GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The transfer case shift control module uses the VIN information for calculations that are required for the different calibrations used based on axle ratio, transmission, tire size, and engine. The system does not know which calibration to use without this information.

Conditions for Setting the DTC

The transfer case shift control module does not receive a valid VIN digit for the correct application, K truck, L van or T truck within 3 seconds after power up.

Action Taken When the DTC Sets

    • The ignition counts since last fault will be cleared.
    • The system will be disabled until valid VIN data is received.
    • The SERVICE AWD/4WD lamp will be latched on.

Conditions for Clearing the MIL/DTC

A history DTC will clear after a valid VIN digit is received.

Possible Causes

Class 2 Data bus malfunction, Vehicle Control Module (VCM) malfunction, module installed in wrong vehicle.

Diagnostic Aids

  1. Using a Scan Tool , check all components connected to the Class 2 serial data line.
  2. Check the Vehicle Control Module (VCM) calibration for a miscalibrated EEPROM
  3. Check the transfer case shift control module part number for an incorrect part number

DTC C0611 VIN Information Error

Step

Action

Value(s)

Yes

No

1

Was the Transfer Case Diagnostic System Check performed?

--

Go to Step 2

Go to Transfer Case Diagnostic System Check

2

Using a Scan Tool , check all the components connected to the Class 2 serial data line.

Refer to Data Link Connector diagnosis in Electrical Diagnosis.

Is the Class 2 serial data line communicating properly?

--

Go to Step 3

Go to Data Link Connector diagnosis in Electrical Diagnosis.

3

Check the VCM EEPROM calibration.

Refer to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls.

Is the VCM calibration correct?

--

Go to Step 4

Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls.

4

Check the transfer case shift control module for the correct part number.

Is the transfer case shift control module part number correct?

--

Go to Step 5

Go to Step 5

5

Replace the transfer shift control module with the correct part number.

Have all the ATC components been reconnected and properly mounted?

--

Go to Transfer Case Diagnostic System Check

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