code C03080

hoping for some help for a 2001 silverado 4x4. my service 4 wheel drive light is on and none of the lights are on in the switches. i have scanned and found code C0308, which has to do with the electric motor for the 4 wheel drive. can someone please tell me where the motor is located so that i can trouble shoot it. thanks inadvance pies.

Here's something for ya !

Good luck

DTC C0308
Circuit Description
The transfer case motor is a bi-directional, permanent magnet, D.C. motor. When energized, (through Motor Control A or Motor Control B, the ground is provided by the opposing motor control circuit and then grounded through the transfer case shift control module ground circuit), the motor, through a series of gears, rotates a shaft which moves the mode and range forks to shift the transfer case between 4H, 2H, N, and 4L ranges.

This DTC detects a short to ground in the motor control A or motor control B circuit.

Conditions for Setting the DTC
The system will test the motor circuits:
The system checks for unwanted voltage.
The system supplies voltage on one circuit and reads the voltage back on the other.
If the system detects a problem with the circuits, the DTC is logged.
The transfer case shift control module senses a low voltage return in Motor Control A or Motor Control B when a high voltage is expected.
Action Taken When the DTC Sets
All shifting will be disabled.
The SERVICE 4WD indicator lamp will be commanded on 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 no longer exists.
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 number(s) below refer to the step number(s) on the diagnostic table.

Listen for an audible motor noise when the transfer case encoder motor operates. Command both the ON and OFF states. Repeat the commands as necessary.

This step tests for a short to ground in the motor control A circuit.

This step tests for a short to ground in the motor control B circuit.

This step tests for a higher than normal resistance in the motor control A and B circuits through the module.

This step tests for a short to ground in the transfer case encoder motor windings.

This step tests for continuity across the motor circuit. Resistance readings vary depending on the location of the brush contact inside the motor assembly.

This step tests motor control A circuit for a short to ground.

This step tests motor control B circuit for a short to ground.

This step tests motor control A and B circuits for an open or high resistance.

Step
Action
Value(s)
Yes
No

Schematic Reference: Transfer Case Control Schematics

1
Was the Transfer Case Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check - Transfer Case

2
Start the vehicle.
Put the vehicle in NEUTRAL.
Using the transfer case control switches, attempt to shift through all modes and ranges.
Does the transfer case encoder motor turn ON and OFF?
--
Go to Testing for Intermittent and Poor Connections in Wiring Systems
Go to Step 3

3
Turn OFF the ignition.
Disconnect the four wire connector at the transfer case.
Connect a DMM between the motor control A circuit harness connector and ground at the transfer case.
Is the resistance reading less than the specified value?
10 K ohms
Go to Step 8
Go to Step 4

4
Connect a DMM between the motor control B circuit harness connector and ground at the transfer case.

Is the resistance reading less than the specified value?
10 K ohms
Go to Step 9
Go to Step 5

5
Connect a DMM between the motor control A and B circuit harness connector at the transfer case.

Is the resistance reading greater than the specified value?
2 ohms
Go to Step 10
Go to Step 6

6
Test terminals A and B at the transfer case side of the harness for a short to ground.

Was a problem found?
--
Go to Step 11
Go to Step 7

7
Test the resistance across the motor circuit.

Were the resistance readings within the specified range?
0.5-35 ohms
Go to Step 12
Go to Step 11

8
Disconnect the transfer case shift control module.
Test the motor control A 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 13
Go to Step 12

9
Disconnect the transfer case shift control module.
Test the motor control B circuit harness connector 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 13
Go to Step 12

10
Disconnect the transfer case shift control module.
Test the motor control A and B circuits for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 13
Go to Step 12

11
Replace the encoder motor. Refer to Transfer Case Motor/Encoder Replacement .

Did you complete the replacement?
--
Go to Step 13
--

12
Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement .

Did you complete the replacement?
--
Go to Step 13
--

13
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Setting the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK

Here's something for ya !

Good luck

DTC C0308
Circuit Description
The transfer case motor is a bi-directional, permanent magnet, D.C. motor. When energized, (through Motor Control A or Motor Control B, the ground is provided by the opposing motor control circuit and then grounded through the transfer case shift control module ground circuit), the motor, through a series of gears, rotates a shaft which moves the mode and range forks to shift the transfer case between 4H, 2H, N, and 4L ranges.

This DTC detects a short to ground in the motor control A or motor control B circuit.

Conditions for Setting the DTC
The system will test the motor circuits:
The system checks for unwanted voltage.
The system supplies voltage on one circuit and reads the voltage back on the other.
If the system detects a problem with the circuits, the DTC is logged.
The transfer case shift control module senses a low voltage return in Motor Control A or Motor Control B when a high voltage is expected.
Action Taken When the DTC Sets
All shifting will be disabled.
The SERVICE 4WD indicator lamp will be commanded on 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 no longer exists.
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 number(s) below refer to the step number(s) on the diagnostic table.

Listen for an audible motor noise when the transfer case encoder motor operates. Command both the ON and OFF states. Repeat the commands as necessary.

This step tests for a short to ground in the motor control A circuit.

This step tests for a short to ground in the motor control B circuit.

This step tests for a higher than normal resistance in the motor control A and B circuits through the module.

This step tests for a short to ground in the transfer case encoder motor windings.

This step tests for continuity across the motor circuit. Resistance readings vary depending on the location of the brush contact inside the motor assembly.

This step tests motor control A circuit for a short to ground.

This step tests motor control B circuit for a short to ground.

This step tests motor control A and B circuits for an open or high resistance.

Step
Action
Value(s)
Yes
No

Schematic Reference: Transfer Case Control Schematics

1
Was the Transfer Case Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check - Transfer Case

2
Start the vehicle.
Put the vehicle in NEUTRAL.
Using the transfer case control switches, attempt to shift through all modes and ranges.
Does the transfer case encoder motor turn ON and OFF?
--
Go to Testing for Intermittent and Poor Connections in Wiring Systems
Go to Step 3

3
Turn OFF the ignition.
Disconnect the four wire connector at the transfer case.
Connect a DMM between the motor control A circuit harness connector and ground at the transfer case.
Is the resistance reading less than the specified value?
10 K ohms
Go to Step 8
Go to Step 4

4
Connect a DMM between the motor control B circuit harness connector and ground at the transfer case.

Is the resistance reading less than the specified value?
10 K ohms
Go to Step 9
Go to Step 5

5
Connect a DMM between the motor control A and B circuit harness connector at the transfer case.

Is the resistance reading greater than the specified value?
2 ohms
Go to Step 10
Go to Step 6

6
Test terminals A and B at the transfer case side of the harness for a short to ground.

Was a problem found?
--
Go to Step 11
Go to Step 7

7
Test the resistance across the motor circuit.

Were the resistance readings within the specified range?
0.5-35 ohms
Go to Step 12
Go to Step 11

8
Disconnect the transfer case shift control module.
Test the motor control A 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 13
Go to Step 12

9
Disconnect the transfer case shift control module.
Test the motor control B circuit harness connector 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 13
Go to Step 12

10
Disconnect the transfer case shift control module.
Test the motor control A and B circuits for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 13
Go to Step 12

11
Replace the encoder motor. Refer to Transfer Case Motor/Encoder Replacement .

Did you complete the replacement?
--
Go to Step 13
--

12
Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement .

Did you complete the replacement?
--
Go to Step 13
--

13
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Setting the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK
thank you very much. it some where to start. i will keep you posted