Brake warning/pads
DAK
dak at rochester.rr.com
Tue Aug 5 11:03:43 EDT 2003
You might be able to do something to make the cpu in the dash think the
pads are always good. It would involve removing the dash again. I don't
think you can get away with shorting the wires external to the dash. I
have a feeling the majority of false-warnings are caused by bad
connections in the dash PC board. The problem would need to be addressed
there.
If you go into the "board computer" in the dash, use a decent meter and
follow the trace from (I think) pin 10 on the brown 26 pin connector.
You'll find it connects to a resistor near the connector, then goes
across the board to some surface mount components near the 68 pin chip.
There are some resistors and a capacitor ther and the signal seems to go
through them and on to 1 pin on the chip. I'm sure once you find the
right one (sorry, I'm not going to take my dash out again to tell you
exactly which pin!), you could take a resistor (or jumper wire?) and
short that pin to grond. You might need to experiment. I did plenty of
interfacing to micro-controllers back in the day and I'm pretty sure
they wouldn't have done anything "fancy" back in '90 when this circuit
was put together.
David
Mike Del Tergo wrote:
> David,
> Is there any way to do a less thorough job than you did? I don't
> recommend this for all the warnings, but I feel pretty competent to
> decide when my front pads are worn. On my 5000 I just removed the pad
> signal wire to the instrument display. It was clearly marked in
> Bentley, if so, I can't find it for the 200. You mention a bad ground
> via the ECU? Any possibilty of grounding it externally after it exits
> the pads but before it returns to the ECU for grounding? I will have to
> remove the dash again as the last time I did fix the bouncing speed, but
> have managed to short something that is causing my fuel gauge to be
> pegged full, yeah!
> Thx a bunch, pad error light x 2 200s!
> Mike
>
> Mon, 28 Jul 2003 10:49:50 -0400
>
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>
> I just went through this. On mine, the light was coming on (along with
> some other warnings. The classic "bad solder connections" in the
> instrument cluster. I had mine out 3 nights in a row and finally got it.
> If you pull the IC, you can test a pin on the brown 26 pin connector
> (pin 10) to check for continuity with ground. I think mine had about 2
> ohms resistance. That wire runs to both brake pads, then to ground. I
> ended up tracing the circuit path through the PC board, all the way to a
> big 68 pin chip. I re-flowed each solder connection on the way (and most
> others on that board also!).
>
> David
>
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