GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 S10 Pickup - 2WD 🢒 Driveline/Axle 🢒 Transfer Case - NVG 136-NP4(One Speed Automatic) 🢒 DTC C0374 General System Malfunction

Circuit Description

The transfer case shift control module senses rear to front slip, a difference of rear to front propshaft speed, attempts to correct the difference by turning on the motor to apply torque to the front wheels.

Conditions for Setting the DTC

The transfer case shift control module is unable to correct sensed slip for 10 consecutive seconds. This DTC may set in conjunction with DTC C0305.

Action Taken When the DTC Sets
    • All clutch activation (slip control) will be disabled.
    • The SERVICE 4WD/AWD lamp will be latched on for the remainder of the current ignition cycle.

Conditions for Clearing the MIL/DTC
    • Current DTC
        The transfer case shift control module will clear the DTC if the condition for setting the DTC no longer exists.
    • History DTC
       - Once 100 consecutive ignition cycles without a fault present.
       - You issue a scan tool CLEAR CODES command.

Diagnostic Aids

An intermittent problem may be caused by a poor connection, break in the wire insulation exposing the internal wire, or a wire that is broken inside the insulation.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This test determines whether the transfer case shift control module has electronic control of the encoder motor.

    2.

  2. This test determines the internal integrity of the transfer case shift control module circuitry.

    3.

  3. This test determines if the transfer case is mechanically working properly.

Step

Action

Value(s)

Yes

No

1

Important:: If DTC C0300 or C0305 is also present, perform the diagnostic for these DTCs before continuing.

Was the Transfer Case Diagnostic System Check performed?

--

Go to Step 2

Go to Transfer Case Diagnostic System Check

2

  1. Place transmission in PARK.
  2. Turn the Ignition to the RUN position.
  3. Connect the Scan Tool .
  4. Use the scan tool to enable the encoder motor while under the vehicle .

Is the encoder motor engaging (buzzing noise)?

--

Go to Step 5

Go to Step 3

3

  1. Turn the ignition OFF.
  2. Disconnect the wire harness at the encoder motor.
  3. Turn the ignition switch to RUN.
  4. Use the scan tool to check for DTCs.

Did DTC C0310 set?

--

Go to Step 7

Go to Step 4

4

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

Has the transfer case shift control module been replaced?

--

Go to Step 8

--

5

  1. Remove the encoder motor assembly. Refer to Motor/Encoder Replacement .
  2. Connect a wrench to the transfer case sector shaft.
  3. Turn the sector shaft to apply and release the clutch pack.
  4. While the clutch pack is applied attempt to turn the front propshaft using a pry bar between the U-Joint.

Does the clutch hold the propshaft and prevent it from being turned?

--

Go to Step 7

Go to Step 6

6

Remove the transfer case and overhaul. Refer to Transfer Case Disassemble in the Transmission Unit Repair Manual (TURM).

Are the repairs complete?

--

Go to Step 8

--

7

Replace the transfer case encoder motor. Refer to Motor/Encoder Replacement .

Is the repair complete?

--

Go to Step 8

--

8

Clear all ATC DTCs.

Have all the ATC DTCs been cleared?

--

Go to Transfer Case Diagnostic System Check

--