Diesel Data: Automotive Repair

B0790

DTC B0790

CIRCUIT DESCRIPTION
The neutral indicator circuit consists of a ignition 3 voltage circuit and a neutral indicator control circuit. When the neutral mode has been selected by the driver, current is supplied to the neutral indicator by the ignition 3 voltage circuit, traveling through the neutral indicator LED at which time the transfer case shift control module supplies the ground through the neutral indicator control circuit. This DTC indicates an open, short to ground or a short to voltage.

CONDITIONS FOR RUNNING THE DTC
- Ignition is ON.
- System voltage is 9-18 volts.

CONDITIONS FOR SETTING THE DTC
- The system monitors the voltage on the neutral indicator control circuit.
- If the system detects a voltage 3.5 volts or less when the neutral indicator is not commanded, the DTC is logged.
- If the system detects a voltage 3.5 volts or more when the neutral indicator is commanded, the DTC is logged.

ACTION TAKEN WHEN THE DTC SETS
The SERVICE 4WD indicator will remain illuminated 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 is not currently present.
- A history DTC will clear after 33 consecutive ignition cycles without a fault present.
- History DTCs can be cleared using a scan tool.

TEST DESCRIPTION

Steps 1-9:




The numbers below refer to the step numbers on the diagnostic table.
2. Tests for voltage at the ignition 3 voltage side of the transfer case select switch.
3. Tests the control circuit of the neutral indicator for a short to voltage or an open.
4. Tests the control circuit of the neutral indicator for a short to ground.