My anti lock warning comes on after 1 mile of driving. If I test the anti lock on ice during the first mile the system works fine, around 1 mile the lamp lights. Any ideas ?
Probably one of the ABS sensors has bone bad. Since your car probably doesn’t have OBD II diagnostics, they’ll have to all be tested one by one.
@GeorgeSanJose OBD 2 diagnostics doesn’t have anything to do with ABS. That is an entirely different ball game.
Like you, though, I suspect that one of the wheel speed sensors is bad.
Here’s what I would do.
Put the car on jackstands.
Measure the resistance of all sensors. If the RF sensor has sky high resistance compared to the LF sensor, it’s probably faulty. Same goes for the rear, although I’m not sure if you have 3 or 4 sensors. A lot of older cars only have 3 sensors (LF, RF and rear)
Spin the wheels as fast as you can and measure the AC voltage of all sensors. If one sensor has very low AC voltage compared to the others, that’s the one to look at. Perhaps you just have a dirty tone ring. A good sensor will easily produce over 600 millivolts AC.
@db4690 … I think I read on a prior thread here on CarTalk that on some cars at least the OBD II can be used to at least partly diagnose ABS wheel sensors. For the OP’s car though, I concur, your method is the one to use.
I did a quick Google search and came up w/the following. Is this How To info correct or bogus?
“The ABS control module on the 2000 Ford E-150 is connected through the OBDII or on board diagnostics computer. Testing and ABS sensor can be done through the OBDII port, as each wheel sensor is connected to the OBDII computer through the ABS control module.”
How to Test a 2000 Ford E-150 Abs Wheel Sensor
@GeorgeSanJose I see why you believe that OBD2 has something to do with ABS diagnosis.
The 16-pin D shaped DLC is indeed needed . . . to hook up your scanner. At that point, you choose which control module you want to communicate with (PCM, BCM, ICM, ABS, etc)
Note that a cheapo $100 code reader probably won’t even communicate with SRS, ABS, BCM, etc.
ABS is not legally required to be accessible using a generic OBD2 code reader or scan tool.
I will say this: It is possible that the generic OBD2 data will display wheel speed. But it generally won’t display wheel speed at a specific sensor. In other words, you won’t know what sensor is providing that bit of data.
I read that link that you provided. It was pretty good info, but it was kind of generic.
FWIW . . . I’m not a big fan of ehow.com . . . everything is pretty vague. There are often no pictures provided, etc. I may be mistaken, but I believe the ehow contributors are paid on commission. The more articles they write, the more they earn. I believe it’s in their best interests to write as many as possible. It’s all about quantity, not quality. I have heard that in some cases, the writers that write these articles had no clue about the particular subject matter before receiving the commission. Then they had to quickly gather enough info online in order to write a brief article.
I certainly hope I’m not offending anyone here.
I’m just reporting what I heard. On more than one occasion.
With the utmost respect,
* DTC C0000 Vehicle Speed Information Circuit Malfunction
* DTC C0035 LF Wheel Speed Circuit Malfunction
* DTC C0040 RF Wheel Speed Circuit Malfunction
* DTC C0045 LR Wheel Speed Circuit Malfunction
* DTC C0050 RR Wheel Speed Circuit Malfunction
* DTC C0060 LF ABS Solenoid #1 Circuit Malfunction
* DTC C0065 LF ABS Solenoid #2 Circuit Malfunction
* DTC C0070 RF ABS Solenoid #1 Circuit Malfunction
* DTC C0075 RF ABS Solenoid #2 Circuit Malfunction
* DTC C0080 LR ABS Solenoid #1 Circuit Malfunction
* DTC C0085 LR ABS Solenoid #2 Circuit Malfunction
* DTC C0090 RR ABS Solenoid #1 Circuit Malfunction
* DTC C0095 RR ABS Solenoid #2 Circuit Malfunction
* DTC C0221 RF Wheel Speed Sensor Circuit Open
* DTC C0222 RF Wheel Speed Signal Missing
* DTC C0223 RF Wheel Speed Signal Erratic
* DTC C0225 LF Wheel Speed Sensor Circuit Open
* DTC C0226 LF Wheel Speed Signal Missing
* DTC C0227 LF Wheel Speed Signal Erratic
* DTC C0229 Drop Out of Front Wheel Speed Signals
* DTC C0235 Rear Wheel Speed Signal Circuit Open
* DTC C0236 Rear Wheel Speed Signal Circuit Missing
* DTC C0237 Rear Wheel Speed Signal Erratic
* DTC C0238 Wheel Speed Mismatch
* DTC C0245 Wheel Speed Sensor Frequency Error
* DTC C0286 ABS Indicator Lamp Circuit Shorted to B+
* DTC C0288 Brake Warning Lamp Circuit Shorted to B+
* DTC C0300 Rear Speed Sensor Malfunction
* DTC C0577 Left Front Solenoid Circuit Low
* DTC C0578 Left Front Solenoid Circuit High
* DTC C0579 Left Front Solenoid Circuit Open
* DTC C0582 Right Front Solenoid Circuit Low
* DTC C0583 Right Front Solenoid Circuit High
* DTC C0584 Right Front Solenoid Circuit Open
* DTC C0587 Left Rear Solenoid Circuit Low
* DTC C0588 Left Rear Solenoid Circuit High
* DTC C0589 Left Rear Solenoid Circuit Open
* DTC C0592 Right Rear Solenoid Circuit Low
* DTC C0593 Right Rear Solenoid Circuit High
* DTC C0594 Right Rear Solenoid Circuit Open
* DTC C1211 ABS Indicator Lamp Circuit Malfunction
* DTC C1221 LF Wheel Speed Sensor Input Signal is 0
* DTC C1222 RF Wheel Speed Sensor Input Signal is 0
* DTC C1223 LR Wheel Speed Sensor Input Signal is 0
* DTC C1224 RR Wheel Speed Sensor Input Signal is 0
* DTC C1225 LF Excessive Wheel Speed Variation
* DTC C1226 RF Excessive Wheel Speed Variation
* DTC C1227 LR Excessive Wheel Speed Variation
* DTC C1228 RR Excessive Wheel Speed Variation
* DTC C1232 LF Wheel Speed Circuit Open or Shorted
* DTC C1233 RF Wheel Speed Circuit Open or Shorted
* DTC C1234 LR Wheel Speed Circuit Open or Shorted
* DTC C1235 RR Wheel Speed Circuit Open or Shorted
I’ve never personally accessed or used these chassis codes, but the capability would appear to exist. Where (on what cars) I know not, and It respect and bow to your experience. I also believe that many of these are “self checks” failures on start up. A failure should trip the ABS warning light.
Whoops…I just realized the subject car is a 1991 vehicle. No OBDII there.
A speed sensor with an open circuit or excessive resistance will fail the “self check”
A dirty tone ring won’t set the light until the vehicle’s moving down the road and the control module sees a problem.
Those are chassis codes, as you yourself stated.
There is no law that requires chassis codes to be retrievable by a generic/aftermarket OBD2 scan tool or code reader
The same goes for airbag and so on.
The law DOES require that PCM codes be retrievable by a generic/aftermarket OBD2 scan tool or code reader.
Again, the only thing that ABS and OBD2 have in common are that you connect to the same 16 pin DLC. But to communicate with the ABS module, you choose ABS, not PCM. If your tool can do that.
Db, everything you say is true. However, my point was that ABS codes are stored in OBDII systems and retreivable, albiet with a capable scanner. However, it’s a moot point…I didn;t realize until I’d posted that this is a pre-OBDII vehicle. I goofed anyway.