Pinout Box (for troubleshooting ABS System)

[Guest Kitskaboodle]

I just purchased a J-35582 Pinout Box (from Kent-Moore)

to aid in troubleshooting my brake issues.

Just wondering who else has one and if it has really helped you

regarding resistance checking your ABS wiring?

I need all the troubleshooting help I can get.

Walt...how are your electrical troubleshooting skills?

Kit

[padgett]

Wouldn't mind adding one to my collection but have always been able to use the trunk connector and a DVM to troubleshoot.

[DAVES89]

I have one and yes it helps. Takes all the guess work out. You plug the unit in and just use your test light or DVM [can't remember which] to see what sensors work.

[Guest Mc_Reatta]

It helps troubleshooting but as Padgett points out is not mandatory to do so.

What are you trying to figure out?

Hope you have a DVM to go with it.

Also be aware that there are some possible errors in the FSM in this area confusing left side and right side information in either the EBCM or in it's output via the flashing of the the brake light during diagnostics.

We may use you as the Guinea pig to figure out if the disconnect is in the breakout box, diagnostic display, or just the FSM

[wws944]

I was over at Kits place a few weeks ago, and we were getting codes that seem to point to the front left ABS sensor - even though he has replaced all the ABS sensors. Symptom is that the ABS light comes on at about 10 mph and never goes out. (Kit has replaced the EBCM a couple times and the whole Teves unit as well, to no avail.)

We have fixed a couple of other things in the meantime, including using my spare IPC - because his was intermittent, and replacing the missing ALDL connector cover so that the proper jumper is in place.

DVM availability is not a problem.

Edited October 7, 2010 by wws944
typo (see edit history)

[padgett]

That indicates continuity during self test but an intermittant (possibly) at speed. Once the ABS light is on, it will not go off until the key is cycled even if fault is momentary. Triggering over 10 mph sounds like a wheel speed sensor missmatch. Does it trigger in a straight line, when hits a bump, or when turning ?

I have heard of a lot of dirt packed in the teeth (front) triggering a fault. Might also check the clearance between the teeth and the sensor at the front, spec is supposed to be .020".

This might be a good time to open sensors and see which codes are set for each. I have seen a RWSS fault (passenger side ?) be indicated by the driver's side. And a Left (LWSS) code caused by a rear. Have never figured out which way they are facing for right and left. Do know the ABS works properly (L/R/Rr) in my cars.

[wws944]

... Does it trigger in a straight line, when hits a bump, or when turning ?

Straight line - no bumps.

FWIW, Kits pedal is a bit low compared to my car too. We are thinking this may be a bleeding issue. Shouldn't affect the ABS, should it?

[padgett]

I would not think so but "never say never". Key here is the 10 mph. I *think* that is about where the ABS "arms" itself. It apparently is passing the static (continuity) test but failing the dynamic one.

At this point a pinout box particularly inside the passenger compartment and a 12v O'scope would be very handy (might see in a DVM). Suspect the signal from one sensor is much lower than the others (infant mortality ?).

Conductive dirt in the teeth or a sensor spaced too far from the teeth would do it. Visual inspection of the front teeth/sensor (rear is encased) is where I would start.

[wws944]

Unfortunately, my scope is an 'old school' Tektronix and would be hard to fit in a Reatta...

Good ideas on checking the sensor teeth. It would make a lot of sense, because the problem does not feel 'intermittent'.

[Guest Kitskaboodle]

As Walt had mentioned the ABS light comes on when you get past 12 mph. And then it never goes off as long as you are driving.

Also, as he had mentioned 2 of the 3 ABS codes I have indicate an issue with the

front left wheel sensor. Funny thing is, I replaced both wheel sensors with factory AC-Delco ones. (less than 2K miles on them)

Padgett....PLEASE explain about wheel sensor adjustment.

I though they were not adjustable since they simply go into the hole with

one simple screw. Also, is the ring adjustable??

This weekend I'm going to pull the driver's side front wheel off and take a look see to see if the ring has dirt in it/broken teeth, etc...

Oh, and regarding the lower than usual brake pedal feel....I dont think that is a contributing factor in my ABS light issue since this ABS issue has been there since I bought this car years ago. The Teves unit has been replaced twice but I have always had the exact same issue!

Kit

Edited October 7, 2010 by Kitskaboodle (see edit history)

[padgett]

Least expensive I've seen in a quick look is $140 inc shipping for a USB o'scope that would work nicely with a NetBook though for a few sheikels more, this one looks considerably more powerful.

BTW my 1970's vintage Tek 922 works fine with a jump box/inverter.

[padgett]

OK, the front sensors do mount with one screw however the screw is into an adjustable bracket (two bolts with 10mm heads on the backside of the hub AFAIR).

I also recal being able to get a bent .020 feeler between the toothed hub and the sensor but the wheel must be removed first.

Codes seem more in the way of guidelines than biblical, not sure which side they mean by "right" and "left". Are you able to read codes ?

At one point I thought 7x was current and 3x was history but never got very far & documentation is no real help.

One project I have planned for years is to hook up an EBCM and sensors, remove one at a time, and see what code sets.

[Guest Kitskaboodle]

.020 huh?

Is there a range/tolerance for the wheel sensor to ring gap

or should I shoot exactly for .020?

My car was throwing 3 codes but maybe a 4th but am not sure.

At least two of the codes are pointing a finger at the left front

wheel sensor.

By the way, when I installed the new wheel sensors I just bolted

them in and plugged them into the harness. That's all i did.

Will need to jack up car, take wheel off and take a close look.

Thank you sir for your input.

Kit

[padgett]

Did you get 31, 41, & 75 ? The only definitive way I've found is to remove the EBCM connector in the trunk and check resistances but sounds like it fails when moving only which points to a mismatch. May be able to see on a DVM but would need the breakout box to see while moving.

Might just unplug the driver's side and see what code you get. Think it is different than documented (36/76 AFAIR)

[wws944]

Some interesting background information on the Teves Mk II system: Ford Thunderbird - ABS Anti-Lock Brake System

[DAVES89]

Don't ask me how I know, but did you make sure you have the EBCM plugged in correctly?

[wws944]

More interesting background info on the Teves Mk II from an Alfa forum: Debugging the Milano/75 ABS System

Dave: Kit claims no bent pins.

[Guest Kitskaboodle]

OK....pulled some front wheel sensors off an 88 yesterday.

Also pulled the wheel sensor brackets Padgett was talking about.

So....after noticing the oversize bracket bolt holes

(it is obvious when you hold the 10mm bolts up to them)

they MUST be adjustable EVEN THOUGH the FSM says they're not!

Stay tuned....Kit

[Guest Kitskaboodle]

OK...I pulled the driver's side front wheel off to take a look:

1) Observation# 1

There is NO adjustability on the wheel sensors for 1990 models.

They simply bolt into the knuckle and that's it. The FSM was correct!

On the 88 I visited yesterday there is a seperate bracket that the

wheel sensors bolt into as Padgett had mentioned. Not sure why they

took away the adjustability for the wheel sensors....

2) Observation# 2

The wheel sensor to ring gap is a little above .040.

Well, at least on my driver's side front that is.

FSM doesnt give this gap so I will assume it's ok.

3) Observation #3

The wheel sensor RING does have 2-3 teeth that have some small damage

near the edges. It looks like someone took a screwdriver and tried to pry on the ring at the edges. The edges of the teeth were pushed up a tiny bit because of this. I took a Moto-Tool and sanded them down flat. After doing this these 3 teeth no longer are the FULL WIDTH compared to the other teeth.

4 Observation #4

Went for a short drive and the ABS light came on exactly at 13mph as usual.

So.......per Padgett's request I disconnected the driver's side wheel sensor and now I notice the ABS light is on all the time.

Next on the agenda is to read the codes again when I have time.

Questions:

A) Is the ABS system disabled by disconnecting one wheel sensor?

The FSM says the C.V. axle must be replaced when replacing the wheel sensor ring. If this is true, do new or rebuilt axles come with the ring already installed? Or, do you have to buy the ring seperately?

Thanks, Kit

[Guest Kitskaboodle]

Anyone?

Padgett?

I still need answers to my questions.....

Kit

[Ronnie]

Questions:

A) Is the ABS system disabled by disconnecting one wheel sensor?

The FSM says the C.V. axle must be replaced when replacing the wheel sensor ring. If this is true, do new or rebuilt axles come with the ring already installed? Or, do you have to buy the ring seperately?

Thanks, Kit

Yes, disconnecting one wheel sensor would set a code and turn on the yellow ABS light. Anytime the yellow ABS light is on the ABS system is disabled.

Yes, the ring is on the axle (half shaft). The correct rebuilt axle for a Reatta will have the ring on it.

Don't know if the ring can be purchased separately. Rule out other problems before buying a rebuilt axle. Not likely your problem.

[padgett]

Agree. BTW ABS light will stay on even if you reconnect until you turn the ignition off - it latches. Codes will reset when you drive above 38 mph after reading AFAIR.

[Guest Kitskaboodle]

OK...I spent a 1/2 hour going through the diagnostics using the climate control. This is what I came up with but am unsure how to interpret it.

After first entering diagnostic mode I got this:

"No E code"

"No B code"

"061c"

After running the individual BCM input parameters I got these "LOW" inputs:

88, 78,77,76,71,25,22,05,03,02

Are all these numbers supposed to be high or do I need to find out what they are and test each sensor/part that these numbers represent?

Also, if I am reading the 1st code correctly that code is low fluid level?

Is this correct?

Where do I go from here?

Thanks, Kit

[padgett]

Sorry ABS codes are read by jumpering the ALDL connector and counting the flashes of the yellow ABS light. See section 5E in the FSM for a complete description. 88 is A-G, 89-90 is A-H.

[Guest Kitskaboodle]

OK...spent some time tonight reading the codes (the CORRECT way sir)

5 codes total and this is in their exact order as I read them:

Code 21 (main valve)

Code 12 (EBCM problem)

Code 31 (Left front wheel sensor)

Code 45 (Missing wheel speed sensor signals)

Code 75 (Left front wheel speed sensor)

As a reminder I now have an official GM pinout box to measure resistances

at the EBCM (trunk) connector.

Where do I go from here?

Kit

[padgett]

Odds are that all stem from one sensor. Now try measuring the restances for all four at the EBCM connector (breakout box is usefull for this.

[Guest Kitskaboodle]

OK...I did a tiny bit more this evening. (with my new GM Pinout box)

I focused on just two of the codes tonight: Code 31 & 75 (left front wheel sensor) (sorry Padgett, didnt have the time to check all the other wheel sensor voltages)

1st test: Measurement between pin 5 & 23 is 1.07K ohms. (within acceptable range according to FSM)

2nd test: No continuity between pins 1 & 23 (left front wheel sensor disconnected)

3rd test: No continuity between pins 1 & 5. (left front wheel sensor disconnected)

FSM says to then go to Wheel Sensor Test F. (Need to raise wheel and have assistant spin wheel at 12 mph while checking sensor voltage) I will do this test in the next day or two.

Regarding the actual left wheel sensor the FSM said to check the continuity

between the pins and ground. I am getting nothing on my Ohmmeter though.

Am I doing something wrong??

Thanks, Kit

[padgett]

Don't think the sensors should be grounded anywhere, is two signal wires not one and ground.

Need to check all four sensors because I *think* the chart is wrong as to *which* sensor has failed.

[Guest Kitskaboodle]

OK..per your request Padgett I checked the resistances of all 4 wheel sensors at the ECBM/trunk.

Here they are: (done with GM Pinout box)

Left front wheel sensor : 1076 ohms

Right front wheel sensor: 1057 ohms

Left rear wheel sensor: 1100 ohms

Right rear wheel sensor: 1100 ohms

(FSM says 800-1400 is acceptable range)

Seems like these numbers are pretty closely matched in ohm value so they really shouldnt be triggering the ABS light to come on.

You sure it's not time to raise the left front wheel and have an assistant spin the wheel at 12 mph and take a reading??

OR..where do I go from here??

[wws944]

Sounds like it is time to try lifting the wheels and spinning them. All of them.

Padgett: You seem to be saying that the ABS codes may be pointing to the wrong wheel. Does this mean the Reatta wiring is wrong? Or perhaps the firmware has a bug? Did they ever issue a TSB on it? Seems strange GM would let such a problem go for three model years and not get it fixed. But then, we are talking about GM...

[padgett]

I do not know. The blue car acted that way and turned out to be a frayed cable that shorted when I'd hit a bump. Cycle the ignition while moving asnd it would go out until the next bump. Spent a lot of time troubleshooting the passenger side per the codes but turned out to be the driver's side. Bad cable was obvious when I removed it.

[Guest Kitskaboodle]

OK....next step today was to do Test "F".

I couldnt get an assistant to spin the wheel fast enough to even get a reading so I ended up driving the car down the road in order to to get readings.

(Pinout box hooked up and ran it through the trap door that goes through to the trunk)

I'm no ohmmeter expert so I hope these measurements are correct. I set the meter for AC volts (it is auto-ranging) and this is what the ohmmeter displayed for all 4 wheel sensors while checking the pinout numbers according to the FSM:

Note: All readings were taken at a steady 16 mph, ok?

Left front sensor: .002 (steady reading)

Right front sensor: .001 (steady reading)

Left rear sensor: .580 (avg.)

Right rear sensor: .330 (avg.)

Notice the notations "steady reading" and "avg".

This is because as I varied the cars speed the voltages changed, well at least

for the rear sensors. The fronts seemed to stay at a steady voltage despite speed changes. (not sure why)

SO......the front sensor readings seem awfully low dont they?

Also, can someone please verify the actual voltages displayed here?

For example, .001 is 100 millivolts? Or is it 10? (I'm not a math expert either)

Thanks, Kit

[padgett]

.1v is 100 millivolts, .01v is 10, .001v is 1. Most DVMs will be 2-4mv off unless zeroed. Sounds like no signal from the front. Have to ask: are there teeth on the axle below the front sensors ?

Is that DC or AC voltage you read ?

[wws944]

Is it possible to turn off the auto-ranging? Hard to say how the readings compare unless you also recorded the units that were displayed at the time of the measurement.

[Guest Kitskaboodle]

Padgett, the switch on the Multimeter was set to AC volts, not DC.

As I mentioned, the drivers side front ring gear had two to three teeth

that were slightly gouged at the edges but I filed them down.

Funny thing is...I have not even looked at the other 3 ring gears.

Perhaps I should check at least the right front, huh?

Anyways, here is a pic of the multimeter I am using.

It's an Innova and I got it at Wally-Mart for around $30-33 bucks.

Turn off the auto-ranging?? I dont think it can do that but I'm not sure.

Walt......why dont you come over next week? I'm having a Reatta trouble-shooting party and you're invited!

Kit

[padgett]

Well I have flown to SF for dinner before but that was in the glory daze of the dot coms. Don't miss four hour flights even in first, do everything from home now.

Bottom line: if getting .001v when moving from both fronts, something is rong & is going to take an end to end check to figure out what.

Just for S&G, what are the readings (may need to use an ohms scale, not certain) if the EBCM is disconnected from the sensors ? I am wondering about an internal problem. Is lots easier when you can just swap things.

Edited October 25, 2010 by padgett (see edit history)

[Guest Kitskaboodle]

After checking the resistance value of the wheel sensors the very next two tests (in the FSM) is to unplug the wheel sensor connector and then check two different pinout points and verify if there is any continuity. There was no continuity so the book then says to go to test "F". As an FYI I did not do this test to the other wheel sensors.

Where do I go from here?

Kit

[padgett]

Which "F" chart and which pins have no continuity ?

[wws944]

...

Anyways, here is a pic of the multimeter I am using.

It's an Innova and I got it at Wally-Mart for around $30-33 bucks.

Turn off the auto-ranging?? I dont think it can do that but I'm not sure.

Is this it: The Equus Innova 3320 digital multimeter

Looks like the lowest range is a 2 volt scale. So all the readings are probably in millivolts.

Walt......why dont you come over next week? I'm having a Reatta trouble-shooting party and you're invited!

Not sure. Would be nice to get the daemons exorcised by Halloween though...

[Guest Mc_Reatta]

Looks like next step is 2 working front speed sensors.

Make sure the fluted metal rings are in place on the axle, and have a clear shot at the sensors.

Didn't sound like you had any adjustments to the gap between the rings and the sensor body to adjust the gap.

Would think if the sensor had proper resistance (which it does) it would work, as long as the actuator was present and in range, but I guess not.