Mechanics

CHEVY TRANSFER CASE GOING IN NEUTRAL

2003 Chevrolet Silverado

Transmission problem
2003 Chevy Silverado V8 Four Wheel Drive Automatic 130000 miles

I have just replaced the transfer case and the transfer case module on this truck. The Transfer case is from a used lot and the transfer module is remanufactured. The problem is that when I'm driving the truck and stop or let off the gas, on four occasions within the last month, it has been like the truck was in neutral. It was still in gear, but the transmissin is not engaging and acting as if it's shifted into neutral. It's not though. The way I have corrected it is to hit the Autoselect 4WD button or the 4HI button. Immediatly, you an feel the transfer case engage and it corrects the problem. I can then shift it back to 2Hi and it works as it should. What is causing this problem.
In addition to that, today, it's raining, it did it twice today with me correcting it with the button mashing I just described. I don't know if it's related to it or not, but today, I am having problems with my wipers not turning off. You can put them on intermittent and that worked for awhile. However, when I go to turn them off, they don't turn off. They will work if shifted to high speed and back to low speed, but not intermitent and they will not turn off when placed in the off position. What's going on with this? IS it related to the tranny problem too?
Avatar
Jrr5471
March 10, 2010.




As far as the transfer case is concerned, when the neutral condition occurs, does the indicator show neutral? To electronically shift into neutral requires simultaneously pressing 2hi and 4lo. This specific resistance value(or volt drop) is interpreted by the module, and corresponds to the selected range output. Is this what the transfer case and module were replaced in attempt to correct? What do the switch indicators do when this happens? I am not certain what would happen, but if you are selected in 2hi, and you disconnect the encoder on the case, would it stay in 2hi. If that is the case, it may be worth a try to see if the problem is still reproduced. If so, I would say you have something going on in the case(mechanical). You may have some corresponding service 4WD indicator, and some codes set, but you should still be able to operate it, and the codes would clear when normal operation is resumed. Otherwise, you may need a scan tool that would communicate with the ATC module, and check to see if inputs are telling it to go into neutral.
As far as the wipers are concerned, I don't see how they would be related to the transfer case. So you have high speed, lo speed respectively, but no intermittent? When the switch is in intermittent, do the wipers just stop anywhere on the windshield, or do they continue on lo speed with no pulse? My first guess would be a wiper module that has the switch signal shorted to voltage internally, It could also be a switch. I will forward you the diagnostic chart for wipers always on.

Wipers Always On
Step
Action
Yes
No

Schematic Reference: Wiper/Washer Schematics

Connector End View Reference: Wiper/Washer Connector End Views Lighting Systems Connector End Views

DEFINITION: Windshield wipers are always ON at low or high speed.

1
Did you review the Wiper/Washer System Description and Operation and perform the necessary inspections?
Go to Step 2
Go to Symptoms - Wiper/Washer Systems

2
Turn the windshield wiper/washer switch OFF.
Turn the ignition ON, with the engine OFF.
Are the windshield wipers always on?
Go to Step 3
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3
Turn the ignition OFF.
Disconnect the turn signal multifunction switch connector C3.
Turn the ignition ON, with the engine OFF.
Are the windshield wipers always on?
Go to Step 4
Go to Step 7

4
Are the windshield wipers always ON at high speed?
Go to Step 5
Go to Step 6

5
Test the windshield wiper switch high signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 11
Go to Step 9

6
Test the windshield wiper switch signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 11
Go to Step 9

7
Inspect for poor connections at the windshield wiper/washer switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 11
Go to Step 8

8
Replace the windshield wiper/washer switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.

Did you complete the replacement?
Go to Step 11
--

9
Inspect for poor connections at the windshield wiper motor module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 11
Go to Step 10

10
Replace the windshield wiper motor module. Refer to Windshield Wiper Motor Replacement.

Did you complete the replacement?
Go to Step 11
--

11
Operate the system in order to verify the repair.

Did you correct the condition?
System OK
Go to Step 3

Factoryjack
Mar 11, 2010.


AD