P38 new problem with abs and traction fault

[Datatek]

But how do I change the setting for brake switch 2?

See pwood999's post.

 

[pwood999]

@MontyChambers did you do the Nanocom check (not while driving) on the two inputs ? No point in replacing the switch unless you're sure it's broke !!

The RAVE procedure had a missing bit between 7 & 8. It should be:

7. Extend switch plunger fully.
7a. Hold brake pedal down.
8. Fit switch & then release brake pedal.

That way the pedal sets the plunger correctly when you release the pedal.

 

[Datatek]

@MontyChambers did you do the Nanocom check (not while driving) on the two inputs ? No point in replacing the switch unless you're sure it's broke !!

The RAVE procedure had a missing bit between 7 & 8. It should be:

7. Extend switch plunger fully.
7a. Hold brake pedal down.
8. Fit switch & then release brake pedal.

That way the pedal sets the plunger correctly when you release the pedal.

View attachment 341450

Ah good, you have corrected me.

 

[kermit_rr]

If it's already in place then you can pull the plunger out with the pedal down, you don't need to remove it and risk braking it
Pun intended

 

[MontyChambers]

If it's already in place then you can pull the plunger out with the pedal down, you don't need to remove it and risk braking it
Pun intended

Very helpful, tomorrow mornings job, by the way nanocom is running as it should, Hope for clear sky's tomorrow, metaphorically as well as weather-wise!

 

[MontyChambers]

When I remove the switch the Nanocom reads sw 1 closed sw 2 open. When depressing the plunger I can feel it switching halfway and again fully depressed.
When I reattach the switch the reading is both closed when depressed,

Very helpful, tomorrow mornings job, by the way nanocom is running as it should, Hope for clear sky's tomorrow, metaphorically as well as weather-wise!

the brake switch was toast, felt like it was full off grit!
Replacement ordered.

 

[MontyChambers]

I fitted the new brake switch as per RAVE
Readings are:
Close/Close
Close/Open
Open/Open
I must be missing something here?
ABS/TC dash lights still on.
Did I fit the bulb correctly
The dash lights only came on after I fitted new ABS sensors, brake calipers, ball joints, dust shields, and track rod to the front wheels.
The MOT has become a distant dream over mountains of cash!

 

[pwood999]

Check again with Nanocom, but wait a second or two for both to register. Not sure which is sw-1 & sw-2 from RAVE diagram.

Pedal released - Pin 3 open & pin-2 closed.
Pedal pressed - Pin-3 closed & pin-2 open.

There might be a mid point in the switch travel where you get open-open or closed-closed, but only if the switch is not correctly set.

 

[MontyChambers]

The chances of have the same fault in two switches are slim to FA.
I’ve had the nanocom about a week and have been messing with it. Could I have messed up a setting to give a wrong result?

 

[pwood999]

The chances of have the same fault in two switches are slim to FA.
I’ve had the nanocom about a week and have been messing with it. Could I have messed up a setting to give a wrong result?

Not for the Nanocom input values. They are simply what the ECU sees from switches or sensors.

Pin-1 is 12V from BECM.
Pin-2 signals brake on to ABS ECU pin-14, and Diesel Engine ECU pin-31.
Pin-3 to various other places to signal brake on. (BECM, ABS, EAS, Petrol Cruise & Diesel ECU pin-26)

It's just a dual switch with one NO & one NC contact on each side. They should both operate together.

 

[MontyChambers]

yes, I thought as much, do these switches fail often, I have tried everything but the result is always both closed or open!

 

[pwood999]

Check the switches with a multimeter. Also check the ABS ECU inputs for 12V when you press & release the pedal. Look through the RAVe diagram for the most convenient points.

You could also try the other ECU inputs. Several of them show the brake pressed status (EAS, BECM, Cruise).

 

[Grrrrrr]

The chances of have the same fault in two switches are slim to FA.
I’ve had the nanocom about a week and have been messing with it. Could I have messed up a setting to give a wrong result?

Might be worth a search or contact BBS and see if there is a glitch for the Thor model in the Nanocom screen. Diesel works as per GEMS but never tried Thor.

 

[Datatek]

I fitted the new brake switch as per RAVE
Readings are:
Close/Close
Close/Open
Open/Open
I must be missing something here?
ABS/TC dash lights still on.
Did I fit the bulb correctly
The dash lights only came on after I fitted new ABS sensors, brake calipers, ball joints, dust shields, and track rod to the front wheels.
The MOT has become a distant dream over mountains of cash!

The switch should always be open/closed or closed/open.

yes, I thought as much, do these switches fail often, I have tried everything but the result is always both closed or open!

The switches are break before make (or make before brake) so if either the switch is badly adjusted, or possibly with a very slow pedal movement, it's possible that both switches could be open briefly.. But pedal up it should be one open and one closed, pedal down the reverse. I would check with an ohm meter or a pair of test bulbs.

 

[Dippypud]

The switch should always be open/closed or closed/open.

The switches are break before make (or make before brake) so if either the switch is badly adjusted, or possibly with a very slow pedal movement, it's possible that both switches could be open briefly.. But pedal up it should be one open and one closed, pedal down the reverse. I would check with an ohm meter or a pair of test bulbs.

I like using bulbs easier on my thinking ...

 

[Datatek]

I like using bulbs easier on my thinking ...

More reliable too.

 

[MontyChambers]

here’s a thing.
This truck is on springs!
Could that trigger the ABS/TC dash lights?
It’s in the WABCO D section on my nanocom?

 

[FEI]

here’s a thing.
This truck is on springs!
Could that trigger the ABS/TC dash lights?
It’s in the WABCO D section on my nanocom?

no

 

[MontyChambers]

‘

 

[FEI]

Heres abit of a dumb question: But did you actually clear the fault codes on the ABS controller?
What are the current fault codes that the ABS controller gives?

Did you insert the ABS sensors fully? If they not close enough to the toothed wheel they wont give reliable readings.