B0770
DTC B0770
Circuit Description
The All Wheel Drive (AWD) indicator circuit consists of an indicator lamp feed circuit and an AWD indicator lamp control circuit. When the AWD mode has been selected, current is supplied to the AWD indicator lamp by the indicator lamp feed circuit, traveling through the AWD indicator lamp LED, at which time the transfer case shift control module supplies the ground through the AWD indicator lamp control circuit.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B0770 All Wheel Drive (AWD) Indicator Circuit Malfunction
Conditions for Running the DTC
- The ignition is ON.
- System voltage is 9-18 volts.
Conditions for Setting the DTC
- The system monitors the voltage on the AWD indicator control circuit.
- If the system detects a voltage of 2 volts or less for 1.5 seconds when the AWD indicator is not commanded, the DTC is logged.
- If the system detects a voltage of 4.5 volts or more when the AWD indicator is commanded, the DTC is logged.
Action Taken When the DTC Sets
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.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. This step looks for the visual operation of the AWD indicator. Command both the ON and OFF states.
3. This step helps determine if proper voltage is supplied to the transfer case select switch.
4. This step helps determine if there is a short to ground in the indicator control circuit.
5. This step helps determine if there is an open in the indicator control circuit.
6. This step tests the indicator feed circuit for an open or high resistance.
7. This step tests the AWD indicator control circuit for a short to ground.
8. This step tests the AWD indicator control circuit for an open or high resistance.
