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'08 3.0R Limited Sedan; '09 Outback 3.0R
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Discussion Starter #1
I recently diagnosed a CEL P0500 Vehicle Speed Sensor issue, and the root cause wasn't the typical damaged ABS wheel sensor. I learned a lot in the process, and I wanted to share it for the next DIY'er that might run into this.

Vehicle
: 2006 Tribeca with 247,000 miles. The motor, tranny, and accessories are nearly identical to any of the H6 Outbacks and Legacys.
Symptom: CEL, cruise, along with ABS/brake dash lights. The dash also says "Err SS" which means Error Speed Sensor. The car runs in a failsafe mode where the radiator fans are always on. Vehicle is not in drivable state due to other issues so there was no information on overall drivability.
Check Engine code: P0500 Vehicle Speed Sensor

A few important things I learned:

  • You can read check engine light codes on the Tribeca using the 06-09 Legacy/Outback method described here: http://www.subaruoutback.org/forums/109-gen-3-2005-2009/19053-05-06-09-how-read-diagnostic-trouble-codes-dtcs.html
  • On Subaru's, the P0500 code does not refer to the Vehicle Speed Sensors located in the transmission. The P0500 code actually refers to part of the ABS/VDC system, and you need to retrieve secondary cruise control codes to get more info.
    • However, you cannot read C**** codes using the method from the previous bullet as the engine needs to be running for the ABS/VDC module to be responsive. When you use the method above and switch to the C**** codes, you will simply see the C---- blinking indefinitely. Not helpful!
  • The simplest way to read the C**** codes (cruise control codes) is to use FreeSSM and a Vag-com ODB2 cable.
    • You can get a cloned vag-com cable on Ebay for $8 shipped. Look for "VAG-COM KKL 409.1 OBD2"
    • With the engine running, click the "Cruise Control" tab in the engine diagnostics of FreeSSM.
    • If you use FreeSSM to look at the Cruise Control codes with the car "on" but without the motor "running", it will display only C0043, which is a bogus code. It's the "cancel code" for when the ABS/VDC module isn't responsive. It means nothing so ignore it.
So anyways, using FreeSSM with the vehicle's motor running I was able to pull C0023. I found a list of ABS/VDC C**** trouble codes somewhere on the net. I attached it here for reference:


This code pointed to the front left (drivers side) ABS wheel speed sensor. Great! That seemed like a simple fix. I decided to take a look at the speed sensor and the condition of the wiring. As I pulled the sensor out of the hub, I noticed it was all chewed up and missing chunks. The damage on the sensor was caused by the magnetic tone encoder ring on the back of the hub assembly.




Well that seemed like an obvious root cause. I ordered a new hub assembly and speed sensor, and I installed them. WRONG. It didn't fix it! I made a rookie mistake on not properly diagnosing the issue and throwing parts at it!

At this point, I found the FSM section on diagnosing Code 0023. It had me test the voltage going to the speed sensor (+12V one pin, GND on the other pin). I ohm'ed out the wiring through the various connectors on their way to the ABS/VDC module. All seemed good.

I guess the last remaining step was to replace the ABS/VDC module in the engine bay. I knew it had to be this module as the main ECU was talking properly to the ABS/VDC unit (via canbus) and no other errors were present. So I went to the local pick-n-pull and grabbed the ABS/VDC module for $45. Before bothering to remove all the hard brake lines into the old module, I simply plugged the cable harness into the new junkyard unit. Well, the error code immediately went away! I cleared out the codes and they never came back.


So there you have it. One cause of wheel speed sensor issues can be a faulty ABS/VDC computer modules. It's easy to do a proper diagnosis without any fancy or expensive tools.
 

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Good day,

I have the same problem on my LegacyGT. Did the ABS module from the scrapyard work or did it have to be coded, also did it come off the exact same year model or not. Any assistance would be great before I spend anymore.

Thanks in advance
 

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Registered
'08 3.0R Limited Sedan; '09 Outback 3.0R
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152 Posts
Discussion Starter #3
Good day,

I have the same problem on my LegacyGT. Did the ABS module from the scrapyard work or did it have to be coded, also did it come off the exact same year model or not. Any assistance would be great before I spend anymore.

Thanks in advance
The ABS module did work. It did not need to be coded...you just plug it in. I'm not sure on the years and interchangability. Comparing part #s is a safe bet.

I trust you did a thorough diagnosis that led to the ABS module rather than a speed sensor?
 

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I recently diagnosed a CEL P0500 Vehicle Speed Sensor issue, and the root cause wasn't the typical damaged ABS wheel sensor. I learned a lot in the process, and I wanted to share it for the next DIY'er that might run into this.

Vehicle: 2006 Tribeca with 247,000 miles. The motor, tranny, and accessories are nearly identical to any of the H6 Outbacks and Legacys.
Symptom: CEL, cruise, along with ABS/brake dash lights. The dash also says "Err SS" which means Error Speed Sensor. The car runs in a failsafe mode where the radiator fans are always on. Vehicle is not in drivable state due to other issues so there was no information on overall drivability.
Check Engine code: P0500 Vehicle Speed Sensor

A few important things I learned:

  • You can read check engine light codes on the Tribeca using the 06-09 Legacy/Outback method described here: 05, 06-09: How To Read Diagnostic Trouble Codes (DTCs)
  • On Subaru's, the P0500 code does not refer to the Vehicle Speed Sensors located in the transmission. The P0500 code actually refers to part of the ABS/VDC system, and you need to retrieve secondary cruise control codes to get more info.
    • However, you cannot read C** codes using the method from the previous bullet as the engine needs to be running for the ABS/VDC module to be responsive. When you use the method above and switch to the C** codes, you will simply see the C---- blinking indefinitely. Not helpful!
  • The simplest way to read the C**** codes (cruise control codes) is to use FreeSSM and a Vag-com ODB2 cable.
    • You can get a cloned vag-com cable on Ebay for $8 shipped. Look for "VAG-COM KKL 409.1 OBD2"
    • With the engine running, click the "Cruise Control" tab in the engine diagnostics of FreeSSM.
    • If you use FreeSSM to look at the Cruise Control codes with the car "on" but without the motor "running", it will display only C0043, which is a bogus code. It's the "cancel code" for when the ABS/VDC module isn't responsive. It means nothing so ignore it.
So anyways, using FreeSSM with the vehicle's motor running I was able to pull C0023. I found a list of ABS/VDC C**** trouble codes somewhere on the net. I attached it here for reference:


This code pointed to the front left (drivers side) ABS wheel speed sensor. Great! That seemed like a simple fix. I decided to take a look at the speed sensor and the condition of the wiring. As I pulled the sensor out of the hub, I noticed it was all chewed up and missing chunks. The damage on the sensor was caused by the magnetic tone encoder ring on the back of the hub assembly.




Well that seemed like an obvious root cause. I ordered a new hub assembly and speed sensor, and I installed them. WRONG. It didn't fix it! I made a rookie mistake on not properly diagnosing the issue and throwing parts at it!

At this point, I found the FSM section on diagnosing Code 0023. It had me test the voltage going to the speed sensor (+12V one pin, GND on the other pin). I ohm'ed out the wiring through the various connectors on their way to the ABS/VDC module. All seemed good.
Great Post! Thank you this got me started, and helped greatly on my P0500 problem.

2007 Tribeca, 195K miles, P0500 and all the lights on all of the sudden. Traction control, Cruise control, even the high beams stopped working which is weird.

I used my Autel scanner to scan the ABS system which gave left Front ABS Sensor Circuit Open. So, I ordered up a new sensor and had trouble getting the old sensor out as the bottom was seemingly stuck and pulled out leaving the outside of the flat part of the sensor stuck in the hole.

While trying to get that out, rotating the brake rotor and looking down the sensor hole, I noticed that there was a piece of metal turning with the axle that was closing up the gap for the sensor for about 1/3 of the revolution. This turned out to be the dust shield on the axle. Somehow, by rusting out, the end of the cv axle was pushing the circular dust shield toward the wheel bearing, pinching and thereby destroying the ABS sensor.

Next was to remove the Axle! Be careful how you do this. There is a video on Youtube that I watched where a guy at a shop changes both front Axles on a 2013 Tribeca in 15 minutes. He does this by removing the tire rod end and ball joint by unbolting the Tie Rod end and removing the pinch bolt from the ball joint, hits both housings with a 3 lb hammer and they drop right out. If you try this you will find that the cotter pin in the tie rod castle nut will be seized and you will need to cut off the ends, spin the nut over it and then drill it out. Then the bad news, the pinch bolt is known to break off in the steering knuckle more than half the time, then you will need a steering knuckle if you ever want to remove the ball joint. This approach is tempting due to not needing to remove the Camber bolt and possibly mess up your alignment. IT IS NOT WORTH IT!!!

Instead, watch the excellent video by A1Autoparts on how to do the Axle. You mark the position of the bolt and the knuckle in the shock bracket with a paint marker, remove the two bolts holding the knuckle to the shock, rotate the knuckle down which makes enough room to clear the axel from the hub. You can leave the Brake and Rotor on so it is "just " two bolts. Mine were some of the toughest to break nuts I have run into. Be sure to remove the nuts, do not try to turn the bolts. I needed a breaker bar and a 24 inch pipe a day of soaking with PB Blaser and nabbed to clean shear a wobble extension in the process.

With the Axle out it was easy to see that the dust shield, a little ring that must be designed to keep crud off the ABS sensor was pinching in on the ABS sensor and was the problem. New axle and speed sensor from Rock and I was good to go. Measured speed from speed sensors with the scanner, all good, cleared the P500 code and all is good. $36 for the sensor, $49 for the Axle. Finding the problem - priceless.

Thank you again for the ideas.

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