Control Trac and New Tires

[ehepner]

I've got a '98 Sport w/ Control Trac. I recently put brand new tires on, did not change the tire size at all. What I did, b/c of not having $500 to drop on 4 tires was put front on then 700 miles and a paycheck later, put rear on. Same time as the rears, I had 4 new shocks and rotors and pads done all the way around. (same day, different shops, brake place doesn't do tires, tire place doesn't do brakes). Anyway, as soon as I left the tire shop I noticed my 4wl Hi/4 Wl Lo lights blinking. Could the short delay between front and rear tires have caused this? Would rotating tires help or hurt? Am I hurting anything by driving it?

 

[CDW6212R]

Used tires are a different diameter from new tires. The worry would be when the first pair was changed. Are they all the same size now(not tire size, actual diameter)? Have you used the 4WD before, or occasionally? Unused 4WD's can have issues from not being used.

If there are no other symptoms, I would disconnect the battery for several minutes, and try it from scratch. Good luck,

 

[ehepner]

I haven't measured them to see if they are, but they are the same brand/model front & rear now. I've used the 4wd some, but not extensively--it's a highway truck only.

Thanks for the quick reply

 

[CDW6212R]

If the 4WD has been used once or twice a year, even just occasionally in a straight line, it should work when needed. Is the mileage on the tires about the same?
A light should come on if the tires are too different in diameter, which is why I asked.

 

[ehepner]

There's about 700 miles difference between the 2 sets, all highway/decent city streets.

Thanks again,

Eric

 

[CDW6212R]

That's good, that's nothing. If you do not have any other symptoms concerning the 4WD, pull a battery cable for a short while, and then drive it to test it. If it lights up again, it will not be about tire diameters. Good luck,

 

[Glacier991]

The AWD control trac might be bothered by a disparity. I'd be curious to know what the codes are, and clear them and see what gives. I doubt you have daqmaged the viscous coupler.

 

[ehepner]

I had the autozone guy pull codes from the obd port, but all his scanner got were engine codes (seems I need an MAF sensor as well, but it's still running, so I'll save my $150 for something safety related like brakes and tires). I just bit the bullet and disconnected the battery--I've got the infamous blank radio display as well so I lost all my presets w/o anyway of resetting them until I get time to do the fix posted elsewhere.

 

[CDW6212R]

Interesting, the display power board must also feed the preset memories. My memories haven't been lost even with the unit out of the truck. That's about a $60 repair at good radio shops.

Hey Chris, how have you been?
FYI, the Control Trac is a 4WD system, not AWD, there is no viscous coupler in it.

You might do well to carefully clean the MAF sensor, and throttle body. Remove the MAF and use only a proper cleaner, like throttle body cleaner spray, or an electrical contact spray. Good luck,

 

[Glacier991]

Hi Don. I'm good thanks. I wrongly assumed the control trac came in the A4WD flavor AND the AWD.... I see I was mistaken. I'm intiomately familiar with the Control Trac A4WD assembly... will have to go back and re-read my own into about the GEM and operation to see why it might throw a code.

I am wondering if this code is a proporietary code and that is why it won't read.

 

[gijoecam]

It's a GEM code. You'll need an NGS tester (or equivalent) to read the codes to tell you exactly what the GEM was detecting wrong with the system. The tires may have just bee an coincidence with a bad speed sensor. Without knowing what specific code it threw, it's a guessing game at best.

-Joe