04 S

Lights came on a few weeks ago--went off once (all by themselves), but came back the next day. Board lore indicates wheel speed sensor--ordered one up ($39!), and then got the codes read (actually, bought a reader )

5E19 CAN data from DME/DDE
5E1F Steering-angle sensor, identification
5E16 CAN Connection to instrument
5E5C DDS-button fault
5DC0 Wheel-speed sensor, rear right.

Ha, says I. I'll replace the right rear sensor...

Ha. That didn't fix the problem.

So, who's got a primer on these systems and their interactions?

Thanks--

BobH

 

Hmmm.

Nobody, eh?

OK, then> Is what I've found out (to date) about these systems, as well as what I'm thinking:

The CAN bus is a twisted pair that provides two-way *parallel* communication between the following modules: ABS/DSC, Engine Control Module, IKE (instrument cluster), and the steering angle sensor. I've seen (on the 'net, you know) that the electro-hydraulic steering module is also connected to the CAN bus, but my Bentley doesn't show that. (page ELE-66, for those following along).

The D-Bus is a completely separate bus that connects all of these modules to the Diagnostic Connector port. (which I assume(assume) is the OBDII port).

A 'failure' in a wheel speed sensor should result in the tire pressure light coming on (as that system relies on RPM of the tire), and the ABS system light coming on (same reason), and the DSC coming on (DSC needs ABS to work). That all makes pretty good sense.

Of my codes, only 5DC0 (wheel-speed sensor, Rear right) seems to be directly related the 'trifecta' of lights. I've replaced the RR wheel speed sensor, and the problem persists.

As an aside, and FWIW, My ABS system still seems as if it partially works--On wet pavement, I can hear and feel, through the pedal, the system engaging--I suspect that it's only working on one axle, though.

The code 5E5C (DDS-button fault) is just weird.

The other codes--
5E19 (CAN data from DME/DDE)
5E16 (CAN Connection to instrument)
5E1F (Steering-angle sensor, identification)
seem to indicate that the ABS/DSC module isn't communicating with the engine, instrument panel, or steering angle sensor. Does it do this when it (the ABS module) faults out (ABS/DSC lights on=stop talking to other modules), or does this indicate a failure in the CAN bus? Wouldn't a *real* CAN bus failure also result in a dead instrument cluster?

My scanner seems to be able to communicate with the engine and abs/dsc--but that communication is all through the D-bus, isn't it?

What would the symptoms of a CAN bus failure be?

Would an ABS/DSC module failure result in this kind of behavior?

Can the wheel speed sensors be checked with a multi-meter? It looks easy enough to pull the DSC/ABS connector and check (appropriate)pin to (appropriate)pin---well, easier than going around to each wheel and doing it--with the added benefit of checking all of the wires out to the sensors, too.

If I disconnect the battery, what should the CAN bus resistance be--wire to wire, wire to ground? or is that going to be a bad idea?

Any thoughts/refutations/corrections/amendments welcome-

BobH

 

I had a lose fuse which resulted in the behavior of an ABS module failure.

https://www.northamericanmotoring.co...o-no-tach.html

Basically the most noticeable difference is that you would have lost your speedometer and odometer, which I assume you would have posted.

I would say to check your fuses if you haven't already. There are 3 fuses for the ABS module (1 in the panel under the steering wheel and 2 in the Engine compartment..bentley manual can tell you which). Also you could try leaving the car battery unplugged for a while to see if that resets anything.

You could also make sure the harness at the ABS module is properly seated (it's hard to get to, so I probably wouldn't pull it out and re-seat it, just push it in a bit). I doubt that is the issue, but it wouldn't hurt.

Unfortunately I can't tell you what codes I had because I didn't have a reader at the time.

You seem to more about this than me, but I'm just trying to give you some ideas. The people that responded to my post suggested electrical and it turned out that they were right.

 

Thanks Cenobia.

Any input..at this point..is appreciated. I'll go fuse checking tomorrow. I've actually pulled the ABS connector off the module, just to check the harness for obvious damage--we do have (mice?) up here that like to live under the hood.

I'm also trying to figure out what all of this stuff--the codes--mean. Even if it's just going to be a single wheel sensor that's bad--and I suppose that it could be that or it's wiring harness--there must be a reason for all of the other codes.

Again--Thanks.

BobH

 

OK, fixed. I got tired of waiting for you guys to fix it for me.

So. I unplugged the wiring harness from the abs module and checked resistance for the wheel sensors.

Pins 42-43=open
Pins 37-36=3.97M
Pins 33-34=6.64M
Pins 46-45=6.74M

Aha, says I. I believe that pins 42-43 must be for the RR wheel speed sensor. Off comes the RR wheel, and I disconnect the (new) wheel speed sensor. I make a teeny little jumper wire and plug it into the harness side of the connector, thereby shorting the twisted pair.

Checking Pins 42-43 indicates that they are still open

Well, heck. So I start pulling the car apart to follow the harness and visually inspect for damage. Starting at the rear, the rear seat bottom comes out, the passenger seat comes out, the interior sill trim comes off--pull up the carpet and start following the wire...from the grommet in the rear, alongside the sill, past the body control module, and up the dash. Pull out the glovebox--and follow the harness through the firewall...Into the engine compartment. Pull the plastic trim piece behind the ABS module out.

No sign of damage.

So, remembering that the ABS/DSC/Tire pressure light went out twice by itself, I set my DVM to continuity (it produces a tone when there's continuity.) Then, starting at the ABS end of the harness I gently twist/jiggle the harness all the way back to the wheel speed sensor end. 5 inches from the end of the harness, after the Brake Pad Sensor/Wheel Speed Sensor split, the Multimeter beeps.

I should have started at that end.

I cut the undamaged tape off of the harness, and there's the break. Solder and shrink wrap. Retape. Re-assemble the car. Turn the key.

Lights are still on.

Use the scanner to clear codes.

Lights are still on.

*swear softly*

Remembering that the brake pad sensor required driving the car to reset, I drive the car.

The lights go out.

_beers_ all around.

I still have no idea why all of those other codes are triggered.

BobH

 

i have these triffecta lights on since yesterday. im wondering where did you buy the speed sensor? thanks.

 

I just received mine today from autosheperd.com. Found them on Amazon search. The sensor was $53 with free shipping. It is a Beck/Arnley piece from Germany. Additionally, I found my sensor problem to be the passenger side front. The wire had gotten into the harmonic balancer and rubbed both wires completely in two. This is a common place from what I have read and it may save you some searching. Just remove the tire and wheel well liner and feel/inspect the wire directly in front of the balancer. More trouble to get to than to fix!

 

thanks for responding and tips for searching the problem. i remember pressure washing the front passenger area 2 weeks ago. water intrusion might have cause the issue. again thanks.

 

rx808

Do you remember which pins go to which wheel.

I'm getting the trifecta lights and pins 46-45 measure way low, only 320k.

I can't get any scanners to pull codes from the ABS.

Thanx!

 

I get the Trifecta of lights, speedo and milage no longer work, when I hit 70 mph. I stop, shut it off, all lights and speedo go back to normal when it starts. If i keep it under 68mph all is good. I just changed the rear wheel hubs and planning a trip to FLA on Sunday from Cape Cod. I ran the car and shook all 4 sensors wires at the whells to see if I would get a reaction, but nothing happen. Any input would be helpful.

 

I would assume the ECU uses one of the pulse sensors for the speedo and odometer, which wheel I do not know.

I found a wiring diagram which pointed my low ohms measurement to the drivers side front wheel.
I unplugged the blue plug, checked the wire for any worn insulation and put it back together.
I couldn't get the sensor out of the hub, I soaked it thoroughly with penetrating oil hoping when the replacement arrives it will come out easier.

What is odd is the light has not come back on since.
Maybe the contacts in the connector weren't making good contact, I don't know....

I guess I'll have a spare when the new on arrives.

In 99500 miles this is the first problem I have had

 

check out the wiring diagram and connector information here @ http://www.pinoynapinoy.us

 

here's the update on my trifecta lights.

i read all sensors with my multimeter and they should read 0 ohms. my rear driver side was the only one that was acting up so i ordered the sensor and replaced it. i drove the car and the lights extinguished as soon as i reach around 5 mph. i found these sensors for $35 plus shipping. if any of you needs sensors pls let me know.

 

I thought wheel speed sensors are only on the front wheels?

 

there's four abs/wheel speed sensors.

 

Hi all,
I have the same issue with my ABS/Tire pressure lights (non DSC) base Mini. I've checked the resistance on all 4 sensors. The rear ones are reading around 21 M, but the front ones are 161 M, each. I am not sure if both front ones could be bad. If I understood correctly, all 4 should read about the same resistance, right?
I'm thinking to buy both front ones and replace them.

 

I would say to check your fuses if you haven't already.

 

Done that. I've checked all fuses and all are good. The warning lights used to turn on when I was turning the steering wheel faster while leaving from stand still... but now they are turning on as soon as I move the car.
I think I'll buy the sensors for front and see if this will fix the issue.

 

oviluca: As I recall (from doing mine)( and getting weird readings) the sensors are polarity sensitive, and will read high one way, and low the other. Are you measuring at the ABS connector?

 

Yeah, I was measuring at the ABS connector. Didn't think it would be polarity sensitive. I will re-measure it tomorrow. Thank you.
Anyway, something is wrong...

 

Measured all sensors and all look good. Fuses are good, tires are at the same pressure. However, I still have the lights come on my dashboard. It doesn't have DSC so there should not be a steering angle sensor. I've tried to reset the tire pressure light and all is good untill I turn harder, like getting out of a parking lot... and then the lights come on again. Driving straight, doesn't trip the lights. Not sure what's going on. I think I have to visit the dealership.... unfortunately.
Any other ideeas? Or places I can check before I go to dealer?

 

Just to double-check: Have you checked the condition of the front right sensor wire itself, as suggested below:

When I "lucked" into my light trifecta, the culprit similarly ended up being a worn sensor wire (though I'd only made it through the sheathing, not all the way through the wire itself!).

 

Yes, both sides look good. They are routed under the frame and I didn't see any friction signs. I even dissasembled the clock spring at the steering wheel thinking it may give some steering positioning input, but I realized it cannot be it, the way is built. Maybe is some recoding to do at the controller.... don't know.
I did schedule an appointment at the dealership for next week, tuesday. Hopefully they can perform a diagnosis at least, just to find what's wrong. I can change the parts if needed. We'll see.

 

Good luck; keep us posted!

 

Well, went to the dealer just to find out that front left sensor is bad. I had the sensor purchased just in case and I've replaced it last night. So far all is working good. No more lights.
So you guys were right, the left front sensor goes bad even if by measuring it, seems ok. Don't understand this, but I'm just happy that the problem is fixed, hopefully for good.
Thanks guys.