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iball said:
I guess it's for the 40TE Auto-tranny?
"The solenoid assembly also contains pressure
switches that monitor and send hydraulic circuit
information to the PCM/TCM. Likewise, the pressure
switches can only be service by replacing the assembly.
PRESSURE SWITCHES
The PCM/TCM relies on three pressure switches to
monitor fluid pressure in the L/R, 2/4, and OD hydraulic circuits. The primary purpose of these switches is to help the PCM/TCM detect when clutch circuit hydraulic failures occur. The range for the pressure switch closing and opening points is 11-23
psi. Typically the switch opening point will be approximately one psi lower than the closing point. For example, a switch may close at 18 psi and open at 17 psi.
A Diagnostic Trouble Code (DTC) will set if the
PCM/TCM senses any switch open or closed at the
wrong time in a given gear.
The PCM/TCM also tests the 2/4 and OD pressure
switches when they are normally off (OD and 2/4 are
tested in 1st gear, OD in 2nd gear, and 2/4 in 3rd
gear). The test simply verifies that they are operational,
by looking for a closed state when the corresponding
element is applied. Immediately after a
shift into 1st, 2nd, or 3rd gear with the engine speed
above 1000 rpm, the PCM/TCM momentarily turns
on element pressure to the 2/4 and/or OD clutch circuits
to identify that the appropriate switch has
closed. If it doesn’t close, it is tested again. If the
switch fails to close the second time, the appropriate
Diagnostic Trouble Code (DTC) will set."

Seems too smart to fool with a resistor..I think we would need a microcontroller to fool it..but then we need to find the sense wire for the gear, since it's looking for specific shift patterns. Who knows if the full autotranny code is even in there? :eeeek:
 

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phrozen said:
Oh come on. How hard would it be for one of them to anonymously post somewhere that says: X.xX volts on pin XX, y.yy volts on pin Yy.

Oh well. We'll get it done. Worst case, all we have to do is get someone with a GT cruiser automatic and ride around in their car with a recording voltmeter on each critical wire.
Thats only if the signals from the tranny are analog. At this point, for all we know the tranny could be riding on the PCI data bus. Most instrumentation for the PCM seems to be analog..only feedback and control seems to be digital in this car.
 

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glhs837 said:
Just from the book, I picked them as examples of code that are not emmisions related. See, some states garage/inspection station owners lobbying groups get the standards set so that ANY codes is evidence of tampering and therefore a fail.

Which leads to lucrative repair/reinspections.
Someone mentioned in another thread that the Saab ECU's use after-fire cylinder ionization to detect misfires. Hmm :)
 

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phrozen said:
s3 also has the returnless RRFPR (it sounds funny if you say it outloud). I know it rises with boost pressure, but at what rate and where is it without boost?

At least disconnect the hose running to the regulator so that so it never sees boost. Then it should cut down some of the fuel pressure. Perhaps connecting it to a constant vacuum source would cause it to reduce the fuel pressure back to stock levels???

Anyone know more about that?

That's odd that NY would do that. They just trust the OBD to be right? Amazing. I think in NJ we have OBD and a dyno. Maybe I can give them a few $$ to measure my HP while I'm on it... ;-)

But seriously... We need to come up with an electronic hack to make the s3 kit pass OBD as-is. I can't do much really, until I get mine.... It's on order, but not here yet...
Yea we need to know what the base pressure is. Applying vacuum to it may not work, or it might. Either way, it would take some tuning to make it work right. Hell, I don't even know how a dead-head FPR works...
 

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iball said:
Our cars don't have CPUs. They have PCMs.
Just felt like picking nits today....
CPU/PCM/ECU it's all the same :)

Our ECU is located in the front of the engine bay, vertically mounted just behind and below the driver's side headlight. Placing it in the engine bay is likely just due to proximity. From what I read, there's really nothing special going on here that would warrant a short lead length. I figure you could put it in the cabin, you'll just need to shove the wires to the C4 connector through the firewall. Since the C4 connector is so big, you will likely need to cut and splice.
 
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