2000 S70 ABS Light Issue

Obg8 · Post by **Obg8** » 07 Jan 2024, 07:02

Hello, long time lurker first time poster.

I have a 2000 S70 GLT SE. My ABS light and Traction control light came on a few weeks ago. The car is not my daily driver but I’ve been trying to get to the bottom of the issue for a few weeks in my spare time.

Originally I googled and read topics here about the ABS Module being a likely culprit. I removed the module from the car and found it had previously been repaired by BBA Remanufacturing at some point before I owned the car. They are permanently closed so that is no help.

I read that once they solder the module it’s usually fine for the rest of its life so I didn’t open it at that time and put it back in the car. I borrowed a scan tool from a friend and found that the left front wheel sensor was throwing a code in the ABS Unit. I was also getting a P1550 code from my cheap scan tool. Which is a speed signal error.

I decided to replace the left front ABS speed sensor because I was out of ideas. I installed it and nothing changed. I am able to see each wheels reported velocity and found the left front not responding while all the others work. I spoke to the eBay dealer and they sent me another sensor for free so I tried that, still no signal from that wheel. I checked continuity of these sensors and found them to be 500 ohms which makes me wonder if both sensors are garbage as I’ve read on here that they should be around 1000-1500ish ohms.

I was wondering if anyone had a suggestion on where to look next. Should I get an oem Volvo sensor? Is it possible the tone ring is bad or the gap is improper? Do I need to open the ABS module and possibly solder it again? Or is my ABS module just shot.

I also checked continuity from the wiring harness for the whee sensor back to the module and found no issues there.

Thank you.

Post by **scot850** » 07 Jan 2024, 08:34

What brand is the sensor? ATE is the OEM, so if You can find one of those then I would suggest that or OE Volvo.

Just because a unit has been re-soldered, it does not mean it is bulletproof. Mine was re-built by Xemodex, and occasionally I get a random code. As it was replaced by the previous owner the warranty is void. If I need another I will go to Matty at Mid-West.

What I suggest to others is to jam a wedge between the wires and the ABS module and see if that makes a difference. It is a temp measure to force the contacts together.

Neil.

Obg8 · Post by **Obg8** » 07 Jan 2024, 08:53

scot850 wrote: ↑07 Jan 2024, 08:34 What brand is the sensor? ATE is the OEM, so if You can find one of those then I would suggest that or OE Volvo.

Just because a unit has been re-soldered, it does not mean it is bulletproof. Mine was re-built by Xemodex, and occasionally I get a random code. As it was replaced by the precious owner the warranty is void. If I need another I will go to Matty at Mid-West.

What I suggest to others is to jam a wedge between the wires and the ABS module and see if that makes a difference. It is a temp measure to force the contacts together.

Neil.

I’m not sure the brand, unbranded maybe? Here is the link to what I bought if it helps.

https://www.ebay.com/itm/174950068855?h ... BM-I7LyZxj

Sorry the link is super long, on mobile so not sure how to shorten it.

I will try to wedge the wires to see if it’s a connection issue, I also thought about connecting some leads to the sensor and check voltage while moving to see if the sensor is even producing any signal.

I’m just not sold it’s the wheel sensor at all to begin with, as from reading many ABS threads on here it seems the module is usually the root cause.

Thank you.

Post by **MoVolvos** » 07 Jan 2024, 11:30

Obg8 wrote: ↑07 Jan 2024, 07:02 Hello, long time lurker first time poster.

I have a 2000 S70 GLT SE. My ABS light and Traction control light came on a few weeks ago. The car is not my daily driver but I’ve been trying to get to the bottom of the issue for a few weeks in my spare time.

Originally I googled and read topics here about the ABS Module being a likely culprit. I removed the module from the car and found it had previously been repaired by BBA Remanufacturing at some point before I owned the car. They are permanently closed so that is no help.

I read that once they solder the module it’s usually fine for the rest of its life so I didn’t open it at that time and put it back in the car. I borrowed a scan tool from a friend and found that the left front wheel sensor was throwing a code in the ABS Unit. I was also getting a P1550 code from my cheap scan tool. Which is a speed signal error.

I decided to replace the left front ABS speed sensor because I was out of ideas. I installed it and nothing changed. I am able to see each wheels reported velocity and found the left front not responding while all the others work. I spoke to the eBay dealer and they sent me another sensor for free so I tried that, still no signal from that wheel. I checked continuity of these sensors and found them to be 500 ohms which makes me wonder if both sensors are garbage as I’ve read on here that they should be around 1000-1500ish ohms.

I was wondering if anyone had a suggestion on where to look next. Should I get an oem Volvo sensor? Is it possible the tone ring is bad or the gap is improper? Do I need to open the ABS module and possibly solder it again? Or is my ABS module just shot.

I also checked continuity from the wiring harness for the whee sensor back to the module and found no issues there.

Thank you.

.
When I purchased the 98 S70 T5 back in 2012, I used the wedge method on the ABS plug of the Module to test and it temp alleviated the issue. I later took it apart and repaired it.

Fast forward to the 00 S70 SE Base, code kept showing ABS sensor and other issues. Took it apart and soldered it and have not had any problems since. You can get all sorts of ABS and dash issues with the module.
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viewtopic.php?p=619939&hilit=4mm+socket ... op#p619939
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Post by **scot850** » 07 Jan 2024, 12:42

Did you test the resistance on the original ABS sensor to see if it was in the same range as the others on the car? If it is good I would put it back unless there are other issues going on.

One other thing to do is to check the condition of the reluctor ring on the end of the axle. They can crack with age, get rusty to the point the sensor cannot see the teeth to measure correctly or just get dirty and filled with crap. I think it may have been foggydogg and duke1 who have changed the rings recently due to issues.

Neil.

Obg8 · Post by **Obg8** » 07 Jan 2024, 16:14

scot850 wrote: ↑07 Jan 2024, 12:42 Did you test the resistance on the original ABS sensor to see if it was in the same range as the others on the car? If it is good I would put it back unless there are other issues going on.

One other thing to do is to check the condition of the reluctor ring on the end of the axle. They can crack with age, get rusty to the point the sensor cannot see the teeth to measure correctly or just get dirty and filled with crap. I think it may have been foggydogg and duke1 who have changed the rings recently due to issues.

Neil.

Unfortunately I tossed the old sensor weeks ago. I will look at the tone ring next time I work on the car, I'm not sure if I'll be able to distinguish between a good or bad ring though. I do want to connect my multimeter to the sensor while the car is moving and see if the cheap eBay sensors are producing any signal, I guess that will tell me if the issue is related to the ring/sensor and not the module itself.

If anyone else has any other suggestions feel free to continue to post them, my next step after checking the voltage, if it is producing some signal would be to open the module itself and check all the solder joints I suppose.

Thank you all again.

Post by **scot850** » 07 Jan 2024, 17:04

This may help on tone rings:

: Front axles; Interior color and RH drive axle 006.JPG (258.08 KiB) Viewed 603 times

The upper of the 2 axles is almost like new condition. The lower one is a little dirty but still in good condition.

If your tone ring (you can see it through the sensor hole more easily) is excessively rusty/crusty, or has a bunch of dirt in there, then it can cause a tooth to be missed which will through an ABS sensor code. The reluctor ring is a little tricky to replace, but this gives you an idea:

https://www.google.com/search?q=Swappin ... TL3uo,st:0

The rings can also crack if rust builds up on the shaft it can cause the steel to swell and cause the ring to split.

Neil.

Post by **abscate** » 07 Jan 2024, 17:39

The money saved on eBay parts is lost three-fold in repeated labor and diagnosis of same bad parts.

Get ATE sensors from a known distributor of non-counterfeit parts, four letter auctions and jungles do not satisfy this criteria

Post by **MoVolvos** » 07 Jan 2024, 18:37

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I found a photo of the ABS plug from perhaps the first documented ABS Module repair on MVS. I've added an arrow to where you can wedge a washer, piece of plastic or wood shim for construction to test the ABS. It's a test for the voltage in pin area going into the board and not other areas, which may have cold joints also.
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viewtopic.php?t=12651
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: ABS.png (1.49 MiB) Viewed 596 times

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Post by **Matty Moo** » 08 Jan 2024, 06:08

Abs-0011 Lf wheel sensor, faulty signal is usually the first code to come up with a faulty module on a 99-2000. That's provided there isn't an actual physical issue at that wheel.

Oem speed sensors rarely go bad but the wire going to them can from mileage and age. Aftermarket speed sensors seem 50/50 if they work or not, I'd go with a used oem sensor over a new aftermarket sensor.