Abs lights stay on, local mechanic said a code comes up for rear speed sensors

You need a mechanic with a high level scan tool to check the Diagnostic Trouble Codes and Live Data. It is probably ABS Sensor related, but should never leave you with no brakes..

The brake and abs light come on if a problem is detected. When the abs light is on the abs is NOT working. You need to pull the codes from the ecm to detect the problem

Hi, there is a speed sensor causing your problem which is the one on the top of the rear differential. Its the one that runs the speedometer, picked up by the abs module. The abs is disabled if the light is on, your brakes will stayed locked if you start to slide.



I'd start with replacing the rear speed sensor and see what happens. This should bring your speedometer back if nothing else. If you still have the other code coming back you'll have to replace the abs control module. That code is a direct internal failure of the control module, no diagnostics required.

Hi!!
When Yellow ABS warning light illuminates during normal operation, the system has detected a problem and has stored a Diagnostic Trouble Code (DTC). Loss of power to module will cause system to be deactivated and Yellow ABS warning light to be illuminated. This fault will not set a DTC.
The Rear Anti-Lock Brake System II (RABS II) Speed Sensor is located on the Rear Differential Case. This sensor sends the speed signal of the rear tires to the RABSII Control Module, which also receives the Turbine Shaft Speed Sensor. The RABSII Control Module uses both signals to control the RABS II Proportioning Valve. If the RABSII Control Module does not receive both signals, the ABS Light will come ON.
Finally, the Sensor I think is giving you trouble. The Turbine Shaft Speed (TSS) Sensor is located on the transmission tail. This sensor sends the speed signal to the PCM which in turn sends it to the Speedometer and to the RABSII Module. If this sensor is disconnected or inoperative, the Speedometer won't work and the ABS light will come ON. Check electrical connector to the sensor, make sure is clean, free of corrosion and properly connected.
Before you replace the sensor, have the computer codes scanned for FREE at AutoZone, Checkers or similar autoparts store.
Good Luck!! A HELPFUL - 4 THUMBS - rating for this solution would be greatly appreciated. Thank you for using FixYa.

99% Bad ABS Module.

Unless you have a cut ABS wheel sensor.
I fix them my self.

[email protected]

You need to have an abs code scanner hooked up to it to find out why the light is on. If there is an advanced auto or an autozone parts store near you, go there, they can hook up one for free, takes about a minute, if not, you'll have to pay somewhere else, and it isn't cheap.

ABS SPEED SENSOR

check your wheel speed sensors unplug them and use an ohm meter across the 2 terminals and the one that is diff from the others needs to be replaced

This isn't hard to do at all really and should be easy to procure the part from the local parts store. There is only one little screw holding it in

1. Raise and support vehicle.
2. 
   NOTE: Clean off dirt and foreign material that may have collected around the rear anti-lock brake sensor before removal. Remove the rear anti-lock brake sensor.

1 Disconnect the rear anti-lock brake sensor electrical connector. 2 Remove the bolt. 3 Remove the rear anti-lock brake sensor.

1. NOTE: Thoroughly clean the mounting surface. NOTE: Inspect the anti-lock brake sensor O-ring for damage; lightly lubricate the O-ring with axle lubricant. To install, reverse the removal procedure

ABS light comes on with ignition then should go off when you start the car.
If abs sensor does not turn off after disconnecting the battery, then there is a real problem, a faulty sensor or ABS malfunctioning.
When the ABS led comes on immediately after you start the car and stays on usually is one of the relays.
The main one is called surge arrester relay, if it is faulty usually there have been an overvoltage.
There should be two more, usually located behind the black plastic cover of the ABS.
Testing and changing the faulty relay can fix the problem.

If light turns off on startup, and comes back on when you reach some speed, usually you need to check the wheel sensors. You test them unplugging the sensor located behind the wheel and testing it for continuity with a multimeter.
Use Haynes manual to find locations and specs of relays.
Contact a qualified mechanic if you cannot fix it yourself, problems with ABS may compromise safety of the vehicle.