Subject: Is it possible to repair the "Computer" (ICU)

[Hayes Myers]

Caps fail the most.

On 8/24/11, Mike Arman <Armanmik at earthlink.net> wrote:
>>  <mboucher70 at hotmail.com>
>> To: Tony Hoffman <auditony at gmail.com>,	"quattro at audifans.com"
>> 	<quattro at audifans.com>
>> Subject: Is it possible to repair the "Computer" (ICU)
>
>
>
> Maybe.
>
> First, I'd look for a used one at a pick & pull, they usually get under $100
> for them (assuming they
> don't know what it is out of and you don't tell them). Buy a bunch of low
> value crap, cardboard
> stiffeners, raggedy floor mats, so the "pile" you take to the register when
> you cash out looks like
> low value garbage.
>
>
>
> Going into yours - In troubleshooting electrical and electronic devices,
> I've always found that the
> parts that work the hardest are usually the ones that break. Check for
> anything burnt or toasted in
> the power sections of the ECU - follow your nose, do a sniff test for
> toasted components or PCB
> traces. A bright light and a magnifying glass are invaluable.
>
>
> I haven't been paying a lot of attention to this thread, but I think you
> were talking about a
> problem with no power to the ISV.
>
> The ICU controls the ISV, but I'd be willing to bet it is through a relay
> somewhere - an ISV likely
> takes more current than an ECU is comfortable with. Follow the wires from
> the ISV to find the relay,
> test the relay (press contacts closed, see if the ISV energizes), see if
> there is power TO the
> relay, then follow the control wire back from the relay to the ICU. If it is
> OK, open the ICU and
> find what is connected to that terminal on the PCB edge connector. Look for
> a toasted PCB trace or a
> big power transistor - probably a surface mount device, little black
> rectangle somewhat larger than
> the other little black rectangles liberally scattered around the board. It
> will have THREE leads,
> anything with eight or more is a logic IC, not a power transistor or
> switching transistor.
>
>
> The temp sensor talks to the ICU also, and tells it to turn the ISV on and
> off - make sure the temp
> sensor and wiring are also good.
>
>
> The pick and pull is a good choice BUT if there is a problem in the wiring
> somewhere else, the new
> ICU won't work any better than the old one.
>
> Can you borrow one to try?
>
>
> Hope this helps, these are just my thoughts on this.
>
> Best Regards,
>
> Mike Arman
> 90V8Q
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