TRACS/ABS: 850: lots of error codes but no patern to them

[Cypher007]

ive normally got error 141 and 142 had those for years. brake pedal switch.

now I'm getting 144, 424, and occasionally 444.

its like the abs system is dying. I had 444 the other day and it would not go away even after using switch cleaning lube spray on the abs ecu connector, multiplug to abs block, all the abs fuses in the fuse box, and the abs relay. then the next day it starts working but then throws 144 142 and 424 at me.

whats going on?

I did have a calliper sticking a bit but that's sorted now. could they have forgotten to reattach something or left a sensor unplugged?

on the multi plug that feeds the abs valves I did find some white powder on one contact but cleaned it with the contact cleaner.

the error code descriptions are as follows:

1-4-4 Brake Discs Overheated
1-4-2 Faulty Brake Light Switch, Open Or Short Circuit
4-2-4 TRACS Pressure Switch, Faulty Or Short Circuit
4-4-4 No Supply To Hydraulic Unit Valves

[doingitsideways]

Usual problem is the solder joints on the ABS unit's board dry out and crack, so they lie to you as a result

[DunkinBiskits]

think hes on the earlier "second engine" HUUUUUGE ABS module being that hes
reading obd1 fault codes back.

interested here and following this, as im considering removing my ABS completely as its starting to show signs of age (same system)

[Cypher007]

its a T5R 1994 so on the first version of tracs probably. I know the pressure switch is in the hydraulic block rather than on the master cylinder like the later cars.

I might pull the ECU and reflow the joints as a solution just to see what happens.

apart from the 141 142 errors that its had for the 13 years ive owned it. the ABS has been fairly reliable.

the only other thing that seems to have packed up altogether now is the cruise control. its was hunting slightly before and when it works will do the same now, but ive had the vacuum pump out and checked everything no leaks nothing. I might take some slack out of the accelerator cable and see if that helps.

I think the reason the cruise doesn't work and possible the 424 error is maybe the brake pedal switch needs adjusting.

[scutyde]

Try the following:
on the left (passenger side) strut mount there is a big wide connector. Disconnect it, use some contact spray and put it firmly together.

[Cypher007]

already done. same result at the moment. will check later today. ive got the tracs turned off at the moment, so I can ignore it.

[doingitsideways]

The Tracs is a waste of time anyway and really can't cope with a T5 on boost.

Cruise does tend to hunt a little on the cable throttled cars too.
Mine, although later M4.4, is a little slow to respond to inclines and sometimes overcompensates

[Cypher007]

still same TRACS codes 144 and 424. will check the actual sensor function next. what I don't get is why the ECU thinks TRACS has been activated too many times, hence disc overheat error.

could the hydraulic block have a problem after the mechanic cleaned up the calliper, as he might have pushed the piston in and out, maybe damaging the TRACS pressure sensor? or airlock?

the cruise control used to be spot on, as I live in a very flat area, but now it seems to maintain the speed fairly well but by flip flopping between accelerating and decelerating. I can see it doing it over time on the Turbo gauge. it will spend maybe 5-10s in one position then change to the other for 5-10s back and forth.

[DunkinBiskits]

Originally Posted by Cypher007

could the hydraulic block have a problem after the mechanic cleaned up the calliper, as he might have pushed the piston in and out, maybe damaging the TRACS pressure sensor? or airlock?

id like to think not as pad replacement shouldnt bring on ABS issues but you never know, if there was some dirt or a piece of a seal surfing about in the line then that might well just be enough to cause it.

when were the brakes last bled up? have you got a friend to may be help you re-bleed the system? maybe swap to a ATE blue200 so you can see it arrive at each corner and guarantee youve got a good, free flowing supply.

im not too up on the early ABS, but its saying brake disc overheated. To me that means its monitoring the fluid temp, and its getting above a safe threshold, and temperature in hydraulics means too higher pressure...... pointing to either an obstruction and/or reduced ID on a line or a failed relief valve somewhere maybe

[scutyde]

The overheat error is not due to monitoring of the fluid...
The error gets generated when the TRACS is active (spinning wheel) for a given amount of time . After that the ABS computer "assumes" that the discs are getting too hot and disengages the TRACS function.