Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

4 wheel drive won't engage on '94 S10 4x4 w/233 transfer case

Discussion in '1983-2005 S-Series models' started by Murraywarwaruk, Mar 26, 2002.

  1. Murraywarwaruk

    Murraywarwaruk Newbie

    Joined:
    Mar 26, 2002
    Posts:
    1
    Likes Received:
    0
    4 wheel drive won\'t engage on \'94 S10 4x4 w/233 transfer case

    I have a '94 S 10 Blazer with a 233 transfer case, 4.3 CPI, and push-button activated transfer case. My problem is that it won't engage into "4 high"...if I stop with the transmission in neutral, it will shift into "4 low" and work normally, but "4 high" won't work at all. The lights on the push button switch blink when activating into "4 low" but nothing into "4 high". Has anyone else had this problem? what causes it and what is the way to fix it? I have checked all fuses and think it might be something in the shift activation motor on the transfer case. Any help or comments would be greatly appreciated. Thanks, Murray
     
  2. schwinnd

    schwinnd 1/2 ton status

    Joined:
    Feb 26, 2001
    Posts:
    109
    Likes Received:
    0
    Location:
    SE Washington
    Re: 4 wheel drive won\'t engage on \'94 S10 4x4 w/233 transfer case

    Sorry I can't help you, but I have a '97 s10 blazer with the exact same problem. My dad has a '94 s10 pickup and guess what....same thing. These vehicles suck. There is a vacuum actuator switch located on top of the transfer case on the driverside. It cost about $28 from the chevy dealer and is pretty easy to replace, just a little tight. I replaced mine but it didn't help. What happens is you push the button an electronic signal actuates the vacuum switch which sucks in a diaphram under the battery which pulls a cable to engage the 4wd. It could be the switch, as described above, a collapsed rubber air line to the diaphram, or the diaphram itself. Good luck, sorry I can't help you more. If you figure it out let us know.

    Dave
     
  3. Jamus

    Jamus Registered Member

    Joined:
    Jan 10, 2002
    Posts:
    29
    Likes Received:
    0
    Location:
    Morgantown, WV
    Re: 4 wheel drive won\'t engage on \'94 S10 4x4 w/233 transfer case

    I think it might be the encoder motor. The 233 is controlled my a computer which has trouble codes like the engine computer. Use a jumper wire and go from terminals J and A on the ALDL under the driver's side dash. There's only 4 codes. The 4wd light will flash for each code.
    Code 1 = normal
    Code 2 = encoder fault
    Code 3 = TCCM motor circuit
    Code 4 =RAM/ROM failure
     
  4. Diesel Dan

    Diesel Dan 1/2 ton status

    Joined:
    Feb 27, 2002
    Posts:
    798
    Likes Received:
    0
    Location:
    Warren, Ohio
    Re: 4 wheel drive won\'t engage on \'94 S10 4x4 w/233 transfer case

    My '93 blazer does the exact same thing. It has a code 2 for the encoder stored. I replaced the encoder and it still wouldn't work. You need to pull the fuses or battery cable to clear the codes. After clearing codes system worked fine, for a while. Then code 2 came back and no 4HI. Pulled fuses again, worked, for a while. I think my case is a failing controller that is setting false codes. Lately cruising down the road after about 25 miles the green 4hi light will come on all by itself, press the switch and it goes out.
     
  5. Jamus

    Jamus Registered Member

    Joined:
    Jan 10, 2002
    Posts:
    29
    Likes Received:
    0
    Location:
    Morgantown, WV
    Re: 4 wheel drive won\'t engage on \'94 S10 4x4 w/233 transfer case

    All this info came from another board but I don't remember which one it was.

    To clear the codes, ignition off, pull the 5 amp TCCM fuse, wait at least 2.5 minutes, replace the fuse, then cycle the key on/off 5 times.

    This is what the service manual says for code 2.
    --------------------------------------------------------------------------------------
    -Disconnect transfer case electrical connector
    -Ignition in run
    -Measure voltage at pins 1(yel/blk), 2(dk blu/wht), 4(brn/wht), and 8(red/wht) - harness side
    -DVOM should read 5 volts (DC) at pins 1,2,4, and 8 - Does it?
    No--->Check for open or short to ground in circuits with 0 volts and repair, if circuits are ok, replace TCCM
    yes--->Measure resistance between transfer case (harness side) pin 3 and a good ground, should be less than 2 ohms. Is it?
    No--->repair circuit #1554 (blk/wht)
    Yes--->replace encoder motor
     
  6. Diesel Dan

    Diesel Dan 1/2 ton status

    Joined:
    Feb 27, 2002
    Posts:
    798
    Likes Received:
    0
    Location:
    Warren, Ohio
    Re: 4 wheel drive won\'t engage on \'94 S10 4x4 w/233 transfer case

    I have the diagnostic charts from the GM manual. It pointed to the encoder assembly on the t-case, but that was not the real problem.

    Was at a shop today picking up a new toy. They had several 233 equipped blazers for parts. I inquired about a controller for one and the guy told me that was not the problem.

    His story is as follows. The had sent a blazer to an electronics shop to be fixed, they had given up, no 4wd hi. It turned out to be a bad nuetral/saftey swicth giving a poor ground to the computer. Says they have fixed 3 blazers and 2 trucks with no 4HI with a new neutral safety switch. I looked at my schematic and sure enought, a ground runs thru that switch. I think I'll give that a shot, he wasn't even interested in selling me a contorller out of one of the trucks.
     
  7. s10350power

    s10350power Registered Member

    Joined:
    Aug 6, 2002
    Posts:
    16
    Likes Received:
    0
    Location:
    Maryland
    Re: 4 wheel drive won\'t engage on \'94 S10 4x4 w/233 transfer case

    Just goto 4wheelparts.com and but the posi lock system. its under the drivetrain selection on the side of the page.
     

Share This Page