C0300

DTC C0300

Circuit Description
The 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 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 Setting the DTC The system will log 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:
^ Transmission is NOT in Park/Neutral
^ Engine is running
^ Front axle is engaged
^ Vehicle Speed On Class 2 Data bus exceeds 1 0 mph

Action Taken When the DTC Sets
^ All Shifts to AUTO 4WD mode will be disabled. If the current mode is AUTO 4WD, the system will not allow any further adaptive events (correct wheel slip).
^ The SERVICE 4WD indicator 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 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 numbers below refer to the step numbers on the diagnostic table.
2. Tests to see if the malfunction is intermittent.
3. Tests the internal resistance of the propshaft speed sensor.
4. Tests to see if the propshaft speed sensor can generate a sufficient amount of AC voltage.
5. Tests the RSS LO circuit for a short to ground, a high resistance, or an open.
6. Tests the RSS HI circuit for a short to ground, a high resistance, or an open.
7. Tests the RSS HI circuit for a short to voltage.
8. Tests the RSS LO circuit for a short to voltage.
9. Tests the RSS HI circuit for a short to the RSS LO circuit.