Diagnostic Instructions
DTC Descriptor
DTC B2725: ATC Mode Switch Circuit Malfunction
Circuit/System Description
The range/mode switch circuit consists of 4 modes. The transfer case shift control module supplies 5 volts to the switch through the 5-volt reference circuit. The current travel through the resistor of the currently active mode. The current
is then returned to the transfer case shift control module through the switch signal circuit.
The transfer case shift control module constantly monitors this signal voltage to determine the condition of the mode switch circuit.
When each of the modes are selected they complete a circuit through their own specific resistor. The transfer case shift control module continuously monitors the switch input to determine whether the Neutral, 2HI, 4HI, or 4LO mode was selected by the driver.
Conditions for Running the DTC
| • | The system voltage is 9-18 volts. |
Conditions for Setting the DTC
| • | The system constantly monitors the voltage on switch signal circuit. |
| • | If the system detects a voltage level under 0.35 volt or greater than 0.70 volt for 60 seconds, the DTC is logged. |
Action Taken When the DTC Sets
| • | All shifting is disabled. |
| • | The SERVICE 4WD indicator is not illuminated. |
Conditions for Clearing the DTC
| • | The transfer case shift control module will clear the current DTC if the condition for setting the DTC is not currently present. |
| • | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
| • | History DTCs can be cleared using a scan tool. |
Reference Information
Schematic Reference
Transfer Case Control Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Transfer Case Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References
for scan tool information.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
