4WD Error Codes

Is there an easy way to get 4wd (blink) error codes for my 4wd 98 blazer,

16 pin odb2?

Thanks. _________________________________________________________________ JG... Jeff Givens mailto: snipped-for-privacy@comcastXX.netXX

"My hovercraft is full of eels."

Reply to
Jeff Givens
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Ground pin 13.

Ian

Reply to
shiden_kai

Thanks Ian.

Are the procedures and codes the same as on the older aldl's?

Also, from some readings I seem to get that some encoder faults can be cleared and with a little luck restore encode motor operations. Are you familiar with this and would it apply to my problem?

Oh, the problem is 4wd won't engage in anything but neutral, and then only

4lo. When pressed the two 4wd button lights blink 5 or 6 times then go back to 2wd. No noises made. If in neutral, 4lo can be engaged (and the hubs are locking). No difference when the 4hi button is pressed - it goes back to 2wd.

So I guess it is an encoder problem, the solenoid and vacuum system works, only for 4lo though. _________________________________________________________________ JG... Jeff Givens mailto: snipped-for-privacy@comcastXX.netXX

"My hovercraft is full of eels."

Reply to
Jeff Givens

Usually, I do this as a very quick diagnostic method. When the encoder motor fails enough to set the "2" code, often the 4x4 system will not work until you fix the problem and clear the code. If the problem is simply an intermittent, but has still set the code, you can clear the codes, and if the

4x4 system starts working normally, you can rest assured that the encoder motor is faulty, and eventually it will fail again and set the code. So I will usually pull the vehicle in, check for codes, code 2 present, clear the codes, check operation, it all works, go get an encoder motor. Done.

Ian

Reply to
shiden_kai

I also read that if you get a code 4, then that means the PCM needs to be replaced...

Jason

Reply to
Jason Sobol

Thanks for all the information Ian. I am having trouble clearing the codes (am getting #2). I don't have a 'tccm' fuse to pull (98 Blazer), found the

10A one labeled "4wd". Pulled it, waited 20 minutes, reinserted the fuse, cycled from off to run 5 times, then started, no joy in getting 4HI to engage. 4LO can only be engaged in N.

I had just read something about a very similar problem being not the encoder motor itself but a neutral switch with an intermittent ground. Have you seen or heard of this possibility?

Thanks again. _________________________________________________________________ JG... Jeff Givens mailto: snipped-for-privacy@comcastXX.netXX

"My hovercraft is full of eels."

Reply to
Jeff Givens

Following myself:

Found another post of Ian's, says to use CTSY LP fuse.

Did this, faults cleared, 4wd working.

We'll see how long it lasts.

Thanks to everyone, especially Ian. _________________________________________________________________ JG... Jeff Givens mailto: snipped-for-privacy@comcastXX.netXX

"My hovercraft is full of eels."

Reply to
Jeff Givens

Yeah, it's wierd...even the GM manuals can be out to lunch on this procedure. Glad you managed to clear the codes. Obviously if it comes back, time for an encoder motor.

Ian

Reply to
shiden_kai

Are you saying that your Blazer still has a vacuum system for the 4X4? I thought that with the encoder motor they don't use vacuum.

I have a 1999 GMC Jimmy that is giving me problems not engaging into 4X4 = it has the Auto 4 wheel drive button. The dealer said that most times they = have to open the front differential and replace goodies in there. I was not = too keen on that idea not at $700 - $1200

So, what could be the problem?

1997 SFA 60920 1998,1999,2000,2001,2002,2003 AMA 602785 Due to E-Mail spamming bots my reply address is incorrect. Add a "-" between mr and wizard This is what we have to do to prevent "Spamming?" Sucks doesn't it?
Reply to
Kurt

Kurt said

Don't overlook the possibility of it being just the switch module itself - about $35 from gmpartsdirect.

In your case, does the 4Hi light ever illuminate? In my case (99 Silverado) the 4Hi would flash, but never go solid, and return to 2Hi.

Casey

Reply to
Casey

I read all the other responses, I won't forget that the switch module = could be the culprit. The 4Hi light would at most times just flash, if I cycled = back to 2Hi & 4 Hi a few times, it would lock up & stay lit.

The worst problem is if I use Auto 4X4 it could lock up one time but then= the next time you get into the pedal in the snow & need it, it will = flash & won't lock up. Very dangerous!

1997 SFA 60920 1998,1999,2000,2001,2002,2003 AMA 602785 Due to E-Mail spamming bots my reply address is incorrect. Add a "-" between mr and wizard This is what we have to do to prevent "Spamming?" Sucks doesn't it?
Reply to
Kurt

My 2001 Blazer would't come out of 4 wheel dr.I had to put in in neutral before button would work allowing it to go into 2 wheel drive. My problem now is it wont go into 4 wheel drive anymore. Could it be the module? It just flashes when you push it.

I have a 1999 GMC Jimmy that is giving me problems not engaging into 4X4 it has the Auto 4 wheel drive button. The dealer said that most times they have to open the front differential and replace goodies in there. I was not too keen on that idea not at $700 - $1200

So, what could be the problem?

1997 SFA 60920 1998,1999,2000,2001,2002,2003 AMA 602785 Due to E-Mail spamming bots my reply address is incorrect. Add a "-" between mr and wizard This is what we have to do to prevent "Spamming?" Sucks doesn't it?
Reply to
JohnnyD

Ian, guess what?

Hah, no, no fault code or failure to engage. Well, sort of.

It isn't putting any power to the front. The hubs are locking but no power. I guess I'll put it up on jacks and see if the xfer case is also engaged but I doubt I will find so. I hadn't done this before, I just checked the front drive shaft to be sure it was not free spinning. Now in winter conditions it is obvious nothing is happening up front.

What in your experience could this be? Of course I had the encoder fault before, but none now. Possibly a wiring thing; connectors, switches, etc., or the motor itself despite the lack of a fault this time? _________________________________________________________________ JG... Jeff Givens mailto: snipped-for-privacy@comcastXX.netXX

"My hovercraft is full of eels."

Reply to
Jeff Givens

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