2002 4

MRSNILLOC

MEMBER
2002 CHEVROLET S-10
100,000 MILES

2002 4.5 liter s-10 pick up wont go in 4hi. 4 wheel drive push button on the dash. Put truck in neutral and it will go in 4 lo. Vacuum actuator under battery tray is working when button is pushed. Can hear actuator on transfer case clicking when button is pushed for 4 lo but does nothing for 4 hi. Disconnect the battery and truck will go into 4 hi, 4 lo, everything works fine for awhile then back to not working! Installed another module behind kick panel from junk yard, with no diff results execpt everything works fine for awhile like disconneting battery. Any hep would be appreciated. Thanks in advance!

5 Replies

HMAC300

MECHANIC
48,601 POSTS

Check the tcase actuator, it's probably not working

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Monday, November 5th, 2012 AT 3:26 PM

MRSNILLOC

MEMBER
3 POSTS

So it could be something wrong with the transfer case actuator causing it not to go in 4hi even though it does work for 4lo and it all works if you disconnect the battery and reconnect it back?
Is it possible that it could be the Vacuum Actuator Switch that sits on the transfer case? Thanks again!

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Wednesday, November 7th, 2012 AT 5:45 PM

HMAC300

MECHANIC
48,601 POSTS

Ya it could be that or it could be the tcase module as well, you really need to scan this to see if a code is coming up which i'd bet is. To see where to look

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Wednesday, November 7th, 2012 AT 5:47 PM

MRSNILLOC

MEMBER
3 POSTS

My fault, I failed to mention that the truck has been scanned and there is no code coming up. Thats what I was told anyway. Kept the truck for 2 weeks with no results. Didnt charge me anything cause they didnt fix anything. Have had a local mechanic look at it and he cant come up with any good results either, hes the one that replaced the module behind the kick panel. He also checked the vacuum system and things look fine. Im really getting annoyed with this problem. Thanks

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Wednesday, November 7th, 2012 AT 6:01 PM

HMAC300

MECHANIC
48,601 POSTS

See if your courtesy lamp fuse is blown, if it is replace it then check for power at encoder motor. Both ways it may be sending power not giving a code but motor not working. They are about $100 to replace and I think you can get at an auto parts store. Try the chart i'm sending to see if that finds the problem but also check encoder motor.

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