abs plugs on the calipers were plugged in but the light stayed on..so when i swapped my engine out i noticed when the shop took my cv joint out the cut the wires to the plug and never reconnected them

[GrandFraggle]

I haven't taken a close look at grand am sensors recently but on other type vehicles the ABS sensor is a magnet that detects wheel rotation speed. Usually right next to the bearing. For grand ams it may not be possible but on other types a shot of compressed air to to blow off the metal flecks from the magnet has cures ABS light.

[wildblue]

I've having the same problem with SVS, ABS, and Trac Off lights coming on on my '02 Grand Am GT. I hope it's not the hub assm. again (I've replaced left and right in the past year, and there's not that tell-tale noise) I reseated the LF and RF speed sensor and hit them both with some compressed air, but the lights are still coming on. They usually don't come on until I've driven for a short time - sometimes 2 minutes, sometimes 10. Any other tricks? It's cold here (I've heard that triggering it) or maybe it's just the abundance of road salt I've been over in the past week. Any other ideas? I borrowed the code reader from the auto parts store, but it said 'no faults found' ?

EDIT: Ok, sometimes the lights are one when I start the car, othertimes it takes a few minutes to kick on. Those minutes could even just be in the time it takes the car to warm up in the garage. Is there a way to at least find out which sensor is tripping it?

[tvtech]

I had the same problem with my 01 GT. Before spending all the money on hub assemblies, disconnect the sensor assembly plug, spray it with contact cleaner and reconnect. That will most likely solve your problem.

[Jgoad2]

so i took my car in becuase i was having the same problem abs/svs/trac off. anyways he is a well known mechanic that we have been going to for years and he said it could be the alternator? i have a sub and an alpine amp. but anyways he just called me and said it was the battery that was goin? does anyone else have this problem or heard of it??

[eaglesrealm]

Originally Posted by Caputo777

I want to try this - I've seen several ppl suggest this on this thread but unfortunately I have no clue what to look for. Does someone have a detailed description or a picture of this so i know where to find the sensor assembly plug?

I do not have a picture, but it's not hard to find.

Take off your wheel.
I find it easier to also remove the caliper and rotor, especially the first time you are trying to fumble to see the exact location/connection features of the clip.
Either way, there is a black shield behind your wheel hub assembly. On the shield is the sensor connector you are looking for. You can disconnect the connectors from eachother without removing that assembly from the shield. It just has a release tab that you pull back and pull the connector down towards the ground.

I just had the harness replaced going to 1 of my wheel hubs . You might want to check them . Idiot lights were only coming on when it was wet out.

[Ram_Air_Brad]

I had the same problem on a 2001 Grand AM SE, my GM dealer said some of the GA's had a sensor on the drivers side behind the wheel (speed sensor i'm guessing) that might not have been factory sealed and the light comes on when moisture gets in the wirring connector. My dealer dried out the connections with a heat gun and then resealed the connection. I haven't had a problem since.

[AznGA]

How critical is this problem? I have these lights come on randomly once in a while and they dissappear when I shut the car off. No wierd noises from the wheels either. I am planning on living with it.

[eaglesrealm]

Originally Posted by MBLAX32

Alright, so I've read this thread multiple times and searched for hours on trying to get my SVS/Trac/ABS lights to go away. Originally I go to Midas(dumb idea) and they tell me "yeah you've got a lot of play in these front two hubs, better replace them". Well, so reading this thread led me to believe hey, yeah that'd make sense. Ok, turns out the actual problem isn't even in the front, nor are my hubs themselves bad. It's the left rear speed/abs sensor. I still need to replace the entire hub though I would assume? Any input would be appreciated-

Sorry that Midas may have led you astray. If you had significant play in your hubs, they still may have needed replacing even though they were not hurting the ABS. The best way to know which to replace is to get the code read, when it's active. Since ABS codes cannot be read with a the basic OBDII readers, you have to go somewhere other than Autozone and have it read. There are some small Mom and Pop's here that will do it really cheap. (Especially if they think you will let them do the work)

A code read should have told you which wheel that was having an issue, and you should have replaced that hub assy. Good luck!!

[eaglesrealm]

Originally Posted by AznGA

How critical is this problem? I have these lights come on randomly once in a while and they dissappear when I shut the car off. No wierd noises from the wheels either. I am planning on living with it.

If the lights are off, and you need to make a panic stop, your ABS SHOULD still work adequately. I cannot prove that to be the case 100% of the times, but when mine was "randomly" coming on and off, my ABS would still go through the motions of slip control. Even with all the said, I would anticipate the worst case, in which you would still have base brakes, but your ABS will not function correctly or at all.

How critical?!? It's up to you to quantify. I personally want a car with ABS all the time, which is why I replaced both wheel hubs when they started failing. ABS is something I know to be useful and worthwhile, so I make that choice to keep it in working order.

[danielcastro]

i had same problem with a front speed sensor, i was gonna change the hub, but i found that the problem was just the connector and it wasnt conducting the signal. i hope this helps you. i tried adding some piece of cable on each hole.

[ford_man1984]

this has happened to me aswell b4 spending any money on it check the tire pressure on both front tires make sure they are the same, thats all my problem the right tire was going 5 kph faster then the left which triggered the speed sensor . amazing what 6 pounds of air can do

[MBLAX32]

Alright, so how about this one..
Finally got a new hub to replace my rear driver's side one which had gone bad, in turn I was also experiencing the famous "SVS/ABS/Trac" light show display in my dash. So they put the new hub on today, checked the old one and sure enough the sensor had gone bad.. after installing the new one the 3 light parade was still on.. hmm.. strange..

After checking the readout on the new hub it was fine nothing shorted or anything, and a signal from the ABS controller was going out just with no return signal. Turns out there's now a short in the wiring which goes from the rear hub up into the car underneath the back seat, along the door sills, down through the firewall and up underneath the battery where the ABS box is located...

Anyone else have this type of ridiculous crap happen? I love the GA but damn I can't wait to get rid of this one..

[gectek]

I had a similar problem with both my rear sensors. so here is what i thought. both sensors really cant go out at the same time. I had a scan tool at my school, so i used it through the month. same codes. all 3 lights were on, brake, abs and svs. so if both rear sensors are bad, lets see where the wiring goes. tah dah, wiring harness to rear bulkhead connector. ordered a new wiring harness for that, like $28, came with clips and everything installed in all the right locations, go to take old one out and what did i find...a bunch of water and trash was held up in the wire loom. I think this is the root cause of alot of these types of failures. so i took the old harness out, put the new one in, before i plugged the new one in, put di-electric grease in the connector plugs, plugged them in, and its Ronco Time...set it and forget itno problems since, that was 8 months ago, also cuz a few holes in the loom to drain the water so it wont set up.

[Metallman56]

does anyone know of a national chain that can scan the SVS light for free? also, so far in this post, that i have read, there are a lot of things that seem to cause this problem.

Tire Presure
Wheel Hub
Rear Wiring Harness
Front Left Speed Sensor
Front Right Speed Sensor
Bad/Dirty Connection on the Speed Sensor.

[gectek]

there is an easy way to test the wheel speed sensors. disconnect the wheel speed sensor(s) and check for the resistance on the sensor itself. the resistance should be between 1000 Ohms and 1200 Ohms. if that is good, life the vehicle and turn the tire fairly fast, book says 1 rev per second, and measure the voltage output in millivolts, it should be more than 100mV at that speed. if it doesnt measure that then replace the WSS.

if it does then you are on to checking the power and ground to the EBCM and the WSS harness side. it is alot easier to have the code read by a technician with a good scan tool, that way you can tell which sensor/wiring you are looking at

[GrandSlamGT]

Well this has just started happening with my 2002 GT. I only have 65k miles on it. I recently replaced pads and rotors on the car. A couple months later now both lights are on (ABS and Trac Off). I can hear a slight humming, almost not noticable above 45mph so I'm sure a hub assembly is going south. Also when I go to brake while in slow traffic, such as in town, I will get a loud buzz and my brake pedal will push back on me. When this happens, my lights immediatly come on. It seems this is a very common problem, and I think GM should do something about this.

Originally Posted by windwin

I got a same problems on my Grand AM GT 1999.
Anybody can share more details for DIY.
SVS/ABS/TRAC off lights are on.
so, dear eaglesrealm, would you give me suggestion for repair myself?
Thanks a lot

ahhh the good old n-body wheel bearing trubles...all of these complaints are all prity much the same.. most of the time the fix is replace the wheels beraring hub kit....but this wont always work..the good old grand ams have an ebcm witch is located behind the front left fender skirt this is a really bad place for carrosion....so u might wanna pull back the skirt and see what the connector and everthing is like...all it may be in the sensor harness. so u could do a check on that. anyways heres a flow chart to help find the problem.....if u guys need anyother codes check or any questions just e-mail me at blundon_19@hotmail.com



DTC C1226 RF Excessive Wheel Speed Variation




Circuit Description
As a toothed ring passes by the wheel speed sensor, changes in the electromagnetic field cause the wheel speed sensor to produce an AC voltage signal. The frequency of the AC voltage signal is proportional to the wheel speed. The amplitude of the AC voltage signal is directly related to wheel speed and the proximity of the wheel speed sensor to the toothed ring. The proximity of the wheel speed sensor to the toothed ring is also referred to as the air gap.

Conditions for Setting the DTC
DTC C1226 can set when the brake is OFF.

DTC C1226 detects a situation in which the right front wheel acceleration or deceleration is beyond specified limits.

Action Taken When the DTC Sets
A malfunction DTC stores.
The ABS disables.
The ABS warning indicator turns ON.
Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
100 drive cycles pass with no DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition OFF.
Diagnostic Aids
The following conditions may cause an intermittent malfunction:

A poor connection
Rubbed-through wire insulation
A broken wire inside the insulation
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction.

If the customer's comments reflect that the amber ABS warning indicator is ON only during moist environmental changes (rain, snow, vehicle wash), inspect all the wheel speed sensor circuitry for signs of water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure:

Spray the suspected area with a five percent saltwater solution. Add two teaspoons of salt to twelve ounces of water to make a five percent saltwater solution.
Test drive the vehicle over various road surfaces (bumps, turns, etc.) above 24 km/h (15 mph) for at least 30 seconds.
If the DTC returns, replace the suspected harness.
Thoroughly inspect any circuitry that may be causing the intermittent complaint for the following conditions:

Backed out terminals
Improper mating
Broken locks
Improperly formed or damaged terminals
Poor terminal-to-wiring connections
Physical damage to the wiring harness
Resistance of the wheel speed sensor will increase with an increase in sensor temperature.

Use the following procedure when replacing a wheel speed sensor or harness:

Inspect the wheel speed sensor terminals and harness connector for corrosion and/or water intrusion.
The wheel speed sensor and jumper harness should be replaced if evidence of corrosion or water intrusion exists.
Test Description
This test checks the wheel speed sensor for the proper resistance value.

This test ensures that the wheel speed sensor generates the proper voltage.

This test checks for a short between the wheel speed sensor high and low circuits.

This test determines if a wheel speed sensor circuit could be shorted when the EBCM is connected.

Step
Action
Value(s)
Yes
No

Important: Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual.


Important: Difficulty may occur when trying to locate intermittent malfunctions in the wheel speed sensor circuit.
Do not disturb any of the electrical connections. Change the electrical connections only when instructed to do so by a step in the diagnostic table.


1
Was the ABS Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check - ABS

2
Turn the ignition switch to the OFF position.
Inspect the right front wheel speed sensor and the right front wheel speed sensor harness connector for physical damage.
Is there any physical damage?
--
Go to Step 16
Go to Step 3

3
Inspect the following components for physical damage:

• The right front wheel speed sensor jumper harness

• The right front wheel speed sensor jumper harness connectors

Is there any physical damage?
--
Go to Step 15
Go to Step 4

4
Disconnect the right front wheel speed sensor directly at the right front wheel speed sensor connector.
Use the J 39200 with the J 35616 in order to measure the resistance between the right front wheel speed sensor connector terminal A and the right front wheel speed sensor connector terminal B.
Is the resistance within the specified range?
1040-1160 ohms
Go to Step 5
Go to Step 16

5
Select the A/C VOLTAGE scale on the J 39200 .
Spin the right front wheel by hand while observing the voltage reading on the J 39200 .
Is the voltage equal to or greater than the specified voltage?
100 mV
Go to Step 6
Go to Step 16

6
Disconnect the EBCM connector.
Use the J 39200 with the J 35616 in order to measure the resistance between the EBCM connector terminal 9 and the EBCM connector terminal 22.
Is the resistance within the specified range?
OL

(Infinite)
Go to Step 7
Go to Step 8

7
Inspect the EBCM connector for the following conditions:
- Damage

- Poor terminal contact

- Terminal corrosion (These conditions may cause a short between the EBCM connector terminal 9 and the EBCM connector terminal 22.

Inspect the remaining terminals of the EBCM connector for the following conditions:
- Damage

- Poor terminal contact

- Terminal corrosion

Are there signs of poor terminal contact, corrosion, or damaged terminals?
--
Go to Step 12
Go to Step 8

8
Inspect the wiring of CKT 872 and CKT 833 for signs of damage that may cause a short between CKT 872 and CKT 833.

Are there any signs of damaged wiring?
--
Go to Step 13
Go to Step 9

9
Inspect the harness connectors of CKT 872 and CKT 833 for signs of damage that may cause a short between CKT 872 and CKT 833.

Are there any signs of damaged connectors?
--
Go to Step 14
Go to Step 10

10
Reconnect the EBCM harness connector.
Reconnect the right front wheel speed sensor harness connector.
Install a Scan Tool .
Test drive the vehicle at a speed above 24 km/h (15 mph) for at least 30 seconds.
Use the Scan Tool in order to read the DTCs.
Does DTC C1226 set as a current DTC?
--
Go to Step 11
Go to Step 18

11
Select the Data Display on the Scan Tool .
Select ABS Data.
Monitor the wheel speed sensor speeds.
Use the following procedure to drive the vehicle when testing the wheel speed sensor:
Slowly accelerate to 65 km/h (40 mph).
Slowly decelerate to 0 km/h (0 mph).
Is the speed of the right front wheel speed sensor constantly higher or lower than the speed of the three remaining wheel speed sensors?
--
Go to Step 16
Go to Step 17

12
Replace all of the terminals that exhibit signs of poor terminal contact, corrosion, or damaged terminal(s). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check - ABS
--

13
Replace the damaged wiring harness that causes the short between CKT 872 and CKT 833. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check - ABS
--

14
Replace the damaged wiring harness connectors that cause the short between CKT 872 and CKT 833. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check - ABS
--

15
Replace the right front wheel speed sensor jumper harness. Refer to Wheel Speed Sensor Jumper Harness Replacement .

Is the repair complete?
--
Go to Diagnostic System Check - ABS
--

16
Replace the right front wheel speed sensor. Refer to Wheel Speed Sensor Replacement .

Is the repair complete?
--
Go to Diagnostic System Check - ABS
--

17
Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Is the repair complete?
--
Go to Diagnostic System Check - ABS
--

18
The malfunction is intermittent or is not present at this time.

Refer to Diagnostic Aids for more information.

Is the action complete?
--
System OK
--



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