Page 1 of 2 12 LastLast
Results 1 to 20 of 24

Thread: Swaping a 411 PCM into my 98 Blazer "what to do"

  1. #1
    Tuner
    Join Date
    Feb 2009
    Location
    GA
    Posts
    117

    Swaping a 411 PCM into my 98 Blazer "what to do"

    I thinking of putting a 411 PCM from a 2001 Blazer into my 1998 Blazer. I've got the pinout for the swap but am new to tuning and have never done anything like this before. Can someone tell me what to do with the tune so the new computer will work or direct me to a thread that walks me through it. Thanks in advance.

    Ken

  2. #2
    Senior Tuner
    Join Date
    Feb 2009
    Posts
    1,931
    Look into a mail order tune. HPT does not have the ability to switch between knock sensor types, the knock sensors you have will not work with 0411 as is. If you tell them what you are up to they can make the other required changes and you can fine tune it from there. Do a search on s10forum, lots of write ups on it.

  3. #3
    Tuner
    Join Date
    Feb 2009
    Location
    GA
    Posts
    117
    I have the complete motor and electronics from the 2001. Is it just the knock sensors because I can change them? It sounds like it might be more than just them. I did look at S10forum but I didn't see much on the tuning end.

    Ken

  4. #4
    Advanced Tuner
    Join Date
    Mar 2011
    Posts
    384
    this must be a 4.3L?
    My setup is a 356ci with a 260/268 (212/218 at .050 lift) duration cam with aluminium corvette heads and flat top pistons running 11.3 comp. ratio. with tuned port injection and vortec crank pick up and dizzy running a 411 pcm and 60lb bosch injectors, 1.6 ratio roller rockers. For transmission its a 4l65e built with the monster in a box mega ss kit. All in a 92 chevy ext cab 4x4 pickup with a 98 cab now installed with a third door! running only e85

  5. #5
    Tuner
    Join Date
    Feb 2009
    Location
    GA
    Posts
    117
    Yes it is a 4.3L V6. Sorry I didn't say that earlier.

    Ken

  6. #6
    Senior Tuner
    Join Date
    Feb 2009
    Posts
    1,931
    If you use 2001 engine complete then there will not be an issue. Copy file from 98 computer so you have referance for adjusting fuel gauge and speedo. Disable vats to get it running( if wiring is correct I believe you can relink it later). Without more details of your swap that's all that comes to mind.

  7. #7
    Tuner
    Join Date
    Feb 2009
    Location
    GA
    Posts
    117
    At this point I want to leave the original 4.3 in the 98. It is all stock except for opening up the inlet into the airbox and a limiter on the EGR valve. I'd like to try this swap to pickup the two speed cooling fan control in the 411 computer. Also to learn more about setting up a computer for a custom swap I'm going to be doing with a LS in a 63 Nova I have. I've got a complete 4.3 motor and all the electronics (less the harness) from a 2001 S-10. If you need more info let me know what. Thanks mecaniman in advanced for your help.

    Ken

  8. #8
    Senior Tuner
    Join Date
    Feb 2009
    Posts
    1,931
    I believe the 98 knock sensor is in a different position on the block and a different thread. There is no swapping. Your choicese are: 1. seek a mail order tune to switch to switch the 0411 operating system to the type of knock sensor you have. 2. Put the whole 2001 engine in and source your missing harness. 3. Not run knock sensors(not recommended). The info is all s10forum, you just have to look. I suggest you learn the google function: "site:somesite.com" What you want search for

    "site:s10forum.com" 0411 swap

  9. #9
    Tuner
    Join Date
    Feb 2009
    Location
    GA
    Posts
    117
    Thanks mecanicman. I'm not sure where the 98 knock sensor is ( I think its in one of the drain holes in the block) but I looked at the 2001 block and it's behind the intake. I looked them up on autozone's web site and you're correct they are different. I have looked on s10forum for info but did not try the search you suggest. I found the info for the pinout but did not see much of anything about tuning and nothing about the knock sensor difference. Thanks I'll try your seach.

    Ken

  10. #10
    Tuner
    Join Date
    Feb 2009
    Location
    GA
    Posts
    117
    I did more research and my 1998 knock sensor is in the same location on the block as the 2001 knock sensor. I have the ability to make a bushing to adapt the NPT thread in the block to the Metric thread of the 2001 knock sensor. So the only other thing I see is to wire the 2001 knock sensor correctly to the PCM. Other than turning off the VATS can you think of anything else that I may need? From what I've seen on the S10forum it should work.

    Ken

  11. #11
    Advanced Tuner Shrek's Avatar
    Join Date
    Nov 2011
    Posts
    753
    Quote Originally Posted by gnnova View Post
    ... I'd like to try this swap to pickup the two speed cooling fan control in the 411 computer ...
    You should be able to control the E-Fans based on ECT ... but if your Blazer has A/C you will not be able to control the E-Fans when the A/C is activated (i.e. based on A/C pressure).

    For this functionality you will need to wire an A/C Pressure Sensor and alter the system segment. Typically a Camaro segment is used - but this would cause issues with your Blazer's IPC.

    If you don't have A/C - this is a project a novice could undertake. If you do have A/C - I would recommend a great deal of further self education prior to beginning, or retaining the services of a reputable professional tuner.

  12. #12
    Instead of using a pressure sensor, wire in a relay fed from the AC Clutch Engage signal (you will basicly have two relays being fed from this...this mod and the clutch). This relay then controls the two fan relays. You will need to wire in diodes from the PCM to the actual fan relays to prevent the...we'll call it "AC fan request" relay...from backfeeding to the PCM and throwing codes. Fuse this one like any other circuit and you should be okay.

  13. #13
    Advanced Tuner Shrek's Avatar
    Join Date
    Nov 2011
    Posts
    753
    Quote Originally Posted by sandrock View Post
    Instead of using a pressure sensor, wire in a relay fed from the AC Clutch Engage signal (you will basicly have two relays being fed from this...this mod and the clutch). This relay then controls the two fan relays. You will need to wire in diodes from the PCM to the actual fan relays to prevent the...we'll call it "AC fan request" relay...from backfeeding to the PCM and throwing codes. Fuse this one like any other circuit and you should be okay.
    The downside to this "mechanical" fix is that the E-Fans will run continuously when the A/C is on - even at 80 MPH on the highway - when they are not needed. Also, the E-Fans would either always run on high speed or low speed (depends on how you wire it).

    This "fix" is cheap and easy - but does not allow for flexibility in the E-Fan control (as the PCM control does), and will lead to increased E-Fan wear / decreased E-Fan service life.

  14. #14
    Tuner
    Join Date
    Feb 2009
    Location
    GA
    Posts
    117
    Shrek Let make sure I understand what you're saying because I do understand what sandrock suggest because if I don't switch computers that was what I was planing to do. When you say about installing a pressure sensor you mean one that would close when the pressure in the A/C system got to high due to no air moving accross the condensor. When you say about "alter the system segment", do you mean add a place in the high press line to put a sensor in or do you mean something else. Also what do you mean by "IPC" Thanks for the help. These are the kind of discussions I was hoping for. This gives me options if I don't do the 0411 swap.

    Ken

  15. #15
    Advanced Tuner Shrek's Avatar
    Join Date
    Nov 2011
    Posts
    753
    Quote Originally Posted by gnnova View Post
    ... When you say about installing a pressure sensor you mean one that would close when the pressure in the A/C system got to high due to no air moving accross the condensor ...
    A device that opens / closes is a switch - which is what your 4.3 L S truck uses now in the A/C system. A sensor is a device with a varying output - which is what the 2.2 L S trucks and Camaro (99-02) used in the A/C system.

    To have PCM controlled E-Fans based on A/C activation (the OEM chose A/C pressure as the parameter) requires an A/C pressure sensor mounted in the high pressure side of the A/C system - which your 4.3 L does not have.

    ... When you say about "alter the system segment", do you mean add a place in the high press line to put a sensor in or do you mean something else ...
    Do you own HPTuners or some other tuning software ? In the System segment of the OEM calibration (tune) is where you will find the parameters that apply to E-Fans and A/C controls.

    This portion of the tune must be altered to allow PCM control of the E-Fans based on A/C pressure. The S10 tune won't do this. Most people swap in the system segment from a Camaro - but this may cause you issues with your IPC (see next comment).


    ... Also what do you mean by "IPC" Thanks for the help. These are the kind of discussions I was hoping for. This gives me options if I don't do the 0411 swap ...
    IPC = Instrument Panel Cluster - or your dash gauge cluster in common language. The Camaro system segment is not 100% compatible with the S10 IPC. For example, if the truck is an automatic, and you used a Camaro system segment, the LED gear position indicator in your S10 IPC would initially be blank - until you addressed this in the tune.

    I don't mind providing you with some information regarding the potential issues of your project - such that you are able to make an informed decision about proceeding or not - but I won't provide step by step instructions - either learn to do this yourself via a lot of research, or hire a professional tuner.

  16. #16
    Advanced Tuner
    Join Date
    Mar 2011
    Posts
    384
    if he already has a on off pressure switch on the high side of the ac he could wire that to the relay and control the e-fans with that and it should turn the fans off at highway speed cause the high side shouldn't be at a high pressure
    My setup is a 356ci with a 260/268 (212/218 at .050 lift) duration cam with aluminium corvette heads and flat top pistons running 11.3 comp. ratio. with tuned port injection and vortec crank pick up and dizzy running a 411 pcm and 60lb bosch injectors, 1.6 ratio roller rockers. For transmission its a 4l65e built with the monster in a box mega ss kit. All in a 92 chevy ext cab 4x4 pickup with a 98 cab now installed with a third door! running only e85

  17. #17
    Tuner
    Join Date
    Feb 2009
    Location
    GA
    Posts
    117
    Shrek Thanks for the clarification. I'm sorry if I made you think I was asking tomuch but being new to this and you made assumptions that I new what you ment by segment and IPC was wrong. I have not worked with any Camaro A/C system as far as the way GM controls the E-fans or clutch so I didn't have a clue on that part and all the seachs I made did not talk about it. I have done alot of research but I'm sure you know that it depends alot on the words you use for the search on wether you get what you want. What you told me in the last reply was great. It made much more sense and I know what I'm getting into now. By the way I do know what the difference is between a sensor and a switch but not knowing you and that some people interchange the words needed clarification. I'm not sure what the high side pressures are on my system yet but I did a quick look on ebay and there are binary and trinary switchs for R134 that may work to control the fans on low speed for A/C. So wyochimneysweep I may try it that way if mecanicman doesn't get back to me on wether there is anything else I need to look at for the 0411 swap. Thanks again for the help.

    Ken

  18. #18
    Advanced Tuner Shrek's Avatar
    Join Date
    Nov 2011
    Posts
    753
    Quote Originally Posted by wyochimneysweep View Post
    if he already has a on off pressure switch on the high side of the ac he could wire that to the relay and control the e-fans with that and it should turn the fans off at highway speed cause the high side shouldn't be at a high pressure

    With your 4.3L S truck, two pressure switches protect the A/C system. If the A/C pressure falls below 21-25 PSI, then the A/C low pressure switch will open. This will disable the A/C compressor operation. This switch will close at 38-42 PSI to allow A/C operation.

    If the A/C pressure exceeds 410 PSI, then the A/C high pressure switch will open. This will disable the A/C compressor operation. This switch will close at 350 PSI to allow A/C operation.

    Take a look at an OEM 2002 Camaro tune - which was originally equipped with E-Fans - specifically the circumstances when the E-Fans are commanded ON by the PCM.

    The Low speed fan was generally commanded ON at 215 PSI (or greater), and OFF at 190 PSI (or less). The High speed fan was generally commanded ON at 248 PSI (or greater), and OFF at 208 PSI (or less).

    In the Camaro tune both E-Fans are commanded OFF above 65 MPH - if the ECT (engine coolant temperature) thresholds are below the E-Fan activation point.

    After an examination of the above, it should become obvious that wiring the E-Fan control to either of the existing A/C pressure switches (Low or High) in your S truck, will cause the E-Fans to run when they are not required - they would probably run continuously (or virtually continuously) when the A/C is activated.

    This will keep things cool - but it will prematurely wear out the E-Fans. This approach is really not that much different than simply wiring the E-Fans directly to the ignition switch circuit.

    In the end, if this is a stock S truck then this E-Fan project brings with it little benefit and significant cost (both time and money).

    If this is just something you really want to do - no worries - it can be done. The wiring harness can be configured for an A/C Pressure Sensor, and for the P01 style PCM (the 2001 PCM you have). The PCM can also be configured to work with either type of knock sensor, the A/C Pressure Sensor, and E-Fans.

    It just comes down to how much money you want to spend, what compromises you can live with, and your own skill set.
    Last edited by Shrek; 07-02-2012 at 04:59 PM. Reason: - additional info

  19. #19
    Tuner
    Join Date
    Feb 2009
    Location
    GA
    Posts
    117
    Thanks for the info.

    The Low speed fan was generally commanded ON at 215 PSI (or greater), and OFF at 190 PSI (or less). The High speed fan was generally commanded ON at 248 PSI (or greater), and OFF at 208 PSI (or less).
    I had no plans to use the existing switches because I know how they work and settings, but I didn't know how the camaro setup worked. I found a trinary switch that has a componet that closes at 225psi and opens at 185psi which is close to the camaro low speed fan settings. I can easily plumb a additional switch to the High pressure line. So if the camaros use these pressures to operate the low speed then the fans should turn off at speed when the high pressure drops. The switch is only 20 dollars and I can use HPtuners to turn on the fan from pin #9 in the 98 computer to operate the fans in high speed for eng temp control. I'd still like to do this with the 0411 computer for the swaping experience but this looks like it can be done at a reasonable cost.

    Also another reason for going with the e-fans is increased gas milage. I've been able to get close to 20mpg with driving habits and some changes but about a month ago the milage jump to almost 22mpg. I was amazed at first but found out why when temperatures started getting into the 90's. Then the blazer started to overheat in traffic. I replaced the clutch on the fan and now my milage went back to just under 20mpg. So if I can get 2mpg its worth it. Thanks again

    Ken

  20. #20
    Senior Tuner
    Join Date
    Feb 2009
    Posts
    1,931
    From my stock 2002 sonoma operating system which uses the 0411 pcm.
    Think the red highlighting speaks for itself.