1994 944T 86K

The ABS light is on and the self diagnostics indicate a 152 error which is "right front wheel sensor: open circuit or short-circuit to battery voltage".

Front sensors should show 900-2,200 ohms according to the FAQ's. This sensor at the connector lead shows a resistance of 24.5M. I am not familiar with taking resistance readings with this meter. If that is 2,450 ohms it is a bit over specs and I am assuming that is why the light is on. Clearing the code gives me a 1-1-1 until I turn on the key for the first time which illuminates the ABS light once again.

I guess I am just looking for a nod from someone that if those numbers are correct the next logical step would be to order a new front sensor.

Anyone able to supply the part number for that sensor?

The FAQ's state that removing a used sensor usually results in breaking the plastic portion of the sensor. I can attest to that from a trip to the pick and pull this weekend. Even after wire brushing and soaking with penetrant the two sensors I came across broke when I tried to drive them out. The problem is the tone ring. With the tone ring in place straight on access to the shoulder of the sensor is blocked. Otherwise a socket of the correct diameter might fit inside the housing the sensor is fitted to and catch the shoulder of the sensor (metal) and it would not stress the plastic when driving it out.

Of course you would have to be prepared to remove the tone ring which would require a socket of the correct size (large) for the hub nut as well as a very long breaker bar and/or pipe- those nuts are TIGHT!

Recap on questions:

Agreement that I need a replacement sensor?
Can anyone suppy the part number?

Thanks, Randy

I have the luxury of this car currently not being licensed or insured so time was on my side.

I soaked both sides of the sensor with Kroil for two weeks and set up good vibes with a hammer hoping to gain an advantage in removing the old sensor. However, the O rings on both ends prevented any migration to where it was needed.

As trichard suggested it was a laborious endeavor involving driving the center out the back side, and doing some drilling to remove the coil. I ground down a hack saw blade to cut the plastic that remained at the back of the sensor opening.

At that point it was the metal sleeve that remained fast to the interior of the opening. A very small (sharp) cold chisel and a punch cut and peeled the sleeve loose.

Due to corrosion the interior of the opening was to small to accept the new sensor. A dremel with a stone cleaned that up.

I purchased a Bosch sensor. It came equipped with the O ring that seals up the back side of the opening, but the one on the tone ring end was absent. Luckily I had saved the O rings from trying to remove sensors at the Pick and Pull. Otherwise I would not have been able to finish today. It might have been a bit of a wait for one of those.

Edit: I failed to mention that I did not remove the hub to do this. That would have made it somewhat easier as the tone ring would have been out of the way. It was Sunday and the person who I borrow the large socket for the hub nut was not at his business.

Randy

Dear rstarkie,

Hope you're well. The ABS Sensor (front wheel, right or left) is Part #3515092. At a Volvo dealer, MSRP is about $175.

Corrosion can boost resistance. You might want to clean the connector. If nothing changes, then I'd replace.

A penetrating oil might ease sensor removal.

Hope this helps.

Yours faithfully,

Spook

Hi Spook,

Thanks for the part number. Searching the number online I did find a supplier of a Bosch replacement for $75 so it looks like I will be order one soon.

Randy

removing abs sensors is a matter of luck. some come out with no drama whiles others are so corroded in the hole they need to be drilled out using progressivly larger drill bits.

if yours won't budge expect to spend a bit of time and lot of hassle removing it.

that said set your meter ohm setting to the first setting above 2500ohms and take a reading.

even if it comes within specs you might have a lot rust attached to the magnetic sensor end rendering the sensor useless.

remove caliper bolts and hang out of the way line still attached, remove rotor and then clean the sensor end well.

what will happen if it jammed in the hole is the guts of the sensor will come out without too much agro but the metal sensor casing will be essentially fused to the knee arm hole wall. this is where the fun begins

if the sensor was installed with lots of grease or anti seize coating around the casing wall they come out much easier

Thanks for your response. I had already removed the caliper and disk, but cleaning things up did not produce any changes in the resistance.

I started soaking the sensor as soon as I realized it would probably have to be replaced so hopefully that will help.

Randy