[brubakes]

What are all the sensors that can trigger the "SERVICE 4WD SYSTEM" error message? I do NOT have the Quadra-Trac II system if there are additional sensors specific to it.

 

[Scottina06]

they run along the suspension and plug into the hubs

 

[brubakes]

they run along the suspension and plug into the hubs

One per wheel? ABS sensors in the same place?

 

[Scottina06]

yes...same thing. The abs sensors also serve as the awd system sensors sort of

 

[brubakes]

yes...same thing. The abs sensors also serve as the awd system sensors sort of

Maybe that's why I couldn't find part numbers for the 4WD sensors. Guess I'll start looking at/for the ABS sensors.

 

[Scottina06]

they are like $32 each or so. Run along the knuckle and plug into hub. Very easy replacement.

 

[brubakes]

Is this what I'm looking for? The right rear looks pretty tight compared to the other side.

 

[Scottina06]

which one do you need to replace?

 

[brubakes]

which one do you need to replace?

The right rear looks like it's been pulled tight so maybe that one. Truth is I don't know, but if the sensor is only $13 for each rear or even $30 for each front just throwing parts would be cheaper then taking it to the dealer.

 

[Scottina06]

Or find someone who has a code reader. Local garage, body shop etc.

 

[brubakes]

Or find someone who has a code reader. Local garage, body shop etc.

please correct me if I'm wrong, but don't you need the special dealer only star scan tool for the four wheel drive and ABS system codes?

 

[brentwoodkris]

please correct me if I'm wrong, but don't you need the special dealer only star scan tool for the four wheel drive and ABS system codes?

If you're getting the Service 4WD message, you can probably do the key flick trick and get the DTC to display the code. That should at least let you identify L or R side. Without the StarScan or a tuner there is no way to differentiate between F/R. However, someone posted that you could measure the resistance of the sensors if you pulled them to tell whether they're still good or not.

 

[brubakes]

If you're getting the Service 4WD message, you can probably do the key flick trick and get the DTC to display the code. That should at least let you identify L or R side. Without the StarScan or a tuner there is no way to differentiate between F/R. However, someone posted that you could measure the resistance of the sensors if you pulled them to tell whether they're still good or not.

Tried then found out the '08 doesn't offer the key dance.

 

[brentwoodkris]

Tried then found out the '08 doesn't offer the key dance.

Ouch. I forgot they removed cool features like that and also being able to reset your service intervals, etc in the later years.

 

[brubakes]

Ouch. I forgot they removed cool features like that and also being able to reset your service intervals, etc in the later years.

I know right! Especially when it was already there, so resources had to be used to engineer that out of the system.

 

[Jeepforthewin]

please correct me if I'm wrong, but don't you need the special dealer only star scan tool for the four wheel drive and ABS system codes?

You don't need star scan for speed wheel sensors. I've had mine scanned twice to pinpoint which one was at fault and both replaced and good to go

 

[brubakes]

You don't need star scan for speed wheel sensors. I've had mine scanned twice to pinpoint which one was at fault and both replaced and good to go

So if a normal CEL scanner doesn't pick it up then safe to assume those wheel sensors are okay?

 

[brentwoodkris]

You don't need star scan for speed wheel sensors. I've had mine scanned twice to pinpoint which one was at fault and both replaced and good to go

I don't think this is true, unless perhaps the CEL scanner you have picks up ABS codes. The newer ones can do this, but IMHO, most people don't have those (they're more expensive and newer).

So if a normal CEL scanner doesn't pick it up then safe to assume those wheel sensors are okay?

Like I said above, if your ABS light is on and you have a CEL scanner that reads ABS codes, it possible that you might get a code that tells you which sensor is out of whack.

However, if you've just got the Service 4WD message, then no CEL scanner is going to give you any more info than you already have.

 

[Drock970]

I replaced all 4 of my wheel speed sensor with no luck with the 4WD light. I then read a ton of threads and found it was more then likely the wire harness for the solenoid on the inside of the front or rear diff.

-Hop under your jeep to the rear diff.
-At the top there is one wire connection and only one disconnect it.
-Throw some test leads on the sensors 2 male pins and make sure your reading 14 ohms.
-If you read 0 then your wire harness on the inside of the diff to the solenoid actuator is busted.

My front diff solenoid read 0 ohms. Cracked the front diff cover and found the wire harness was completely broke. Replaced the harness $10 part from stealership and Service 4WD light went off instantly . Hope this helps The pic is the harness that sticks out the top of the diff. You can see the two wires that go into the inside of the diff an connect to the solenoid are completely cut off.

 

[brentwoodkris]

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