4WD diagnosis; pics. Help.

[Schrade]

Mine is broken. Let's see if I can break it more... '98 Jimmy. If I re-set the computer, it works perfect, one time, then goes into error mode, with NO SES light (unless it's broken. does it light up when you turn on the key?)

Problem: dash module lights blink, light up wrong, or blink then out.

Battery out...

When I unplugged this vac line, it was holding vacuum.

I'm listenin' here for tips...

[MT-2500]

Originally Posted by cbec1999

Mine is broken. Let's see if I can break it more... '98 Jimmy. If I re-set the computer, it works perfect, one time, then goes into error mode, with NO SES light (unless it's broken. does it light up when you turn on the key?)

Problem: dash module lights blink, light up wrong, or blink then out.

Battery out...

When I unplugged this vac line, it was holding vacuum.

I'm listenin' here for tips...

What transfer case?
Have you checked for transfer case codes?

[MT-2500]

233 you have to ground pin 13 on diagnostic connector to read codes on transfer case shift button lights.

[Schrade]

Originally Posted by MT-2500

233 you have to ground pin 13 on diagnostic connector to read codes on transfer case shift button lights.

Had to break - dark cold (too much global warming).

Too late to check codes - battery's out, unless they store in CCM, not PCM? I didn't even know you could jump OBDII

I don't know what transfer case... '98 Jimmy v6 auto - does that tell?

edit: 233? NP233 TC?
Code lights lite up same as OBDI? 34 = flash-flash-flash pause flash-flash-flash-flash
Which ground pin? #4?, 5?

[old_master]

Does the vacuum actuator hold vacuum?
Does the actuator pull the cable when you apply vacuum to the actuator?

[Schrade]

Originally Posted by old_master

Does the vacuum actuator hold vacuum?
Does the actuator pull the cable when you apply vacuum to the actuator?

I said in post 1 that the vacuum line (in the pic) had vacuum when I pulled it off. Is there a different vacuum line in the actuator system that you're asking about?

The cable was retracted about 3/4" from the vacuum in the line (in the pic). You can see it a little in the third pic how far it's drawn. Should it draw further than that? Or are you asking about another component in the system?

[MT-2500]

Originally Posted by cbec1999

Had to break - dark cold (too much global warming).

Too late to check codes - battery's out, unless they store in CCM, not PCM? I didn't even know you could jump OBDII

I don't know what transfer case... '98 Jimmy v6 auto - does that tell?

edit: 233? NP233 TC?
Code lights lite up same as OBDI? 34 = flash-flash-flash pause flash-flash-flash-flash
Which ground pin? #4?, 5?

Transfer case id is on back of transfer case.
Pin ID
http://www.troublecodes.net/OBD2/

98 OBD11 uses 4 digit codes for engine and transmission.

Grounding pin 13 gives transfer case codes 1 threw 4 on transfer case push buttons.


If battery has been unpluged you will have to hook it back up and drive and the shift transfer case and then read codes.

What lights come on key on and then after you drive it and try to shift it?
What light are you getting 3 and 4 codes?

[Schrade]

Alright - put the battery back, and set codes again.

Does it have to go closed loop to set tranny/TC codes?

[MT-2500]

Originally Posted by cbec1999

Alright - put the battery back, and set codes again.

Does it have to go closed loop to set tranny/TC codes?

No .
It should set code when it does not shift into and out of 4W.

Watch the shift button lights and tell us what they are doing.
And check for and post back transfer case codes.

[Schrade]

Battery back in, computer cleared, and function perfect one time, as it always does after computer is cleared, till I got out of the driveway, and shifted it again. Then failure mode again. No SES lights or anything.

Drive around the block til closed loop, and stick in the super-duper high-tech .10 cent scanner, sockets 4 and 13. The clip doesn't show up too good. Guess I need the EXTRA super-duper model.

No codes flashed in the shifter lights, just 1-2, repeated. This means the computer is reading as it should.

No codes. ???

Help?

1 threw 4 on transfer case push buttons.

What do you mean by this?

[MT-2500]

Code 1 is lose of ram stand by power.

Code 2 is encoder motor or encode motor to TCCM circuit fault.

[Schrade]

Originally Posted by MT-2500

Code 1 is lose of ram stand by power.

Code 2 is encoder motor or encode motor to TCCM circuit fault.

Do you have schematics? Or FSM diagnostic procedure?

[MT-2500]

Originally Posted by cbec1999

Do you have schematics? Or FSM diagnostic procedure?

Sorry.
Most of my repair info is copy righted.
And can not be posted online.
For repair flow charts and wiring diagrams.
A factory repair manual or.
http://www.alldata.com/products/diy/index.html

Public libraries also have care repair info and most are online.

[Schrade]

Originally Posted by MT-2500

Sorry.
Most of my repair info is copy righted.
And can not be posted online.
For repair flow charts and wiring diagrams.
A factory repair manual or.
http://www.alldata.com/products/diy/index.html

Public libraries also have care repair info and most are online.

Copyrighted. That means you can't SELL the info. You CAN give it away, like I do here. Same as the music and videos that you download and don't re-sell, but share.

No problem... Here's some stuff posted elsewhere online Rockland Standard Gear INC. No fear @ rsgear I'll refer as I go along...

Public libraries have squat. Chilton's, Hayne's, Clymer's. Stuff that should have a round hollow binder, and hang in the 'library'.

Tear a page, read, wipe, flush, repeat. Crinkle if you're tender in the hindparts .

[MT-2500]

Forum rules will not let me post coptrighted stuff.
Done had my rear end chewed one time.
But
That Rochland link has good repair info.
Let us know how it goes.