Diagnostic Instructions
DTC Descriptor
DTC C0300: Rear Speed Sensor Malfunction
Circuit/System Description
The rear propshaft speed sensor is a permanent magnet generator. The permanent magnet generator produces a pulsing AC voltage. The AC voltage level and number of pulses increase as speed increases. The module converts the pulsating AC voltage to a propshaft
RPM which is used for calculations. The propshaft RPM can be displayed with a scan tool.
This DTC detects an open, short to ground, short to voltage or faulty sensor.
Conditions for Running the DTC
| • | System voltage is 9-18 volts. |
| • | Vehicle speed exceeds 16 km/h (10 mph). |
Conditions for Setting the DTC
The system logs the DTC if the rear propshaft input indicates a speed of less than 16 RPM for 30 seconds while all of the following are true:
| • | The transmission is NOT in PARK/NEUTRAL. |
| • | The engine is running. |
| • | The front axle is engaged. |
| • | Vehicle speed on Class 2 data bus exceeds 16 km/h (10 mph). |
Action Taken When the DTC Sets
| • | All shifts to AUTO or the Adapt mode, is disabled. If the current mode is AUTO, the system does not allow any further adaptive events, such as correcting slip. |
| • | The SERVICE 4WD indicator remains illuminated for the remainder of the current ignition cycle. |
Conditions for Clearing the DTC
| • | The transfer case shift control module clears the DTC if the condition for setting the DTC is not currently present. |
| • | A history DTC clears 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.
