Another service 4wd quandary

[Cooked]

Ladies and gentlemen

First let me start off by saying that I have tried to avoid this post by searching this site, as well as many others for my answer first with no luck yet.

I have a 2005 chevy silverado 1500 with a 5.3L in it.

I had a service 4wd message come up about 2 years ago and searching this site helped me to buy and replace the encoder motor sensor with complete resolution of 4wd problems.

So 2 months ago, service 4wd light. Bought the encoder motor sensor, thought I would remember the repair. As I swapped the sensor out I rotated the motor shaft. Tried to fit it back together feeling stupid. Hooked it all back up. Service 4wd light.

 

So, I've now replaced the entire encoder motor with a new unit, as well as replaced the dash 4wd selector. thinking that might be the problem with no luck.

Hoping that you guys might have some insight. I'm thinking that when I rotated the motor without the sensor and then had to turn the actual transfer case selector gear to match up, it messed it up.

Thanks so much for your help!

[gmtech4]

not once have you mentioned what code you pulled from the TCCM,

 

get is scanned is the very first thing ya do ,,,,not throw parts at it

 

oh ,welcome to the site

[Cooked]

Rob

Thanks for the quick reply. Does it have to be taken to a dealership to scan it or can any autozone/advance scan something like that?

 

Thanks

 

Doug

[gmtech4]

not sure ,any garage will have a scanner that can pull them ,,,,,,you can try ,IDK ,they can only access some moduale s.,..someone here will chime in for sure

[Cooked]

Alright, I took the truck to a dealership today to have them pull the codes from the transmission. Neither autozone nor O'reilly's was able to access the trouble codes from the transfer case.

The dealership pulled the C0321 code. Transfer case lock circuit malfunction.

Any ideas or help would be greatly appreciated!

 

Thanks!

Doug

[gmtech4]

DTC C0321

Circuit Description

The transfer case shift control module controls the transfer case lock
solenoid.

The transfer case lock solenoid is released by being energized. This is
accomplished by grounding the lock solenoid control circuit during gears shifts,
and in the AUTO 4WD mode. Locking action is applied when power or ground are
taken away from the lock solenoid, the transfer case motor is prevented from
moving. The system is capable of providing a 2HI, 4HI and 4LO lock-up without
the need of additional vehicle power to hold the transfer case in these
positions.

This DTC detects an open lock solenoid coil, open motor lock control circuit,
or an open motor lock feed circuit.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0321 Transfer Case Lock Circuit Malfunction

Conditions for Running the
DTC

• The ignition is ON.
• 
  
• The system voltage is 9–18 volts.

Conditions for Setting the
DTC

• The transfer case shift control module tries to unapply, turn OFF the lock
  solenoid by grounding the motor control circuit.
• 
  
• If the module does not sense the battery voltage at the motor lock control
  circuit prior to applying the motor lock, the DTC sets.
• 
  
• Transfer Case Lock output reads back as a high voltage when a low voltage is
  expected.

Action Taken When the DTC
Sets

• All shifting is disabled.
• 
  
• The SERVICE 4WD indicator remains illuminated for the remainder of the
  current ignition cycle.

Conditions for Clearing the
DTC

• The transfer case shift control module will clear the DTC if the condition
  for setting the DTC is not currently present.
• 
  
• A history DTC will clear after 100 consecutive ignition cycles without a
  fault present.
• 
  
• History DTCs can be cleared using a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. • Listen for an audible click when the encoder motor brake operates.
     Command both the ON and OFF states. Repeat the commands as necessary.
   
   
   • This step tests for voltage at the lock solenoid feed side of the
     encoder motor lock solenoid.
   
   
   • This step verifies that the lock solenoid battery positive circuit
     is not shorted to power, shorted to ground, or have high resistance.
   
   
   • This step determines if the encoder motor lock solenoid is faulty by
     checking the internal resistance.
   
   
   • This step tests the encoder motor brake solenoid for an internal
     short to ground.
   
   
   • This step tests the control circuit of the encoder motor brake for a
     short to voltage or an open.
   
   
   • This step determines if a corroded or damaged connector in the
     encoder motor harness is the cause.

DTC C0321

Step

Action

Values

Yes

No

Schematic Reference: Transfer Case
Control Schematics

Connector End View Reference: Transfer Case
Control Connector End Views

1

Did you perform the Diagnostic System Check – Vehicle?

—

Go to Step 2

Go to Diagnostic
System Check - Vehicle in Vehicle DTC Information

2

2. Install a scan tool.
3. 
   
4. Turn the ignition ON, with the engine OFF.
5. 
   
6. Apply the Park brake and put the transmission in Neutral.
7. 
   
8. With the scan tool, command the transfer case lock control
   ON and OFF.

Do you hear the encoder motor lock click when turned ON and OFF with each
command?

—

Go to Testing for
Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

2. Turn the ignition ON with the engine OFF.
3. 
   
4. Using a DMM, measure the battery positive voltage circuit of
   the transfer case lock solenoid.

Is the voltage within the specified range?

12.5–14.5 V

Go to Step 5

Go to Step 4

4

Inspect the lock solenoid battery positive circuit for an open, a short to
ground, or a high resistance. Refer to Circuit
Testing and Wiring
Repairs in Wiring Systems.

Did you find and correct the condition?

—

Go to Step 10

Go to Step 5

5

2. Disconnect the transfer case encoder motor connector.
3. 
   
4. Check the internal resistance of the lock
   solenoid.

Is the resistance within the specified values?

15–25 Ω

Go to Step 6

Go to Step 9

6

At the encoder motor pigtail check the 8 lock solenoid windings for an
internal short to ground, by probing the lock solenoid control with a DMM and
taking the other lead to ground.

Did the DMM indicate a short to ground?

—

Go to Step 9

Go to Step 7

7

2. Disconnect the transfer case shift control module.
3. 
   
4. With a DMM, test the lock solenoid control circuit for a
   short to ground, a short to voltage or a high resistance.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 8

8

Check all connectors for corrosion or damage. Refer to Connector
Repairs in Wiring Systems.

Did you find and correct the condition?

—

Go to Step 11

Go to Step 10

9

Replace the encoder motor. Refer to Transfer Case
Encoder Motor Replacement.

Did you complete the repair?

—

Go to Step 11

—

10

Replace the transfer case shift control module. Refer to Control Module
References in Computer/Integrating Systems for replacement, setup, and
programming.

Did you complete the repair?

—

Go to Step 11

—

11

2. Use the scan tool in order to clear the DTCs.
3. 
   
4. Operate the vehicle within the Conditions for Running the
   DTC as specified in the supporting text.

Does the DTC set?

[gmtech4]

if ya dont have a scanner or electrical experience you will have to pay someone to diagnose it for you .

 

good luck