NVG 263-NP1 (Selectable)

DTC B2725





Test 1-8





Test 9-13

Circuit Description
The transfer case shift control switch consists of three normally open switches. The transfer case shift control module supplies a regulated 8 volts DC to the switch through the 8 volt reference circuit. The current travels through a 9.09 KU resistor located inside the switch. The switch returns current to the transfer case shift control module through the 4WD switch signal circuit.
The transfer case shift control module constantly monitors this signal voltage in order to determine the condition of the shift control switch circuit. If no buttons are pressed, and the transfer case shift control module detects a voltage level outside the possible range (approximately -0.5 to 1.0 volts) for longer than 5 minutes, the transfer case shift control module will set this DTC or if a button is held down or sticks for a period longer than 5 minutes.
When each of the switches is depressed they will complete a circuit through their own specific resistor. The transfer case shift control module continuously monitors the switch input to determine whether the 41-11, 21-11, and 41-0 button selections are made by the driver. Neutral may be obtained if the following conditions are met:
^ The engine is running.
^ The automatic transmission is in neutral (or the clutch pedal is depressed on a manual transmission application).
^ The vehicle speed is below 3 MPH.
^ The transfer case is in the 2HI mode.
Once these conditions have been met, pressing and holding both the 2HI and 41-0 buttons for 10 seconds will shift the transfer case into neutral, turning on the red neutral indicator lamp.

Conditions for Setting the DTC
^ The system constantly monitors the voltage on the 4WD switch signal circuit.
^ If the system detects a voltage level outside the possible range produced when no buttons are depressed, (approximately -0.5 to 1.0 volts), the DTC is logged.

Action Taken When the DTC Sets
^ All shifting will be disabled.
^ The SERVICE 4WD indicator lamp will be latched on for the remainder of the current ignition cycle.

Conditions for Clearing the DTC
^ The transfer case shift control module will clear the current 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.
2. This step tests for proper operation of the transfer case shift control switch.
3. This step tests for proper voltage supply to the transfer case shift control switch.
4. This step tests the transfer case shift control switch for proper resistance values in all switch states.
5. This step tests the 4WD switch signal circuit for a short to voltage.
6. This step tests the 4WD switch signal circuit for an open or short to ground.
7. This step tests the 4WD switch signal circuit for a short to the 8 volt reference circuit.
8. Determines whether the 8 volt reference circuit is greater than or less than the specified voltage.
9. This step tests the 8 volt reference circuit for a short to voltage.
10. This step tests the 8 volt reference circuit for an open or short to ground.