Tuning my old 2000 Silverado with some mods. Have a few HP Tuners questions.

[jameswis01]

Hello. To start, The tune file I'm attaching, is the stock 2002 Tahoe Flex fuel tune from the repository... I'm about to explain why...

1st. This WAS a 5.3l LM7 truck. I've swapped it for an LQ9 with some upgrades. Cam, Trunions, Springs, Bearings, Molly Rings, Double Chain, HV Pump, 243 heads... Maybe boosted later... My injectors are going to be 80lb'ers... And I'm adding in the E85 Sensor..

I'm looking to make this Flex Fuel friendly while still using the Drive By Cable throttle body, by flashing my p01 ECU.. It looks like the stock tune from an 02 Tahoe has the flex feature... Now. Here's my questions...

1st) When I open ANY tune and choose the "OS" feature, I don't see the upgrade options that people show in youtube videos and such.. The only time I ever saw this was when I 1st tuned my 2000 Silverado, but its never shown up again. I have the editor setup for "advanced" so I'm not sure why i don't see anything under "OS"... Can anyone tell me why i don't see something like "Speed Density - Enhanced" or "Speed Density - 2bar" or anything at all?

2nd) I want to know if this 2002 Tahoe tune is setup for "Drive By Wire" or "Drive By Cable"... Where do I look for it, and what is it called (the setting or feature)? This tune was from the repository.. Is there a way I can tell from a setting somewhere?

3rd) I'm going to be running headers so I'll no longer need an EGR valve. How do I disable this in tuning? (I understand what it does, and I'm using a newer 04 intake, without an EGR port in it either. I have no emissions inspection in my state, so its not a problem for me.)

4th) I want to make sure there is no AirPump setup in this tune. My truck never had one, but since the 2002 tahoe tune is from the repository, IDK if it did or not. How can I verify this?

Finally. I have a Wideband O2 that runs to a gauge in my cab. I'm wondering if there is a replacement wideband sensor that would plug into the factory wiring harness in place of the stock 02 sensor, and provide additional data to the ECU? (I'm not sure if this is even possible, but I figured I'd ask)

Thanks for your patience and your help everyone...
James
P.S. Have a great day at the track... Even if your track is the local parking lot in the rain..

[blindsquirrel]

1st) When I open ANY tune and choose the "OS" feature, I don't see the upgrade options that people show in youtube videos and such.. The only time I ever saw this was when I 1st tuned my 2000 Silverado, but its never shown up again. I have the editor setup for "advanced" so I'm not sure why i don't see anything under "OS"... Can anyone tell me why i don't see something like "Speed Density - Enhanced" or "Speed Density - 2bar" or anything at all?

No idea... your repository file shows Speed Density Enhanced and Speed Density 2 bar available.

Once a file has ANY of the custom OS options applied, ALL of the other options are removed from the OS tab. They can't be removed afterwards or undone other than by reverting to an earlier file from before the option was applied. To check for this, go to Tune Details and look at the OS number. For your Tahoe file, stock will show "Operating System 12216125". If it's been changed, the OS tab will be blank and Tune Details will have "Operating System 12216125 -> 1252013", if it's had the 2 bar OS applied.

2nd) I want to know if this 2002 Tahoe tune is setup for "Drive By Wire" or "Drive By Cable"... Where do I look for it, and what is it called (the setting or feature)? This tune was from the repository.. Is there a way I can tell from a setting somewhere?

screenshot.13-06-2022 00.15.01.png

1 = yes, 0 = no.

3rd) I'm going to be running headers so I'll no longer need an EGR valve. How do I disable this in tuning? (I understand what it does, and I'm using a newer 04 intake, without an EGR port in it either. I have no emissions inspection in my state, so its not a problem for me.)

The Tahoe file has EGR already disabled -
Engine > Exhaust > General: Disabled, and
Engine > Spark > Advance > Base Corrections > EGR is all '0's, and
DTCs P0400-P0405 are set to No Error Reported.

4th) I want to make sure there is no AirPump setup in this tune. My truck never had one, but since the 2002 tahoe tune is from the repository, IDK if it did or not. How can I verify this?

Look at Engine > General > AIR Pump: Disable ECT = 285*F.
Description for that item says
[ECM] 2020 - Air Pump Disable Coolant Temp: Below this engine coolant temperature, the air-pump is disabled.
So, if the truck had an AIR pump it would never be used, so you can ignore it.

Finally. I have a Wideband O2 that runs to a gauge in my cab. I'm wondering if there is a replacement wideband sensor that would plug into the factory wiring harness in place of the stock 02 sensor, and provide additional data to the ECU? (I'm not sure if this is even possible, but I figured I'd ask)

No.

----------

Something that will help you find these things on your own is, type CTRL+N to open the navigator. You can search by the parameter number if that's all you know ('2020'), or by keywords ('EGR', 'AIR').

[jameswis01]

Wow. Thanks a lot for all that info. It was just the answers I needed. And that would explain why I don't see anything in OS tab.
Everything else is dead on with what I needed to know going forward.
Thanks again for the quick reply and great answers!!!

[jameswis01]

Now I have another question. I'm looking at adding electric fans to my P01 ECU.
I see a relay kit on Amazon with 2 wires. Looking at the Pinouts it says one connects to:
Pin 42 (Low speed cooling Fan Relay Control) - And this would make perfect sense, assuming its the blue connector...
The 2nd pin connects to:
Pin 33 (HVAC Recirculation Door Control) - On the red connector....
What does Pin33 do normally? Do i leave the HVAC Rec Door Ctrl wire hooked up as well? What happens if that is disconnected? Does my AC not have a recirculation mode anymore?
I hope this question makes sense...
Thanks.

[2xLS1]

Auto A/C recirculation turns on the interior recirculation function independent of the dash switch when a switch in the high pressure A/C line senses the pressure getting too high to try and lower the pressure in the system. Removing the wire will disable that function. Recirculation will still work with the dash switch. Be aware that using the harness with 2 wires going to the PCM (really for 03-07 classic trucks) on 99-02 trucks will only allow fan turn on with engine temps. Not with A/C pressures. This can sometimes be a problem with airflow across the condenser when stopped with A/C on. Harness made specifically for 99-02 trucks only have 1 trigger wire going to the PCM and 1 trigger wire going to the A/C compressor clutch because those vehicles do not have a pressure sensor in the A/C, only a pressure switch. You only get low speed fans with coolant temp and high speed fans when the A/C compressor is energized. For fan operation with both coolant temps and A/C pressures on 99-02 trucks you need to modify the vehicle with something like this.
https://www.performancetrucks.net/fo...ontrol-553385/

[jameswis01]

Does the P01 ECU have a way to program low and high speed settings? Something like:
Fans off @120degrees or less...
Fans on Low @ 121-150 Degrees...
Fan on High @ 151and up....

If I can make it work, I have an 04 Suburban with an L59 flex fuel motor, but its drive by wire. I want to keep my cable setup. So I'm not sure if it has the mosfet required to drive the IAC. I'm hoping it does. If not, I may try soldering one in, as I've seen people do it on youtube.. And before anyone says anything... I'm a soldering expert as I do Electronics Repair for a living. My sloppy soldering jobs are WAY better than most other people's best soldering work. lol

However, If I can make the flex fuel sensor work with my P01 ECU, I'm good with that as I really need this truck up and running and it would save me a lot of time, by not messing with the wiring harness pins...

My other last option would be to use a 2nd screw in temp sensor with a custom PCB with potentiometer (variable resistor) to control the temp, and use that to control the electric fans. An Arduino could be programmed to turn on the low speed relay at a certain resistance input from the sensor, then turn on the high speed relay when the sensor gets to a certain point. However, this would again add more time to this project and it needs done by June 29th...
Thanks.

[kevin87turbot]

The P01 PCM will control the On/Off temps for Fan1 and Fan2 independently.

[jameswis01]

So what would the wiring look like for that? Would I still follow the Pin 42 (blue) and Pin 33 (Red)? I don't want to tie into the AC system pressure switches into the fans at all.. Thanks

[RDF1]

wire it the same as the 2005+ trucks

[jameswis01]

wire it the same as the 2005+ trucks

Thanks.. This was EXACTLY what I was looking for...

[jameswis01]

Next question. Do we know what connector pin type I need to add the wires to my ECU? Do we have a link for the pins themselves from Amazon or something?
Thanks

[blindsquirrel]

Buy used connectors off ebay. Pigtails, connector cores, whatever search terms turn up the connectors with all the wires chopped off. Extract wires with crimped terminals as needed and plug into your existing connector bodies. The crimping tools are specialized and generally cost a lot more than just buying used connectors.

example: https://www.ebay.com/itm/264635923312

[jameswis01]

Thanks, But I found the connectors.. Aptiv (Formerly Delphia) Part# 12084912..
I own the crimpers for these types of connectors, as I repair electronics for a living. I was just hoping someone was like "Hey, here's a link to amazon for some." Oh, and btw...
"Here's a link to Amazon for some." lol
https://www.amazon.com/dp/B07K418K36...hk_typ_imgToDp

Now onto my next question....
Are all GM Flex Fuel sensor outputs the same? Or do I have to use one from a Silverado, Suburban, Tahoe, Yukon and so on... Or would one from something like an Impala work? (I know the physical design is different, I'm just wondering if anyone knows if the signal outputs are the same. I'm guessing they are since its only 3 wires total... Power, Ground & Signal to ECU.)
Thanks

[jameswis01]

So for anyone still looking into this thread. I've ran into a new issue. I've installed my two new electrics fans using the Blue Pin42 as Fan1, and the Red Pin 33 as Fan2... But when I go into VCM Scanner and try to trigger FAN1, both fans turn on. When I try to trigger just FAN2, nothing happens. I know I definitely connected them to the correct pins. Does anyone know what maybe going on?

Here is a link for the Amazon part I've used that have the Relays and the wires ping the pins for the ECU connected... It says for 05+ but they color coded the ecu wires blue and green instead of blue and red. I used Blue in the Blue ECU connector and Green in the Red ECU connector...
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Thanks.

[blindsquirrel]

Low speed is only the one output pin, high speed requires both outputs at the same time because of the way the 3-relay setup has to switch the fans from series for low speed to parallel for high speed.

This is a different ECM but the fan relays work the same, and I already had these in my attachments, so this is what you get...

low speed.png high speed.png

[jameswis01]

I'm not following what you're saying... I have wires connected to both pins on the ECU. Low & High Pins 33 and 42 respectively... So what I'm saying is that when I trigger "FAN2" (inside the ECU), nothing is happening. It doesn't switch to "high speed"... It stays on low speed. I'm trying to figure out why.

[gtstorey]

Have you confirmed that those pins are grounding when commanded?

[blindsquirrel]

You have to command BOTH 1 AND 2 on AT THE SAME TIME. Only doing Fan 2 by itself is not how it's wired to work. Needs ALL 3 RELAYS ON at the same time for both fans to run in high speed. Only one relay is turned on to get low speed.

[jameswis01]

You have to command BOTH 1 AND 2 on AT THE SAME TIME. Only doing Fan 2 by itself is not how it's wired to work. Needs ALL 3 RELAYS ON at the same time for both fans to run in high speed. Only one relay is turned on to get low speed.

When I command Fan2 to come on this is After I've already command Fan1. When Fan1 only command, both fans run on low. Toggling FAN2 does NOTHING at all. By itself, or with fan1 on.

[jameswis01]

Have you confirmed that those pins are grounding when commanded?

Yes. Both pin 33 and pin 42 are grounding when commanded, respectively. I even just swapped the wires going to the relays just incase, but it didn't seem to make a difference. Only thing that changed is now the command for FAN1 does nothing, and both fans come on LOW when I command FAN2 to turn on. (That's how I know both pins are grounding)... At this point its obviously something in the wiring harness for the fans that was put together incorrectly.