2003 awd issues

[AUTO-MAN]

the AWD doesn't work in my 2003 safari (140km's). Sent it to a shop and they said everything mechanical is good, proper fluid, clutches good, the front sensors ok, the encoder motor operates as it should. he said there was no power getting to the encoder motor(he also said he was no good at electrical). I pulled and greased all connectors at the TC but they were clean. I have no service AWD light and definitely no front wheel power. Today with KOEO i pulled the ATC fuse and could hear my TCCM clicking, and again when I put it back. no codes at all. All my fuses are good. The service AWD light comes on and goes out when you start the van
To summarize, I have no service AWD light and no AWD. I searched the net for a week and all i found had to do with the service AWD light being on.
Any help?

[Herbie]

I'm curious how mechanic diagnosed the transfer case as mechanically good if there was no power getting to the encoder motor? Also, did you hear the TCCM clicking, or the motor clicking? (The TCCM is the electronic control module - it shouldn't be clicking, so far as I know.) And if you're referring to the motor, just clicking alone isn't sufficient for diagnosis, since it may be clicking but not fully engaging (which would explain your lack of AWD and also why you don't have any warning lights - if it responds correctly but doesn't fully engage)

IIRC, there's a diagnostic procedure in the Factory manual that includes using a meter to check for a set of signals on the connector. It's fairly straightforward, so that's where I'd start. After that, I think there's a separate procedure for confirming encoder motor operation.

[Mmusicman]

I'm curious how mechanic diagnosed the transfer case as mechanically good if there was no power getting to the encoder motor?...

^^ EXACTLY! And it's not likely they removed, and tore the transfer case apart, to tell you the clutches were good?

[AUTO-MAN]

I cannot question the tech or answer for him at this time, but I will. The van has less than 90,000 miles. The fluid was like new and had no metal or smell.
The fuse that I pulled was the ATC fuse under the hood. The single clicking sound came from behind the ebrake. Clicked 1 time when I pulled it, waited 30 seconds, 1click when I replaced it. The light did not come on while the fuse was out. It never makes a noise at any other time.
.thanks for any help!

[Mmusicman]

Couple things should be noted:

* Yes, pulling the fuse also disables the "Service AWD" light, and disables everything.
* The power (signal) to energize the encoder motor is ONLY activated when front and rear prop shafts turn at different speeds. Otherwise, there is no power (signal) to encoder. How was this simulated for testing?
* The signal going to encoder is PWM (pulse width modulated) and may be tricky to read with typical VOM (volt meter).

If the encoder is not getting a signal, then the transfer case itself, fluids, clutches, etc are most likely not to blame... since it will never be engaged in the first place. Judging from what you are saying (if accurate) it sounds like the controller itself may be to blame if it is not sending a signal. But the question would by.. why? But bear in mind, the controller needs signals from both speed sensors as well, to activate the AWD encoder. I would ensure that they are connected properly as well. I'm not sure if, or how, they can be tested if all else is good.

[AUTO-MAN]

The tech stated he checked both front wheel sensors and they were good.

[AUTO-MAN]

the van did have a ABS light on when I purchased it. After reading what the net had to offer I figured repairing the issue would make the AWD work but no luck.

[Mmusicman]

The tech stated he checked both front wheel sensors and they were good.

Actually, the sensors are in the transfer case (not wheels sensors) ... one for the front shaft and one for the rear.

[AUTO-MAN]

If any of the sensors were bad would it not toss the light?

[AUTO-MAN]

Allrighty then...another diagnostic fee with no definitive answers.
When the van is in the air all the wheels turn. On the ground the scanner the encoder motor climbs to 100% but no torque to the front.

This shop said the fluid had a very slight burnt smell. code c0374, general system malfunction transfer case. They said it could be the encoder or the clutches but leaned towards the clutches because of the "normal" readings from the encoder.
Still no STC light

[Mmusicman]

When the van is in the air all the wheels turn. On the ground the scanner the encoder motor climbs to 100% but no torque to the front...

I have discovered when my AWD is in the air... all 4 wheels turn as well, even with the controller disconnected!
I think this is simply due to "stiction" (internal friction) .. and nothing else. There is no actual torque being applied until encoder is engaged.

For this reason, the "in the air test" is completely invalid... since it neither shows if the encoder is engaging, or if the clutches are actually working properly.