NVG 233-NP1 2 Speed Automatic 4WD Transfer Case

Diagnostic Chart:

Wiring Diagram:

Circuit Description
The Front and Rear Propshaft Speed Sensor is a Permanent Magnet (PM) generator. The PM generator produces a pulsing AC voltage. The AC voltage level and number of pulses increases as speed increases. The module converts the pulsating AC voltage to a propshaft RPM which is used for calculations. The module converts the pulsating AC voltage to a propshaft RPM which is used for calculations. The propshaft RPM cab be displayed with a scan tool.

This DTC detects greater than 20% difference in the speed sensor inputs.

Conditions for Setting the DTC
The Automatic 4WD Transfer Case (ATC) Control Module detects continued readings of front and rear propshaft speed signals which do not match. The Module cannot determine propshaft speed.

The system will log the DTC if the front and rear propshaft inputs indicates a speed of less than 20% difference to 40 seconds while all of the following are true:
- Transmission NOT in Park/Neutral
- Engine is running
- Front Propshaft indicates speed less than 75 MPH
- Front Propshaft or Rear Propshaft speed exceeds 512 RPM
- Vehicle Speed On Class 2 Data bus exceeds 10 MPH

Action Taken When the DTC Sets
- All Shifts to AUTO (Adapt) mode will be disabled. If the current mode is AUTO, the system will not allow any further adaptive events (correct slip).
- The service 4WD lamp will be latched on for the remainder of the current ignition cycle.

Conditions for Clearing the DTC
- The Automatic 4WD Transfer Case (ATC) 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.