'03 ZR5 won't shift into 4 hi
Moderator: F9K9
'03 ZR5 won't shift into 4 hi
Basically it wont shift into 4 hi, no lights blink or anything. I did get it to switch once but i had it in neutral, an switched from 4 lo to 4 hi. (most of the time the 4hi &4lo lights blink and it goes back to 2 hi) Also when going into or out of 4 lo, the front end clunks, i think it is the hubs, but not sure. I'm not even sure if its related. Just looking for some suggestions on what the problem could be. Any help would be awesome.
Straight from the service manual:
The transer case encoder motor is an assembly which houses 4 separate channels. These channels are used to indicate to the transfer case shift control module the present gear position of the transfer case or if the tranfer case is in transition between gears. The encoder motor assembly consists of an electonically conductive inner ground ring in contact with a 3 legged wiper arm. Each legs length is such that it makes contact with the conductive regions of the 4 channels. When any leg of the wiper arm is making contact with the conductive area of any channel, the encoder provides a path to ground to the inner ground ring.
During electronic shifting, the transfer case shift control module monitors the transfer case encoder circuit for the proper operating sequence. If at any time during a shift, the encoder changes from one position to any position other than the next possible position, an error counter in the transfer case shift contol module increments by 4. After the counter reaches 32, the transfer case shift control module set a DTC2, a permanent "encoder fault," and reverts to a 2HI to 4LO or a 4LO to 2HI shift pattern only. To guard against a transient, random encoder fault due to vibration, dirt electrical noise, ect., the fault counter reduces by one each time the transfer case shift control module detects a valid encoder value. The encoder must intermittently fail 25 percent of the time for the transfer case shift control module to consider it faulty and store DTC2. It is imperative that the technician test-drive the vehicle and request several shift in order for the code to properly be set.
I had to read it several times before I understood it.
It sounds like you have a bad transfer case encoder motor. You may be able to clear the codes and have it working again but it will probably set the code again.
Pull the CTSY LP fuse to clear the codes.
Hope this helps.
James
The transer case encoder motor is an assembly which houses 4 separate channels. These channels are used to indicate to the transfer case shift control module the present gear position of the transfer case or if the tranfer case is in transition between gears. The encoder motor assembly consists of an electonically conductive inner ground ring in contact with a 3 legged wiper arm. Each legs length is such that it makes contact with the conductive regions of the 4 channels. When any leg of the wiper arm is making contact with the conductive area of any channel, the encoder provides a path to ground to the inner ground ring.
During electronic shifting, the transfer case shift control module monitors the transfer case encoder circuit for the proper operating sequence. If at any time during a shift, the encoder changes from one position to any position other than the next possible position, an error counter in the transfer case shift contol module increments by 4. After the counter reaches 32, the transfer case shift control module set a DTC2, a permanent "encoder fault," and reverts to a 2HI to 4LO or a 4LO to 2HI shift pattern only. To guard against a transient, random encoder fault due to vibration, dirt electrical noise, ect., the fault counter reduces by one each time the transfer case shift control module detects a valid encoder value. The encoder must intermittently fail 25 percent of the time for the transfer case shift control module to consider it faulty and store DTC2. It is imperative that the technician test-drive the vehicle and request several shift in order for the code to properly be set.
I had to read it several times before I understood it.
It sounds like you have a bad transfer case encoder motor. You may be able to clear the codes and have it working again but it will probably set the code again.
Pull the CTSY LP fuse to clear the codes.
Hope this helps.
James
2001 S10 Crew (wife's mail truck)
2002 S10 Crew, 2003 S10 Blazer
2006 K2500 5 speed
2002 S10 Crew, 2003 S10 Blazer
2006 K2500 5 speed
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HenryJ
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Start by inspecting the transfercase vacuum switch. There is a sticky on that. Then inspect the front axle actuator. Frozen cables and damaged actuators are common.
Next detach the battery cables (both), wait 3 minutes and re attach to reset the modules. Then see if things work.
Let us know after all that is done and we will go further if needed.
Next detach the battery cables (both), wait 3 minutes and re attach to reset the modules. Then see if things work.
Let us know after all that is done and we will go further if needed.
"Speed doesn't kill, suddenly becoming stationary does." - Richard Hammond
"Speed is just a matter of Money - How fast do YOU want to go?"-Mechanic from Mad Max-
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green02crew
- Crew Elite
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- Joined: Mon Nov 12, 2007 7:56 pm
- Location: Northern NH
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Any luck? because I have had a very similar problem recently...
Transfercase Codes
Check recent posts at the bottom...
I can never be done working on this truck! Whether its fun or fix!
Transfercase Codes
Check recent posts at the bottom...
I can never be done working on this truck! Whether its fun or fix!
2002 S-10 Crew Cab
Too Many Mods Check the Readers Rides Page
Too Many Mods Check the Readers Rides Page