Code 61 with secondary system removed?

[scorp508]

Originally Posted by tpepmeie

Scorp, if the light is on straight away then it?s likely already programmed to default to full power.

You should have a 1D table in your xdf file for port throttle open tps % versus rpm. That?s the one dom is talking about. Should be zeros.


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Thanks Todd, yes, already confirmed these two tables are all 0s.

"Port Throttle Opening Point vs. RPM"
"Port Throttle Closing Point vs. RPM"

[tpepmeie]

Originally Posted by XfireZ51

Todd,



I?ve not seen anything in the calibration to allow for two injectors ON in idle conditions. My sense is that altho the PW is halved between the two injectors,

Idle would require a PW that would be too small to be distributed to two injectors. Easier for that PW to be controlled by 1 injector. And that?s just my guess about it. I?m sure that someone who knows how to write code could modify it to do so. Perhaps w a large enough displacement, you may need to do it.

Dom, you have to change it in the program code (not the calibration). It?s an instruction change to open at or above zero tps. As stock the instruction is ?above? zero. Is it necessary? No. But I haven?t seen a problem with the short pulse width at idle either. Of course, there is a separate table to make sure that is right for any new injectors.



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[tpepmeie]

Originally Posted by tpepmeie

Dom, you have to change it in the program code (not the calibration). It?s an instruction change to open at or above zero tps. As stock the instruction is ?above? zero. Is it necessary? No. But I haven?t seen a problem with the short pulse width at idle either. Of course, there is a separate table to make sure that is right for any new injectors.



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Btw, to default the valet key to full power in 91+, it requires a one byte change in the program (not a calibration variable). When the ecu initializes at startup, you have to clear a bit (or set it, I can?t remember off hand) so that the mode doesn?t default to valet.




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[tpepmeie]

Originally Posted by scorp508

XfireZ51, I appreciate you sending those over. It looks like mine are currently set to 17.43 and 24.44 as min/max.

Making sure I understand the concept here.

As-is, the minimum kPa to ever open the secondaries is 17.43. Anything under it would result in keeping them closed.

As-is, the maximum kPa to ever close the secondaries is 24.44. Anything over it would result in keeping them open.


By going to 10.41 / 104.51, nearly the outer limits of a 1-BAR MAP sensor, we're telling the car "We really don't care if they're open/closed, don't go trying to force anything for us based on kPA."

Is that close? I appreciate the opportunity to learn.

Scorp, I'm not sure those conversion formulas are correct in that .xdf file. GM used a different transfer function for Vacuum/Baro than they do for MAP. I don't have access to my service manual right now, but you should look at the thresholds for Code 61 for the vacuum values in kpa. I think it is something like min 60kpa to open / max 43kpa to close.

nonetheless, the fix you noted is right... expand the limits outside of anything the vac sensor will see.

[scorp508]

Originally Posted by tpepmeie

Scorp, I'm not sure those conversion formulas are correct in that .xdf file. GM used a different transfer function for Vacuum/Baro than they do for MAP. I don't have access to my service manual right now, but you should look at the thresholds for Code 61 for the vacuum values in kpa. I think it is something like min 60kpa to open / max 43kpa to close.

nonetheless, the fix you noted is right... expand the limits outside of anything the vac sensor will see.

Here we go.

• <21 kPa to the actuators in FULL mode, DTC 61 set.
• Any vacuum at air inlet valve actuators in NORMAL mode, DTC 61 set.

Interestingly even though I had a 61 stored, the engine was not limited to 3000 RPM. Maybe the limitation is only while actively being detected and not for historical codes.

[scorp508]

Code 56 has a helpful approximation chart.

[scorp508]

Originally Posted by tpepmeie

Scorp, I'm not sure those conversion formulas are correct in that .xdf file. GM used a different transfer function for Vacuum/Baro than they do for MAP. I don't have access to my service manual right now, but you should look at the thresholds for Code 61 for the vacuum values in kpa. I think it is something like min 60kpa to open / max 43kpa to close.

I opened a base BMCB.bin and the values with the same XDF are the following.

24.44 max vac KpA to close: This seems to roughly align with the FSM saying if the vacuum to actuators drops <21 kPa it'll set DTC 61.

41.78 min vac KpA to open: This also seems to roughly align with the FSM stating the secondary air inlet valve reservoir tank going <41 kPa triggers the vacuum pump to turn on.


It's possible my existing BIN just has odd values with the 17/24 or whoever set them had an XDF conversion off.

[tpepmeie]

Originally Posted by scorp508

I opened a base BMCB.bin and the values with the same XDF are the following.

24.44 max vac KpA to close: This seems to roughly align with the FSM saying if the vacuum to actuators drops <21 kPa it'll set DTC 61.

41.78 min vac KpA to open: This also seems to roughly align with the FSM stating the secondary air inlet valve reservoir tank going <41 kPa triggers the vacuum pump to turn on.


It's possible my existing BIN just has odd values with the 17/24 or whoever set them had an XDF conversion off.

GM gives the conversion as:

N = E * 2.70045 + 28.7640

N being the decimal value of the raw hex. In BFXB I see 0x55 hex, or 85 dec. for the first value. same for BMCB.

[scorp508]

Thanks, Todd, I also see 0x55H (min vac to open), then 0x26H (min vac to close) of BMCB.

With the conversion you gave...

Min Vac to Open
85 = E * 2.70045 + 28.7640

Works out to E = 20.82 kPa, nearly 21 , and aligns with <21 kPa in full mode setting DTC 61. This looks pretty spot on.

This next one confuses me, unless it should be using a different conversion.

Min Vac to Close
38 = E * 2.70045 + 28.7640

Works out to E = 3.42 kPa. Not sure what to make of that value without reading the code around it, unless it should be using a different conversion or unit of measurement.

-Brian

[XfireZ51]

Here's the conversion formula in the .xdf I have w the values calc'd from a stock $F0 BKKR bin. That's the conversion formula in the .xdf I sent you Brian.
The 10 and 104 value are what Haibeck uses along with others w secondary delete.