0411 functions questions

Hi, first time poster here. I have a 92' K1500 Blazer 5 speed manual with a 1614299 (747) ecm. Started wiring a harness for a 0411 swap and am not clear on a few functions of this ecm. Donor harness is from a 00' express van. Plan is to use EFI live, what you guys are on the verge of doing with flashing a LS1 ecm is way over my head.

I have quite a few questions but will just ask one for now.

C2 Red 17 is A/C request. Right now I have electric fans setup with dk grn/wht going to a relay to engage high speed fan. Thinking I can eliminate this relay if my assumption that R17 switches R33 (high speed fan) to ground through the ecm?

BTW is there a book that explains all of the functions of a 0411?

Quote:

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Originally Posted by ecir45

Hi, first time poster here. I have a 92' K1500 Blazer 5 speed manual with a 1614299 (747) ecm. Started wiring a harness for a 0411 swap and am not clear on a few functions of this ecm. Donor harness is from a 00' express van. Plan is to use EFI live, what you guys are on the verge of doing with flashing a LS1 ecm is way over my head.

I have quite a few questions but will just ask one for now.

C2 Red 17 is A/C request. Right now I have electric fans setup with dk grn/wht going to a relay to engage high speed fan. Thinking I can eliminate this relay if my assumption that R17 switches R33 (high speed fan) to ground through the ecm?

BTW is there a book that explains all of the functions of a 0411?

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I never was able to get the 0411 to control both fans. The Express has a GM dual fan setup off a newer FWD V6 car (06 Malibu IIRC) and uses the 3 relay F-car fan control setup. I added a 3rd gen F-body, C4 Vette style 180°F lower temperature fan switch to the passenger side cylinder head.

The ECM triggers the low speed fan operation via the auxiliary fan option. The high speed is triggered via coolant temp. If the ECM were to fail to turn the fans on, the coolant switch would ground the relay to run a single fan on high speed.

HI Fast, well that not encouraging. Don't you use EFI live?

Right now my fan setup is independent, will probably leave as is until bugs are worked out after installing OBDII.

How it is wired now.
Attachment 5214
Am planning to rewire like this.
Attachment 5215
underhood
Attachment 5216
Using 2x4 for length from under dash to rear of engine
Attachment 5217

Was hoping my first question would be a simple answer :). A/C request I'm pretty sure tells the ecm to idle higher. Just haven't found anything in my searching that clearly states the 0411 would also use A/C request to trigger fan #2. Looks like I will have to try it out when up and running.

One thing I was hoping for with the 0411 was to be able to set my own on-off temps since I haven't found a temp sensor that switches to my liking.

From the Fans folder in EFI Live:

Quote:

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Select the type of cooling fans fitted to the vehicle, the PCM supports the following types -
1. Series Parallel Fans - Where both Fan Outputs (1 & 2) are used to control two fans.
2. Auxiliary Fan - Where just Fan1 output is used, generally these vehicles will also have a mechanical clutch fan.
3. No Fans - Only a mechanical clutch fan is fitted
4. EV Fan - Used on later model vehicles, the fan speed is variable by means of a PWM output.

Only the following values may be entered into this table:
- Series Parallel Fans
- Auxiliary Fan
- No Fans

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Thanks for the screen shot!!!

Had this schematic saved for when the time comes to possibly include the 3 wire pressure sensor.
Attachment 5220

Moving on to next question. The ecm has four grounds going to near t-stat housing. My C200 has a common ground for ALDL, Gauges, etc. that goes to near t-stat housing.

Can all of these be bundled under dash with one larger conductor going to front of engine or should the ecm be separated from the C200 common one?

Ignition module, o2 sensors, maf all have there own grounds with module and maf going to near t-stat housing and o2 sensor to rear of engine.

I guess my main question is does it really matter where the grounds terminate on block?

I know you want a ground to have its shortest path but having battery ground at front of engine, engine to frame and body at rear of engine, o2 at rear of engine and everything else near t-stat housing just makes me wonder if there is a standard practice.

Wondering if I can mount a insulated jb on the firewall near rear of engine and just run all grounds to it for a cleaner easier to get to install.

Quote:

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Originally Posted by EagleMark

From the Fans folder in EFI Live:

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HP Tuners has the same thing but I have been unable to get the 2nd output to work with a 5.7 Express calibration. I do not believe it is in the code for that application

Had this screen shot saved for HP tuner
Attachment 5221