Well guys I'm baaaaaaaaaaaaaack!!! Cooling fan OS problems.

:help: This should be simple but as with most of my problems, has turned into a nightmare.
This is that daily driver Volvo with an LH6/4L60. Because the application is from an SUV it had an engine driven fan. Obviously I swapped it to a dual wire electric fan from a Volvo. Simple 3 wire...low speed/high speed/ground on a single electric fan. I utilized an aftermarket fuse panel with 2 fan relays. After repinning 2 terminals from the E40 to be able ground the 2 relays I reprogrammed the GTO fan settings into my tune. Now the low speed fan will come on at a certain temp but will not shut the fan off until I turn the key off. Even after the temp drops to below the thermostat temp. Also the high speed relay will NEVER kick on, even after pulling the fuse for low speed to make certain the engine temp goes high. I HAVE manually grounded low/high speed ECU terminals to verify proper fan operation. Different temp settings don't help either.Also I'm NOT able to log fan on/off because the OS is from an engine driven fan setup.

I tried a FULL flash with GTO settings but still no luck. So I now look to the powers that be (hint,hint) to find out if I need a GTO OS to be able to use my electric fans. I probably don't mind doing this as I have not been very happy with DOD operation. SO I guess my question is wether or not an OS change is in order for proper electric fan operation?

For those of you wondering about DOD/AFM use in a engine swap situation wonder no more. I see now that the engineers at GM had there hands full with N/V/H issues when they designed this. I've never driven a DOD GM truck in DOD mode. The exhaust on mine sounds awful in DOD mode. While my exhaust is not loud...2 CATS, single 3 inch stainless, 2 Magnaflow straight thru and long tube headers. Car is completely unassuming in V8 mode until you step on the gas and and light the tires! In V4 mode the vehicle shakes violently and has a horrible 4cylinder drone and feel.

I would not waste my time trying this DOD thing again. Next one will be full on GTO or Camaro setup. This would be a COMPLETE sleeper with a small turbo setup.


Thanks for the help, sorry for the rambling! John:rant:

From memory the high speed fan is switched by the BCM and the low speed fan is switched from the PCM.

So in an engine conversion you will have to switch both your fans from the low speed circuit and adjust the temps in the low speed table.

also the signal wire from PCM for fans is positive switching (I think) the opposite of the fuel relay signal anyways.

Well the GTO fan relays are grounded by the ECU. Here are both diagrams. I still think it is an OS problem. Just need the hire ups to verify.


Thanks, John......In want of a mega-burnout!

What are each of those 2 diagrams from...?

You mentioned 2 relays, but the second diagram shows 3 relays (require 3 relays for series-parallel fan switching)...

You have it wired up like the second diagram...?

The second diagram is the GTO with 3 relays. I did not use 3 relays. My fan has one ground, one low speed wire, 1 high speed wire. I used pin 36 to ground my low speed relay and pin 56 to ground my high speed relay. Extremely simple setup....It matches my IQ.

The other diagram is the GMC ENVOY in which my E40 came from (it's mother so to speak). Just to show you how the E40 was utilized in its clutch fan setup. I wanted to show you THAT MY HEAD IS STILL DEEPLY INSERTED IN MY BUM!!! Sorry I yelled.

Funny thing. Today the low speed works on/off just fine. The high speed does not work at all. Had temps up to 225f just now and no high speed.

I just need to find out if my problem is OS related or am I missing a tuning thing. All fan boxes checked and temps just like my stock 06 GTO tune.

I think the third relay in the GTO reverses polarity or something.

Ah, Volvo fan, I see...

Is this how the Volvo fan works:
- supply low speed signal to get low speed,
- supply both high and low speed signals to get high speed,
??

Did you check with a DMM to see if you're getting the high speed fan signal (pulls to ground)...?

Do scantool bidir controls work with this ECM...?
If they do you can command fan high speed and probe the circuit with the DMM.

I too like things simple... :cheers:

Yes I checked the 56 pin of the ECU to see if the circuit would ground. It will not. I truly think this is an operating system function.
Remember the saying....."Mix and match and you will see, it won't work as it's supposed to be"!



On the bright side. This thing does a MASSIVE burnout. The wife is not really happy about the burn marks in our driveway.


Thanks for thinking of me Joecar, John:sneaky:

I cant help with your problem, sorry. But I can say that even on TrailBlazer/Envoys with the 5.3 sound like crap with anything but the stock exhaust once DOD/AFM kicks in. You can turn it off via EFILive, I dont know what you have to change but I know it can be done. You can also change when it kicks on (so maybe change it so DOD only kicks on on the hwy).

I did shut it off Erik. It just was not bearable. It stays on far too long when approaching a stop. Just about stalls the engine when stopping. Once the fueling is tuned I might try it again. Actually there is a reflash for this problem per TSB # bla bla bla!







2006 GMC Truck Envoy 4WD V8-5.3L VIN M
Vehicle Level Powertrain Management Computers and Control Systems Technical Service Bulletins All Technical Service Bulletins Engine Controls - Low Speed Deceleration Shudder


Engine Controls - Low Speed Deceleration Shudder
Notes

Bulletin No.: 06-06-04-056

Date: October 24, 2006

TECHNICAL

Subject:
LH6 Engine Low Speed Deceleration Shudder, Chuggle or Pulsation (Reprogram ECM)

Models:
2006 Buick Rainier
2006 Chevrolet TrailBlazer, TrailBlazer EXT
2006 GMC Envoy Denali, Envoy XL Denali
2006 Saab 9-7X

with 5.3L Vortec V8 Active Fuel Management Engine VIN M - RPO LH6)

and Two-Wheel Drive ONLY Vehicles with 4L60-E Automatic Transmission (PRO M30)

Attention: The following service ECM calibration update may slightly increase fuel consumption and should only be used if the customer commented on the shudder conditions outlined in this Service Bulletin. Most vehicles will never experience this shudder.

Condition

Some customers may comment on the following low speed deceleration shudder, chuggle or pulsation conditions:

Shudder feels like a brake pulsation and/or chuggle on deceleration from approximately 40 km/h (25 mph) to 24 km/h (15 mph).

Shudder will continue if brakes are released and the vehicle coasts in 40 km/h (25 mph) to 24 km/h (15 mph) speed range.

Shudder is significantly diminished or eliminated if A/C is "Off' due to reduced engine load.

Shudder is eliminated if vehicle is put in D3 mode, which disables 4 cylinder mode (4 cyl mode is permitted when trans is automatically in 3rd or 4th gear, but disabled when PRNDL is placed in the 3rd position).

Selectable Service Calibration Number

Use this selectable service calibration Only for vehicles with low speed deceleration shudder, chuggle and/or pulsation experienced at high temperature and low altitude. A slight increase in fuel consumption may occur.

Calibration 12614807 is selectable with 12606496. The title line states: "New calibration to address vehicle shudder during decel between 25 and 15 mph, feels like brake roughness. Should be used for complaint only as some loss of performance and fuel economy may occur".

Correction

Reprogram the ECM with the latest calibrations if the above concern is encountered. An updated ECM calibration is now available to address this concern. This calibration, or any that follow, is designed to address this concern. Refer to Service Programming System (SPS) using the appropriate Service Information (SI) procedures. The new ECM calibrations will be available to dealerships in TIS2Web (website version of TIS) version 10.0 for 2006 beginning 10/01/2006. If you cannot access the calibration, call the Techline Customer Support Center and it will be provided. As always, make sure your Tech 2(R) is updated with the latest software version.