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Hey waynep7122 Question about brakes

 
ethelkilledfred-#001
I mow my lawn and find Chevys
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Posted: 04/14/11 08:24 PM

I'm going through front brakes at an alarming rate on my 99 Suburban. I was told it is a common problem on these trucks. The front disc brakes are too small on this truck and they run hot killing the brake fluid and thus giving a false reading to the anti lock computer causing the brakes to stick. I change and flush the fluid and that has been working, but I'm getting sick of it. I disconnected the brake computer and already see a difference in the way the truck stops, it stops normal now like a older truck does and does not feel like I'm towing a trailer when I take off. My question is what is the ill effects of running the computer disconnected? Thanks  
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waynep7122
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Posted: 04/14/11 09:19 PM

do you have the 1/2 ton.. or the 3/4 ton version...

how fast are you going through rear brakes???/  

can you lock up all 4 in a panic stop with the ABS fuse pulled..?????

can you make all 4 wheels chatter/chirp when you do a panic stop with the fuse in..   the ABS light comes on when the system is active...  


GM trucks in the early 90s had sensor problems...   what...

the reluctors spin with the wheel speed... creating voltage in the wheel sensors...  the faster the wheels spin. the higher the voltage...   so the wheels should all make very close to the same voltage...

when one sensor failed... it would sometimes create spikes as the truck slowed down..  the wheel with the bad sensor would create a higher voltage than the other wheels..   the antilock computer would think that the other wheels were starting to slip... so it would isolate them and release the pressure to try to match the incorrect speed sensor..

question... do you have the same rear end ratio????  where is the ABS speed sensor on the rear axle???? at the wheels.. or at the diff...  when at the diff.. if you change the gear ratio... or have larger tires on the drive axle than the front wheels.. you create different voltages causing the slower wheels to become isolated and pressure past the isolation valve released..

this puts tremendous pressure on the front brakes...

i don't have an ABS cartridge for my OTC Extended monitor...

you might want to look at the autel unit that has just been released...  its like the harbor freight 98614.. but it will access ABS also..

http://www.auteltech.com/ms609.htm   i have not searched out who sells this yet... the MS509 is the same as the 98614..

question.. does the abs light come on during normal braking with your truck...  it should ONLY come on during start up as a bulb test...

i wonder how many times a week you drive past my house... and never know it..   i am sitting here looking at the GIF at the bottom of your post.. and remember all the great nights at TI..  nights... actually whole weekends....  some creative digital editing might make the what looks like a 240z that did not move.. blow past mannys mustang as he sets the front end down..


last thing...   AZ used to sell the carbon metallic brand brake pads... in the blue box...   they lasted about 3 or 4 times longer than conventional pads on overworked GM cars ..  

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ethelkilledfred-#001
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Posted: 04/15/11 12:35 AM

Anti-lock does not work, truck at low speed has slid through an intersection on a panic stop, and brakes have faded and not stopped other times. I drive it like I'm towing when I'm not towing to avoid panic stops. Brakes seem to be working better. Brakes make a grinding noise when brakes are not applied but noise goes away when brake are applied. Noise is coming from brakes not releasing completely and eventually you can smell the brakes and see the heat off of them. Before I got it brakes were done 6 months before and 3 months previous. Then I did the brakes and were replaced and lasted 2 months. Brakes were replaced again and bled and flushed brake fluid and have lasted 3 months so far. Right now with it disconnected it stops better, less fade and fronts lock up on dirt road in panic stop.



1/2 ton five lug light weight truck is all stock

DSC04421

ABS light on all the time but now it's off since unplugged

DSC04792


Unplug from here-


DSC04876
DSC04871
DSC04874  
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ethelkilledfred-#001
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Posted: 04/15/11 12:37 AM

Icon Quotewaynep7122:

i wonder how many times a week you drive past my house... and never know it..   i am sitting here looking at the GIF at the bottom of your post.. and remember all the great nights at TI..  nights... actually whole weekends....  some creative digital editing might make the what looks like a 240z that did not move.. blow past mannys mustang as he sets the front end down..




I'll be going to LA tomorrow between noon and three, pm and I'll stop by before or if it's not too late after on the way home.  
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Skylark
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Posted: 04/15/11 02:49 AM

Man that is Kool that 2 of the Best on here live in the same neighborhood.  

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redneckjoe69
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Posted: 04/15/11 07:35 AM

Icon Quoteethelkilledfred:
Anti-lock does not work, truck at low speed has slid through an intersection on a panic stop, and brakes have faded and not stopped other times. I drive it like I'm towing when I'm not towing to avoid panic stops. Brakes seem to be working better. Brakes make a grinding noise when brakes are not applied but noise goes away when brake are applied. Noise is coming from brakes not releasing completely and eventually you can smell the brakes and see the heat off of them. Before I got it brakes were done 6 months before and 3 months previous. Then I did the brakes and were replaced and lasted 2 months. Brakes were replaced again and bled and flushed brake fluid and have lasted 3 months so far. Right now with it disconnected it stops better, less fade and fronts lock up on dirt road in panic stop.



1/2 ton five lug light weight truck is all stock

DSC04421

ABS light on all the time but now it's off since unplugged

DSC04792


Unplug from here-


DSC04876
DSC04871
DSC04874


sounds like your calipers are "sticking".  once they get hot,...your gonna have a soft pedal & that burnt smell.  have you tried replacing the calipers?   dot 4 or 5 brake fluid may help with the boiling point of your fluid, but i'd make sure it's compatable first.  

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waynep7122
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Posted: 04/15/11 07:56 AM

if the ABS light is ON constantly.. there is a problem with the ABS...

the abs light should ONLY be  on during the bulb check when starting .. and when you have your foot planted hard on the brakes in a panic stop....

log in check PM.. i will post my contact info there..

but i don't have a scan tool that will talk to the antilocks .. and when the system is unplugged  ..  it looses any codes...

it takes a decent scan tool.. almost any  of the newer ones with a color screen.  or a tech 2...  to really examine the antilocks...

i should be able to extract codes somehow..   we will see ...  i will have to whip out my HF and OTC scanners.. see what  i can find....  

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waynep7122
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Posted: 04/15/11 08:09 AM

here is a list of the possible codes...

C0000 - Vehicle Speed Information Circuit Malfunction
C0035 - Left Front Wheel Speed Circuit Malfunction
C0040 - Right Front Wheel Speed Circuit Malfunction
C0041 - Right Front Wheel Speed Sensor Circuit Range/Performance (EBCM)
C0045 - Left Rear Wheel Speed Circuit Malfunction
C0046 - Left Rear Wheel Speed Sensor Circuit Range/Performance (EBCM)
C0050 - Right Rear Wheel Speed Circuit Malfunction
C0051 - LF Wheel Speed Sensor Circuit Range/Performance (EBCM)
C0060 - Left Front ABS Solenoid #1 Circuit Malfunction
C0065 - Left Front ABS Solenoid #2 Circuit Malfunction
C0070 - Right Front ABS Solenoid #1 Circuit Malfunction
C0075 - Right Front ABS Solenoid #2 Circuit Malfunction
C0080 - Left Rear ABS Solenoid #1 Circuit Malfunction
C0085 - Left Rear ABS Solenoid #2 Circuit Malfunction
C0090 - Right Rear ABS Solenoid #1 Circuit Malfunction
C0095 - Right Rear ABS Solenoid #2 Circuit Malfunction
C0110 - Pump Motor Circuit Malfunction
C0121 - Valve Relay Circuit Malfunction
C0128 - Low Brake Fluid Circuit Low
C0141 - Left TCS Solenoid #1 Circuit Malfunction
C0146 - Left TCS Solenoid #2 Circuit Malfunction
C0151 - Right TCS Solenoid #1 Circuit Malfunction
C0156 - Right TCS Solenoid #2 Circuit Malfunction
C0161 - ABS/TCS Brake Switch Circuit Malfunction
C0221 - Right Front Wheel Speed Sensor Circuit Open
C0222 - Right Front Wheel Speed Signal Missing
C0223 - Right Front Wheel Speed Signal Erratic
C0225 - Left Front Wheel Speed Sensor Circuit Open
C0226 - Left Front Wheel Speed Signal Missing
C0227 - Left Front Wheel Speed Signal Erratic
C0229 - Drop Out of Front Wheel Speed Signals
C0235 - Rear Wheel Speed Signal Circuit Open
C0236 - Rear Wheel Speed Signal Circuit Missing
C0237 - Rear Wheel Speed Signal Erratic
C0238 - Wheel Speed Mismatch
C0241 - EBCM Control Valve Circuit
C0245 - Wheel Speed Sensor Frequency Error
C0254 - EBCM Control Valve Circuit
C0265 - EBCM Relay Circuit
C0266 - EBCM Relay Circuit
C0267 - Pump Motor Circuit Open/Shorted
C0268 - Pump Motor Circuit Open/Shorted
C0269 - Excessive Dump/Isolation Time
C0271 - EBCM Malfunction
C0272 - EBCM Malfunction
C0273 - EBCM Malfunction
C0274 - Excessive Dump/Isolation Time
C0279 - Powertrain Configuration Not Valid
C0281 - Brake Switch Circuit
C0283 - Traction Switch Shorted to Ground
C0284 - EBCM Malfunction
C0286 - ABS Indicator Lamp Circuit Shorted to B+
C0287 - Delivered Torque Circuit
C0288 - Brake Warning Lamp Circuit Shorted to B+
C0290 - Lost Communications With PCM
C0292 - Lost Communications With PCM
C0291 - Lost Communications With BCM
C0297 - Powertrain Configuration Data Not Received
C0298 - Powertrain Indicated Traction Control Malfunction
C0300 - Rear Speed Sensor Malfunction
C0305 - Front Speed Sensor Malfunction
C0306 - Motor A or B Circuit
C0308 - Motor A/B Circuit Low
C0309 - Motor A/B Circuit High
C0310 - Motor A/B Circuit Open
C0315 - Motor Ground Circuit Open
C0321 - Transfer Case Lock Circuit
C0323 - T-Case Lock Circuit Low
C0324 - T-Case Lock Circuit High
C0327 - Encoder Circuit Malfunction
C0357 - Park Switch Circuit High
C0359 - Four Wheel Drive Low Range (4LO) Discrete Output Circuit
C0362 - 4LO Discrete Output Circuit High
C0367 - Front Axle Control Circuit High
C0374 - General System Malfunction
C0376 - Front/Rear Shaft Speed Mismatch
C0379 - Front Axle System
C0387 - Unable to Perform Shift
C0472 - Steering Handwheel Speed Sensor Signal V Low
C0473 - Steering Handwheel Speed Sensor Signal V High
C0495 - EVO Tracking Error
C0498 - Steering Assist Control Actuator Feed Circuit Low
C0499 - Steering Assist Control Solenoid Feed Circuit High
C0503 - Steering Assist Control Solenoid Return Circuit Low
C0504 - Steering Assist Control Solenoid Return Circuit High
C0550 - ECU Malfunction - internal write / checksum malfunction
C0559 - EEPROM Checksum Error
C0563 - Calibration ROM Checksum Error
C0577 - Left Front Solenoid Circuit Low
C0578 - Left Front Solenoid Circuit High
C0579 - Left Front Solenoid Circuit Open
C0582 - Right Front Solenoid Circuit Low
C0583 - Right Front Solenoid Circuit High
C0584 - Right Front Solenoid Circuit Open
C0587 - Left Rear Solenoid Circuit Low
C0588 - Left Rear Solenoid Circuit High
C0589 - Left Rear Solenoid Circuit Open
C0592 - Right Rear Solenoid Circuit Low
C0593 - Right Rear Solenoid Circuit High
C0594 - Right Rear Solenoid Circuit Open
C0611 - VIN Information Error
C0615 - Left Front Position Sensor Malfunction
C0620 - Right Front Position Sensor Malfunction
C0625 - Left Rear Position Sensor Malfunction
C0628 - Level Control Position Sensor Circuit High
C0630 - Right Rear Position Sensor Malfunction
C0635 - Left Front Normal Force Circuit Malfunction
C0638 - Left Front Normal Force Circuit High
C0640 - Right Front Normal Force Circuit Malfunction
C0643 - Right Front Normal Force Circuit High
C0655 - Level Control Compressor Relay Malfunction
C0657 - Level Control Compressor Circuit Low
C0658 - Level Control Compressor Circuit High
C0660 - Level Control Exhaust Valve Circuit Malfunction
C0662 - Level Control Exhaust Valve Circuit Low
C0663 - Level Control Exhaust Valve Circuit High
C0665 - Chassis Pitch Signal Circuit
C0690 - Damper Control Relay Circuit Malfunction
C0691 - Damper Control Relay Circuit Range
C0693 - Damper Control Relay Circuit High
C0695 - Position Sensor Overcurrent (8 volt supply)
C0696 - Position Sensor Overcurrent (5 volt supply)
C0710 - Steering Position Signal Malfunction
C0750 - Tire Pressure Monitor (TPM) system sensor not transmitting
C0755 - Tire Pressure Monitor (TPM) system sensor not transmitting
C0760 - Tire Pressure Monitor (TPM) system sensor not transmitting
C0765 - Tire Pressure Monitor (TPM) system sensor not transmitting
C0800 - Device Power #1 Circuit Malfunction
C0896 - Electronic Suspension Control (ESC) voltage is outside the normal range of 9 to 15.5 volts

GM - Chevrolet - GMC Chassis Codes

C1211 - ABS Indicator Lamp Circuit Malfunction
C1214 - System Relay Contact or Coil Circuit Open
C1217 - Pump Motor Shorted to Ground
C1218 - Pump Motor Circuit Shorted to Voltage or Motor Ground Open
C1221 - Left Front Wheel Speed Sensor Input Signal is 0
C1222 - Right Front Wheel Speed Sensor Input Signal is 0
C1223 - Left Rear Wheel Speed Sensor Input Signal is 0
C1224 - Right Rear Wheel Speed Sensor Input Signal is 0
C1225 - Left Front Excessive Wheel Speed Variation
C1226 - Right Front Excessive Wheel Speed Variation
C1227 - Left Rear Excessive Wheel Speed Variation
C1228 - Right Rear Excessive Wheel Speed Variation
C1232 - Left Front Wheel Speed Circuit Open or Shorted
C1233 - Right Front Wheel Speed Circuit Open or Shorted
C1234 - Left Rear Wheel Speed Circuit Open or Shorted
C1235 - Right Rear Wheel Speed Circuit Open or Shorted
C1236 - Low System Supply Voltage
C1237 - High System Supply Voltage
C1238 - Brake Thermal Model Exceeded
C1241 - Variable Effort Steering Circuit Malfunction
C1242 - Pump Motor Circuit Open
C1243 - BPMV Pump Motor Stalled
C1244 - Powertrain Indicated Engine Drag Control Malfunction
C1246 - Brake Lining Wear Circuit Open
C1248 - EBCM Turned the Red Brake Warning Indicator On
C1251 - RSS Indicated Malfunction
C1252 - Left Front Normal Force Malfunction
C1253 - Right Front Normal Force Malfunction
C1254 - Abnormal Shutdown Detected
C1255 - EBCM Internal Malfunction
C1256 - EBCM Internal Malfunction
C1261 - Left Front Inlet Valve Solenoid Malfunction
C1262 - Left Front Outlet Valve Solenoid Malfunction
C1263 - Right Front Inlet Valve Solenoid Malfunction
C1264 - Right Front Outlet Valve Solenoid Malfunction
C1265 - Left Rear Inlet Valve Solenoid Malfunction
C1266 - Left Rear Outlet Valve Solenoid Malfunction
C1267 - Right Rear Inlet Valve Solenoid Malfunction
C1268 - Right Rear Outlet Valve Solenoid Malfunction
C1271 - Left Front TCS Master Cylinder Isolation Valve Malfunction
C1272 - Left Front TCS Prime Valve Malfunction
C1273 - Right Front TCS Master Cylinder Isolation Valve Malfunction
C1274 - Right Front TCS Prime Valve Malfunction
C1276 - Delivered Torque Signal Circuit Malfunction
C1277 - Requested Torque Signal Circuit Malfunction
C1278 - TCS Temporarily Inhibited By PCM
C1281 - VSES Sensors Uncorrelated
C1282 - Yaw Rate Sensor Bias Circuit Malfunction
C1283 - Excessive Time to Center Steering
C1284 - Lateral Accelerometer Sensor Bias Malfunction
C1285 - Lateral Accelerometer Sensor Circuit Malfunction
C1286 - Steering Sensor Bias Malfunction
C1287 - Steering Sensor Rate Malfunction
C1288 - Steering Sensor Circuit Malfunction
C1291 - Open Brake Lamp Switch Contacts During Deceleration
C1292 - Brake Fluid Pressure Sensor Circuit
C1293 - Code C1291 Set in Previous Ignition Cycle
C1294 - Brake Lamp Switch Circuit Always Active
C1295 - Brake Lamp Switch Circuit Open
C1296 - Brake Fluid Pressure Sensor Circuit
C1297 - PCM Indicated Brake Extended Travel Switch Failure
C1298 - PCM Class 2 Serial Data Link Malfunction
C1326 - Battery Out of Range
C1650 - RSS Control Module Fault
C1658 - RSS Control Module Calibration Fault
C1710 - Left Front Damper Actuator Short Circuit to Battery
C1711 - Left Front Damper Actuator Short Circuit to Ground
C1712 - Left Front Damper Actuator Open Circuit
C1715 - Right Front Damper Actuator Short Circuit to Battery
C1716 - Right Front Damper Actuator Short Circuit to Ground
C1717 - Right Front Damper Actuator Open Circuit
C1720 - Left Rear Damper Actuator Short Circuit to Battery
C1721 - Left Rear Damper Actuator Short Circuit to Ground
C1722 - Left Rear Damper Actuator Open Circuit
C1725 - Right Rear Damper Actuator Short Circuit to Battery
C1726 - Right Rear Damper Actuator Short Circuit to Ground
C1727 - Right Rear Damper Actuator Open Circuit
C1735 - Compressor Relay Short to Battery
C1736 - Compressor Relay Short to GND/Open Circuit
C1737 - Exhaust Solenoid Valve Short to Battery
C1738 - Exhaust Solenoid Valve Short to GND
C1743 - Speed Signal Fault
C1744 - Lift/Dive Signal Discrete Fault
C1760 - Left Front Position Sensor Input Fault
C1761 - Right Front Position Sensor Input Fault
C1762 - Left Rear Position Sensor Input Fault
C1763 - Right Rear Position Sensor Input Fault
C1768 - Position Sensor Supply Fault
C1780 - Loss of Steering Position Signal
C1782 - ICCS2 DL Left Output Short Circuit to Bat
C1783 - ICCS2 DL Left Output Short Circuit to GND
C1784 - ICCS2 DL Right Output Short Circuit to Bat
C1785 - ICCS2 DL Right Output Short Circuit to GND
C1786 - Damper Control Relay Fault
C1787 - Damper Control Relay Short to GND
C1788 - Damper Control Relay Short to Bat

each one leads to a specific page in the manual...   sometimes 2 or 3 pages...  

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waynep7122
I mow my lawn and find Chevys
Posts: 1130
Joined: 08/09
Posted: 04/15/11 08:21 AM

i did PM you but you might not have gotten it..  as its already 9 am...  

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ethelkilledfred-#001
I mow my lawn and find Chevys
Posts: 1371
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Posted: 04/15/11 12:06 PM

Icon Quotewaynep7122:
i did PM you but you might not have gotten it..  as its already 9 am...

Got it. Will get a hold of you a little later. PM sent on 411 Big Willie  
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ethelkilledfred-#001
I mow my lawn and find Chevys
Posts: 1371
Joined: 03/10
Posted: 04/15/11 09:25 PM

Icon Quoteredneckjoe69:
sounds like your calipers are "sticking".  once they get hot,...your gonna have a soft pedal & that burnt smell.  have you tried replacing the calipers?   dot 4 or 5 brake fluid may help with the boiling point of your fluid, but i'd make sure it's compatable first.

I originally thought that, but if you change the fluid and the problem goes away for a little while and then comes back. When the calipers stick my fuel mileage goes to 5 mpg or less, after the brake fluid is flushed it goes to over 16 mpg on the freeway. It is very noticeable. Since disconnecting it, it seems to be doing well, no ill effects yet.  
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tuffnuff
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Posted: 04/15/11 09:32 PM

Glad that problem got solved for ya EKF.,. thanks to Wayne the brain, man, he sure knows his stuff.

Smile  
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waynep7122
I mow my lawn and find Chevys
Posts: 1130
Joined: 08/09
Posted: 04/16/11 05:39 AM

i saved this text over a decade ago.... i knew i would need it....  i did not write it...


: Brakes just didn't stop, ABS problems.

>On every wheel speed sensor dropout that I have ever
>experienced, it has always been an intermittent open in a
>wire. Usually the RF, because it gets more turning radius
>than any other tire. Most of them that I have seen have
>been on GM's ABS VI which I think is Delco Moraine.
>Whenever I see a wheel speed sensor code, the first thing
>that I do, whether a hard code or an intermittent code, is
>to go to the control module and do a resistance check of
>the suspect sensor, or in the case of an intermittent, no
>code problem, all of the sensors. IMPORTANT This must be
>done before the car is put on the lift. Any movement of the
>suspension can/will change a wiring problem. If all sensors
>check good, and no codes, I would then procede to raise the
>car and recheck my resistances. If all resistances are
>good, the next test that you can do is to disconnect the
>sensors, visually inspect for terminal fit/drag, and any
>corrossion. I have seen sensor circuits that failed a
>resistance test, and simply touching the outside of the
>connector had fixed the car. In that instance, nothing that
>I could do would recreate that senario. It just had poor
>contact at the terminal to blade connection. Now, that all
>of the sensor circuits have been checked with an ohmeter,
>you can proceed to load test the wires. I normally do this
>with a test light (not a high impedence light) You must use
>something that draws some amperage. It would be best to use
>a light big enough to completely load the circuit, but not
>so large as to overload the wires. Your control module must
>be disconnected, as well as you wheel speed sensors. Now
>run jumper wires to one end, and hook your test light to
>the other end so that it is on. With the circuit loaded in
>this manner, you can now proceed to do and extensive
>"wiggle" test of the harness, paying particular attention
>to the bends at the wheels. When I say extensive wiggle
>test, that is exactly what I mean. Spend a lot of time, and
>wiggle every inch of harness. First do a quick once over,
>then come back and do every inch. Almost if not all of mine
>have been at the bend on the RF of the vehicle, as the wire
>bends more there than at any other place on the car. Also
>keep in mind that it only takes one strand of copper to
>complete the circuit, so thouroughly loading the wire is a
>neccessity. And do not take your eye off of that light even
>for a split second. Have a helper if neccessary. After
>doing this, you can be certain that the wheel speed sensor
>wiring is intact. Lots of these break right at the terminal
>to wire connection as well, so remember to pull on the
>wires during your wiggle test. Hope this helps, and don't
>forget to check for any bulletins concerning this problem.

Scott, instead of doing all this work, just take a test
drive with the tech 2 first and run two full snapshots
during normal driving. The problem does not necessarily
have to occur nor do you have to use the brake. Play back
your snapshots and graph your wheel speed sensors. Many
times you will see the problem allowing you to concentrate
your efforts on one sensor circuit only. Often, the bad
sensor and/or harness will be noticable at higher speeds
even though ABS has not been accuated due to the brake not
being used.

I had a 1994 Jimmy come in. The complaint was that at
times, the brake pedal felt hard and the truck would not
stop. I thought of two possibilities : The EGR was sticking
open and the pedal was hard due to low manifold vacuum or a
wheel speed sensor problem. There were no codes stored for
the EFI or the ABS system so I discounted the EGR as a
likely possibility and road tested to snapshot wheel speed
sensors. This is a normal snap of low speed braking.

Normal Operation

I drove for 10 minutes and couldn't make anything happen.
Returning to the shop, making my last stop before turning
in, behind several cars, I heard the ABS pump come on and
the truck didn't want to stop. If not for 2 feet on the
brake pedal and a sudden swerve into the breakdown lane, I
would have harpooned the car in front of me. My hands were
shaking for 10 minutes afterwards. I played back my
snapshot and saw this when the fault occurred.

Easy to see the problem

What if the problem didn't occur for me? I played back my
snaps and saw this when traveling at 50 mph or so without
touching the brake.

Same sensor

So, even if I didn't get scared out of my wits, I still
would have known which sensor circuit to diagnose. A new
R.F. wheel speed sensor saved the day.  

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