08 Ford Taurus X SEL ABS speed sensor code

[movaughn]

I got a right front speed sensor code and changed the speed sensor and the code is still showing. I don’t have a repair manual for the wagon and can’t find any info or diagrams on where or what I should be looking for. Any help would be appreciated. I take it that the right front is the passenger side. I have been working on this for the past 3 Saturdays. I have disconnected the battery for 10 minutes but the code is still there.

[Crvett69]

you may need to have the code reset with a code scanner. usually unhooking battery won't clear them. if you still get the same code either the wire after the sensor is bad or something is wrong with your sensor ring on the axle/hub. you can unplug the new sensor and make sure its still good with a ohm meter. can also spin the wheel and see if the resistance changes when you spin the wheel or switch it to lowest voltage setup and see if it shows a small voltage when wheel spins

[shorod]

What was the particular diagnostic code number? There is more than one "right front speed sensor" code.

-Rod

[movaughn]

Thanks will do a resistance check tomorrow there were no codes just " right front ABS speed sensor error message."

[movaughn]

Hey Rod,

The code is C1297 right front wheel speed sensor input fault with the Innova OBD2 - 303 scanner. I had no time on Saturday other than reading the code and resetting it. The scanner reset the code but it came back. I can't even find a manual for this SUV or wagon.

[shorod]

If you'd like a PDF file of the diagnostic procedure for the C1297 code, send me a Private Message with the request AND an e-mail address for you.

From the factory service manual:
Pinpoint Test C: DTCs C1222, C1296, C1297, C1298 and C1299 — Wheel Speed Sensor Signal Fault

Refer to Wiring Diagrams Cell 42 , Vehicle Dynamic Systems for schematic and connector information.
Normal Operation

The wheel speed sensor and sensor ring generates a square wave current signal to the ABS module that is proportional to the wheel speed. The ABS module compares the wheel speed inputs from all the wheel speed sensors to determine an impending wheel lockup. Incorrect tire size can set these DTCs as well.



Code Description: DTC C1297 RF Wheel Speed Sensor Signal Fault

Fault Trigger Condition: When the vehicle speed exceeds 20 km/h (12 mph), if the ABS module does not receive a signal from the wheel speed sensor, the appropriate DTC will be set. These DTCs can also be set by an excessive wheel speed sensor-to-tone ring air gap or a damaged tone ring.

• This pinpoint test is intended to diagnose the following:
• ABS module
• Wheel speed sensor ring
• Wheel speed sensor

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Since you've already replaced the sensor, carefully checking the tone ring for the passenger side front wheel and checking the condition of the wiring for the sensor would be practical next steps.


-Rod

[movaughn]

Hey Rod, Just spent all day working on it. I removed the bearings cleaned it up along with the wheel speed sensor housing and I still get the fault. What does the speed sensor ring look like. Is that the piece that is on the inside of the bearings? What voltage, resistance or signal should I get from the wires of the speed sensor to identify that there is a short. When would I be able to read that, when the car is on or when the wheels are spinning.

Thanks Again

[shorod]

I don't have first hand experience on the Taurus X. The tone ring could look like a toothed ring mounted on the half shaft (aka: axle), it could look like a toothed ring on the bearing, or it could look like a non-metallic washer that goes between the bearing and the half shaft.

If it looks like a toothed ring, you'll want to carefully inspect that ring to make sure that all of the teeth are in tact and not chipped. You'll also want to inspect the valleys of the teeth for any cracks and/or separations between teeth.

If you happen to have access to an oscilloscope, that would be the best way to test the components. With the key in the Run position and the scope backprobing the signal lead of the sensor, spin the wheel at a constant rate and make sure the scope displays a square wave of uniform duty cycle and frequency. If you don't have an oscilloscope you can use a multimeter set to VAC and do a similar test, watching for a constant voltage (versus a constant square wave). A third method would be to use a professional scan tool to monitor the wheel speed sensor reading. This won't help you determine though if you have a sensor issue versus a wiring issue assuming the speed sensor does not report a reading on the scan tool.

Assuming you are able to perform one of the meter tests above and do not see a signal, that would suggest that either the sensor or tone ring is an issue. If you do see a constant signal though, that would suggest there's a problem between the connector for the speed sensor and the ABS module.

-Rod

[movaughn]

Thanks Rod,

I will give it another look on Saturday.

Vaughn

[movaughn]

Hey Rod,

Rod,

Thanks to you and all the others that helped me I fixed the problem yesterday. The problem was the new rotor that I put on months ago was the wrong one. I took the rotor off from the other side and compared it to the side that was giving me the error code and it was different so I had to buy another one. So I spent $400 when all I should have spent was $150 to replace the rotor and months of working on the car. My ABS works and I can stop now.

Vaughn

[shorod]

Interesting find. Thank you for following up with what you discovered!

-Rod